(Slip Opinion)              OCTOBER TERM, 2014                                       1

                                       Syllabus

         NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
       being done in connection with this case, at the time the opinion is issued.
       The syllabus constitutes no part of the opinion of the Court but has been
       prepared by the Reporter of Decisions for the convenience of the reader.
       See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.


SUPREME COURT OF THE UNITED STATES

                                       Syllabus

                  GLOSSIP ET AL. v. GROSS ET AL.

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR
                 THE TENTH CIRCUIT

      No. 14–7955. Argued April 29, 2015—Decided June 29, 2015
Because capital punishment is constitutional, there must be a constitu-
  tional means of carrying it out. After Oklahoma adopted lethal injec-
  tion as its method of execution, it settled on a three-drug protocol of
  (1) sodium thiopental (a barbiturate) to induce a state of uncon-
  sciousness, (2) a paralytic agent to inhibit all muscular-skeletal
  movements, and (3) potassium chloride to induce cardiac arrest. In
  Baze v. Rees, 553 U. S. 35, the Court held that this protocol does not
  violate the Eighth Amendment’s prohibition against cruel and unu-
  sual punishments. Anti-death-penalty advocates then pressured
  pharmaceutical companies to prevent sodium thiopental (and, later,
  another barbiturate called pentobarbital) from being used in execu-
  tions. Unable to obtain either sodium thiopental or pentobarbital,
  Oklahoma decided to use a 500-milligram dose of midazolam, a seda-
  tive, as the first drug in its three-drug protocol.
     Oklahoma death-row inmates filed a 42 U. S. C. §1983 action
  claiming that the use of midazolam violates the Eighth Amendment.
  Four of those inmates filed a motion for a preliminary injunction and
  argued that a 500-milligram dose of midazolam will not render them
  unable to feel pain associated with administration of the second and
  third drugs. After a three-day evidentiary hearing, the District Court
  denied the motion. It held that the prisoners failed to identify a
  known and available alternative method of execution that presented
  a substantially less severe risk of pain. It also held that the prison-
  ers failed to establish a likelihood of showing that the use of midazo-
  lam created a demonstrated risk of severe pain. The Tenth Circuit
  affirmed.
Held: Petitioners have failed to establish a likelihood of success on the
 merits of their claim that the use of midazolam violates the Eighth
2                           GLOSSIP v. GROSS

                                  Syllabus

    Amendment. Pp. 11–29.
       (a) To obtain a preliminary injunction, petitioners must establish,
    among other things, a likelihood of success on the merits of their
    claim. See Winter v. Natural Resources Defense Council, Inc., 555
    U. S. 7, 20. To succeed on an Eighth Amendment method-of-
    execution claim, a prisoner must establish that the method creates a
    demonstrated risk of severe pain and that the risk is substantial
    when compared to the known and available alternatives. Baze, su-
    pra, at 61 (plurality opinion). Pp. 11–13.
       (b) Petitioners failed to establish that any risk of harm was sub-
    stantial when compared to a known and available alternative method
    of execution. Petitioners have suggested that Oklahoma could exe-
    cute them using sodium thiopental or pentobarbital, but the District
    Court did not commit a clear error when it found that those drugs are
    unavailable to the State. Petitioners argue that the Eighth Amend-
    ment does not require them to identify such an alternative, but their
    argument is inconsistent with the controlling opinion in Baze, which
    imposed a requirement that the Court now follows. Petitioners also
    argue that the requirement to identify an alternative is inconsistent
    with the Court’s pre-Baze decision in Hill v. McDonough, 547 U. S.
    573, but they misread that decision. Hill concerned a question of civ-
    il procedure, not a substantive Eighth Amendment question. That
    case held that §1983 alone does not require an inmate asserting a
    method-of-execution claim to plead an acceptable alternative. Baze,
    on the other hand, made clear that the Eighth Amendment requires a
    prisoner to plead and prove a known and available alternative.
    Pp. 13–16.
       (c) The District Court did not commit clear error when it found that
    midazolam is likely to render a person unable to feel pain associated
    with administration of the paralytic agent and potassium chloride.
    Pp. 16–29.
          (1) Several initial considerations bear emphasis. First, the Dis-
    trict Court’s factual findings are reviewed under the deferential
    “clear error” standard. Second, petitioners have the burden of per-
    suasion on the question whether midazolam is effective. Third, the
    fact that numerous courts have concluded that midazolam is likely to
    render an inmate insensate to pain during execution heightens the
    deference owed to the District Court’s findings. Finally, challenges to
    lethal injection protocols test the boundaries of the authority and
    competency of federal courts, which should not embroil themselves in
    ongoing scientific controversies beyond their expertise. Baze, supra,
    at 51. Pp. 16–18.
          (2) The State’s expert presented persuasive testimony that a 500-
    milligram dose of midazolam would make it a virtual certainty that
                     Cite as: 576 U. S. ____ (2015)                      3

                                Syllabus

  an inmate will not feel pain associated with the second and third
  drugs, and petitioners’ experts acknowledged that they had no con-
  trary scientific proof. Expert testimony presented by both sides lends
  support to the District Court’s conclusion. Evidence suggested that a
  500-milligram dose of midazolam will induce a coma, and even one of
  petitioners’ experts agreed that as the dose of midazolam increases, it
  is expected to produce a lack of response to pain. It is not dispositive
  that midazolam is not recommended or approved for use as the sole
  anesthetic during painful surgery. First, the 500-milligram dose at
  issue here is many times higher than a normal therapeutic dose.
  Second, the fact that a low dose of midazolam is not the best drug for
  maintaining unconsciousness says little about whether a 500-
  milligram dose is constitutionally adequate to conduct an execution.
  Finally, the District Court did not err in concluding that the safe-
  guards adopted by Oklahoma to ensure proper administration of
  midazolam serve to minimize any risk that the drug will not operate
  as intended. Pp. 18–22.
       (3) Petitioners’ speculative evidence regarding midazolam’s “ceil-
  ing effect” does not establish that the District Court’s findings were
  clearly erroneous. The mere fact that midazolam has a ceiling above
  which an increase in dosage produces no effect cannot be dispositive,
  and petitioners provided little probative evidence on the relevant
  question, i.e., whether midazolam’s ceiling effect occurs below the
  level of a 500-milligram dose and at a point at which the drug does
  not have the effect of rendering a person insensate to pain caused by
  the second and third drugs. Petitioners attempt to deflect attention
  from their failure of proof on this point by criticizing the testimony of
  the State’s expert. They emphasize an apparent conflict between the
  State’s expert and their own expert regarding the biological process
  that produces midazolam’s ceiling effect. But even if petitioners’ ex-
  pert is correct regarding that biological process, it is largely beside
  the point. What matters for present purposes is the dosage at which
  the ceiling effect kicks in, not the biological process that produces the
  effect. Pp. 22–25.
       (4) Petitioners’ remaining arguments—that an expert report pre-
  sented in the District Court should have been rejected because it ref-
  erenced unreliable sources and contained an alleged mathematical
  error, that only four States have used midazolam in an execution,
  and that difficulties during two recent executions suggest that mid-
  azolam is ineffective—all lack merit. Pp. 26–29.
776 F. 3d 721, affirmed.

  ALITO, J., delivered the opinion of the Court, in which ROBERTS, C. J.,
and SCALIA, KENNEDY, and THOMAS, JJ., joined. SCALIA, J., filed a con-
4                         GLOSSIP v. GROSS

                                Syllabus

curring opinion, in which THOMAS, J., joined. THOMAS, J., filed a con-
curring opinion, in which SCALIA, J., joined. BREYER, J., filed a dissent-
ing opinion, in which GINSBURG, J., joined. SOTOMAYOR, J., filed a dis-
senting opinion, in which GINSBURG, BREYER, and KAGAN, JJ., joined.
                        Cite as: 576 U. S. ____ (2015)                              1

                             Opinion of the Court

     NOTICE: This opinion is subject to formal revision before publication in the
     preliminary print of the United States Reports. Readers are requested to
     notify the Reporter of Decisions, Supreme Court of the United States, Wash-
     ington, D. C. 20543, of any typographical or other formal errors, in order
     that corrections may be made before the preliminary print goes to press.


SUPREME COURT OF THE UNITED STATES
                                   _________________

                                   No. 14–7955
                                   _________________


    RICHARD E. GLOSSIP, ET AL., PETITIONERS v.


             KEVIN J. GROSS, ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE TENTH CIRCUIT


                                 [June 29, 2015] 


   JUSTICE ALITO delivered the opinion of the Court.
   Prisoners sentenced to death in the State of Oklahoma
filed an action in federal court under Rev. Stat. §1979, 42
U. S. C. §1983, contending that the method of execution
now used by the State violates the Eighth Amendment
because it creates an unacceptable risk of severe pain.
They argue that midazolam, the first drug employed in the
State’s current three-drug protocol, fails to render a per-
son insensate to pain. After holding an evidentiary hear-
ing, the District Court denied four prisoners’ application
for a preliminary injunction, finding that they had failed
to prove that midazolam is ineffective. The Court of Ap-
peals for the Tenth Circuit affirmed and accepted the
District Court’s finding of fact regarding midazolam’s
efficacy.
   For two independent reasons, we also affirm. First, the
prisoners failed to identify a known and available alterna-
tive method of execution that entails a lesser risk of pain,
a requirement of all Eighth Amendment method-of-
execution claims. See Baze v. Rees, 553 U. S. 35, 61 (2008)
(plurality opinion). Second, the District Court did not
2                    GLOSSIP v. GROSS

                     Opinion of the Court

commit clear error when it found that the prisoners failed
to establish that Oklahoma’s use of a massive dose of
midazolam in its execution protocol entails a substantial
risk of severe pain.
                                 I

                                A

    The death penalty was an accepted punishment at the
time of the adoption of the Constitution and the Bill of
Rights. In that era, death sentences were usually carried
out by hanging. The Death Penalty in America: Current
Controversies 4 (H. Bedau ed. 1997). Hanging remained
the standard method of execution through much of the
19th century, but that began to change in the century’s
later years. See Baze, supra, at 41–42. In the 1880’s, the
Legislature of the State of New York appointed a commis-
sion to find “ ‘the most humane and practical method
known to modern science of carrying into effect the sen-
tence of death in capital cases.’ ” In re Kemmler, 136 U. S.
436, 444 (1890). The commission recommended electrocu-
tion, and in 1888, the Legislature enacted a law providing
for this method of execution. Id., at 444–445. In subse-
quent years, other States followed New York’s lead in the
“ ‘belief that electrocution is less painful and more humane
than hanging.’ ” Baze, 553 U. S., at 42 (quoting Malloy v.
South Carolina, 237 U. S. 180, 185 (1915)).
    In 1921, the Nevada Legislature adopted another new
method of execution, lethal gas, after concluding that this
was “the most humane manner known to modern science.”
State v. Jon, 46 Nev. 418, 437, 211 P. 676, 682 (1923). The
Nevada Supreme Court rejected the argument that the
use of lethal gas was unconstitutional, id., at 435–437, 211
P., at 681–682, and other States followed Nevada’s lead,
see, e.g., Ariz. Const., Art. XXII, §22 (1933); 1937 Cal.
Stats. ch. 172, §1; 1933 Colo. Sess. Laws ch. 61, §1; 1955
Md. Laws ch. 625, §1, p. 1017; 1937 Mo. Laws p. 222, §1.
                 Cite as: 576 U. S. ____ (2015)            3

                     Opinion of the Court

Nevertheless, hanging and the firing squad were retained
in some States, see, e.g., 1961 Del. Laws ch. 309, §2 (hang-
ing); 1935 Kan. Sess. Laws ch. 155, §1 (hanging); Utah
Code Crim. Proc. §105–37–16 (1933) (hanging or firing
squad), and electrocution remained the predominant
method of execution until the 9-year hiatus in executions
that ended with our judgment in Gregg v. Georgia, 428
U. S. 153 (1976). See Baze, supra, at 42.
  After Gregg reaffirmed that the death penalty does not
violate the Constitution, some States once again sought a
more humane way to carry out death sentences. They
eventually adopted lethal injection, which today is “by far
the most prevalent method of execution in the United
States.” Baze, supra, at 42. Oklahoma adopted lethal
injection in 1977, see 1977 Okla. Sess. Laws p. 89, and it
eventually settled on a protocol that called for the use of
three drugs: (1) sodium thiopental, “a fast-acting barbitu-
rate sedative that induces a deep, comalike unconscious-
ness when given in the amounts used for lethal injection,”
(2) a paralytic agent, which “inhibits all muscular-skeletal
movements and, by paralyzing the diaphragm, stops respi-
ration,” and (3) potassium chloride, which “interferes with
the electrical signals that stimulate the contractions of the
heart, inducing cardiac arrest.” Baze, supra, at 44; see
also Brief for Respondents 9. By 2008, at least 30 of the
36 States that used lethal injection employed that particu-
lar three-drug protocol. 553 U. S., at 44.
  While methods of execution have changed over the
years, “[t]his Court has never invalidated a State’s chosen
procedure for carrying out a sentence of death as the
infliction of cruel and unusual punishment.” Id., at 48. In
Wilkerson v. Utah, 99 U. S. 130, 134–135 (1879), the Court
upheld a sentence of death by firing squad. In In re
Kemmler, supra, at 447–449, the Court rejected a chal-
lenge to the use of the electric chair. And the Court did
not retreat from that holding even when presented with a
4                    GLOSSIP v. GROSS

                     Opinion of the Court

case in which a State’s initial attempt to execute a pris-
oner by electrocution was unsuccessful. Louisiana ex rel.
Francis v. Resweber, 329 U. S. 459, 463–464 (1947) (plu-
rality opinion). Most recently, in Baze, supra, seven Jus-
tices agreed that the three-drug protocol just discussed
does not violate the Eighth Amendment.
   Our decisions in this area have been animated in part
by the recognition that because it is settled that capital
punishment is constitutional, “[i]t necessarily follows that
there must be a [constitutional] means of carrying it out.”
Id., at 47. And because some risk of pain is inherent in
any method of execution, we have held that the Constitu-
tion does not require the avoidance of all risk of pain.
Ibid. After all, while most humans wish to die a painless
death, many do not have that good fortune. Holding that
the Eighth Amendment demands the elimination of essen-
tially all risk of pain would effectively outlaw the death
penalty altogether.
                               B
   Baze cleared any legal obstacle to use of the most com-
mon three-drug protocol that had enabled States to carry
out the death penalty in a quick and painless fashion. But
a practical obstacle soon emerged, as anti-death-penalty
advocates pressured pharmaceutical companies to refuse
to supply the drugs used to carry out death sentences.
The sole American manufacturer of sodium thiopental, the
first drug used in the standard three-drug protocol, was
persuaded to cease production of the drug. After suspend-
ing domestic production in 2009, the company planned to
resume production in Italy. Koppel, Execution Drug Halt
Raises Ire of Doctors, Wall Street Journal, Jan. 25, 2011,
p. A6. Activists then pressured both the company and the
Italian Government to stop the sale of sodium thiopental
for use in lethal injections in this country. Bonner, Letter
from Europe: Drug Company in Cross Hairs of Death
                 Cite as: 576 U. S. ____ (2015)           5

                     Opinion of the Court

Penalty Opponents, N. Y. Times, Mar. 30, 2011; Koppel,
Drug Halt Hinders Executions in the U. S., Wall Street
Journal, Jan. 22, 2011, p. A1. That effort proved success-
ful, and in January 2011, the company announced that it
would exit the sodium thiopental market entirely. See
Hospira, Press Release, Hospira Statement Regarding
PentothalTM (sodium thiopental) Market Exit (Jan. 21,
2011).
   After other efforts to procure sodium thiopental proved
unsuccessful, States sought an alternative, and they even-
tually replaced sodium thiopental with pentobarbital,
another barbiturate. In December 2010, Oklahoma be-
came the first State to execute an inmate using pentobar-
bital. See Reuters, Chicago Tribune, New Drug Mix Used
in Oklahoma Execution, Dec. 17 2010, p. 41. That execu-
tion occurred without incident, and States gradually shifted
to pentobarbital as their supplies of sodium thiopental
ran out. It is reported that pentobarbital was used in all
of the 43 executions carried out in 2012. The Death
Penalty Institute, Execution List 2012, online at www.
deathpenaltyinfo.org/execution-list-2012     (all   Internet
materials as visited June 26, 2015, and available in Clerk
of Court’s case file). Petitioners concede that pentobarbi-
tal, like sodium thiopental, can “reliably induce and main-
tain a comalike state that renders a person insensate to
pain” caused by administration of the second and third
drugs in the protocol. Brief for Petitioners 2. And courts
across the country have held that the use of pentobarbital
in executions does not violate the Eighth Amendment.
See, e.g., Jackson v. Danberg, 656 F. 3d 157 (CA3 2011);
Beaty v. Brewer, 649 F. 3d 1071 (CA9 2011); DeYoung v.
Owens, 646 F. 3d 1319 (CA11 2011); Pavatt v. Jones, 627
F. 3d 1336 (CA10 2010).
   Before long, however, pentobarbital also became una-
vailable. Anti-death-penalty advocates lobbied the Danish
manufacturer of the drug to stop selling it for use in exe-
6                    GLOSSIP v. GROSS

                     Opinion of the Court

cutions. See Bonner, supra. That manufacturer opposed
the death penalty and took steps to block the shipment of
pentobarbital for use in executions in the United States.
Stein, New Obstacle to Death Penalty in U. S., Washing-
ton Post, July 3, 2011, p. A4. Oklahoma eventually be-
came unable to acquire the drug through any means. The
District Court below found that both sodium thiopental
and pentobarbital are now unavailable to Oklahoma. App.
67–68.
                             C
  Unable to acquire either sodium thiopental or pentobar-
bital, some States have turned to midazolam, a sedative in
the benzodiazepine family of drugs. In October 2013,
Florida became the first State to substitute midazolam for
pentobarbital as part of a three-drug lethal injection pro-
tocol. Fernandez, Executions Stall As States Seek Differ-
ent Drugs, N. Y. Times, Nov. 9, 2013, p. A1. To date,
Florida has conducted 11 executions using that protocol,
which calls for midazolam followed by a paralytic agent
and potassium chloride. See Brief for State of Florida as
Amicus Curiae 2–3; Chavez v. Florida SP Warden, 742
F. 3d 1267, 1269 (CA11 2014). In 2014, Oklahoma also
substituted midazolam for pentobarbital as part of its
three-drug protocol. Oklahoma has already used this
three-drug protocol twice: to execute Clayton Lockett in
April 2014 and Charles Warner in January 2015. (Warner
was one of the four inmates who moved for a preliminary
injunction in this case.)
  The Lockett execution caused Oklahoma to implement
new safety precautions as part of its lethal injection proto-
col. When Oklahoma executed Lockett, its protocol called
for the administration of 100 milligrams of midazolam, as
compared to the 500 milligrams that are currently re-
quired. On the morning of his execution, Lockett cut
himself twice at “ ‘the bend of the elbow.’ ” App. 50. That
                 Cite as: 576 U. S. ____ (2015)           7

                     Opinion of the Court

evening, the execution team spent nearly an hour making
at least one dozen attempts to establish intravenous (IV)
access to Lockett’s cardiovascular system, including at his
arms and elsewhere on his body. The team eventually
believed that it had established intravenous access
through Lockett’s right femoral vein, and it covered the
injection access point with a sheet, in part to preserve
Lockett’s dignity during the execution. After the team
administered the midazolam and a physician determined
that Lockett was unconscious, the team next administered
the paralytic agent (vecuronium bromide) and most of the
potassium chloride. Lockett began to move and speak, at
which point the physician lifted the sheet and determined
that the IV had “infiltrated,” which means that “the IV
fluid, rather than entering Lockett’s blood stream, had
leaked into the tissue surrounding the IV access point.”
Warner v. Gross, 776 F. 3d 721, 725 (CA10 2015) (case
below). The execution team stopped administering the
remaining potassium chloride and terminated the execu-
tion about 33 minutes after the midazolam was first in-
jected. About 10 minutes later, Lockett was pronounced
dead.
   An investigation into the Lockett execution concluded
that “the viability of the IV access point was the single
greatest factor that contributed to the difficulty in admin-
istering the execution drugs.” App. 398. The investiga-
tion, which took five months to complete, recommended
several changes to Oklahoma’s execution protocol, and
Oklahoma adopted a new protocol with an effective date of
September 30, 2014. That protocol allows the Oklahoma
Department of Corrections to choose among four different
drug combinations. The option that Oklahoma plans to
use to execute petitioners calls for the administration of
500 milligrams of midazolam followed by a paralytic agent
8                       GLOSSIP v. GROSS

                        Opinion of the Court

and potassium chloride.1 The paralytic agent may be
pancuronium bromide, vecuronium bromide, or rocuronium
bromide, three drugs that, all agree, are functionally
equivalent for purposes of this case. The protocol also
includes procedural safeguards to help ensure that an
inmate remains insensate to any pain caused by the ad-
ministration of the paralytic agent and potassium chlo-
ride. Those safeguards include: (1) the insertion of both a
primary and backup IV catheter, (2) procedures to confirm
the viability of the IV site, (3) the option to postpone an
execution if viable IV sites cannot be established within an
hour, (4) a mandatory pause between administration of
the first and second drugs, (5) numerous procedures for
monitoring the offender’s consciousness, including the use
of an electrocardiograph and direct observation, and
(6) detailed provisions with respect to the training and
preparation of the execution team. In January of this
year, Oklahoma executed Warner using these revised
procedures and the combination of midazolam, a paralytic
agent, and potassium chloride.
                            II


                            A

  In June 2014, after Oklahoma switched from pentobar-
bital to midazolam and executed Lockett, 21 Oklahoma
death row inmates filed an action under 42 U. S. C. §1983
challenging the State’s new lethal injection protocol. The
complaint alleged that Oklahoma’s use of midazolam
violates the Eighth Amendment’s prohibition of cruel and
unusual punishment.
  In November 2014, four of those plaintiffs—Richard

——————
    1 The
        three other drug combinations that Oklahoma may admin-
ister are: (1) a single dose of pentobarbital, (2) a single dose of
sodium thiopental, and (3) a dose of midazolam followed by a dose of
hydromorphone.
                 Cite as: 576 U. S. ____ (2015)            9

                     Opinion of the Court

Glossip, Benjamin Cole, John Grant, and Warner—filed a
motion for a preliminary injunction. All four men had
been convicted of murder and sentenced to death by Okla-
homa juries. Glossip hired Justin Sneed to kill his em-
ployer, Barry Van Treese. Sneed entered a room where
Van Treese was sleeping and beat him to death with a
baseball bat. See Glossip v. State, 2007 OK CR 12, 157
P. 3d 143, 147–149. Cole murdered his 9-month-old
daughter after she would not stop crying. Cole bent her
body backwards until he snapped her spine in half. After
the child died, Cole played video games. See Cole v. State,
2007 OK CR 27, 164 P. 3d 1089, 1092–1093. Grant, while
serving terms of imprisonment totaling 130 years, killed
Gay Carter, a prison food service supervisor, by pulling
her into a mop closet and stabbing her numerous times
with a shank. See Grant v. State, 2002 OK CR 36, 58
P. 3d 783, 789. Warner anally raped and murdered an 11-
month-old girl. The child’s injuries included two skull
fractures, internal brain injuries, two fractures to her jaw,
a lacerated liver, and a bruised spleen and lungs. See
Warner v. State, 2006 OK CR 40, 144 P. 3d 838, 856–857.
  The Oklahoma Court of Criminal Appeals affirmed the
murder conviction and death sentence of each offender.
Each of the men then unsuccessfully sought both state
postconviction and federal habeas corpus relief. Having
exhausted the avenues for challenging their convictions
and sentences, they moved for a preliminary injunction
against Oklahoma’s lethal injection protocol.
                            B
  In December 2014, after discovery, the District Court
held a 3-day evidentiary hearing on the preliminary in-
junction motion. The District Court heard testimony from
17 witnesses and reviewed numerous exhibits. Dr. David
Lubarsky, an anesthesiologist, and Dr. Larry Sasich, a
doctor of pharmacy, provided expert testimony about
10                    GLOSSIP v. GROSS

                      Opinion of the Court

midazolam for petitioners, and Dr. Roswell Evans, a
doctor of pharmacy, provided expert testimony for
respondents.
   After reviewing the evidence, the District Court issued
an oral ruling denying the motion for a preliminary in-
junction. The District Court first rejected petitioners’
challenge under Daubert v. Merrell Dow Pharmaceuticals,
Inc., 509 U. S. 579 (1993), to the testimony of Dr. Evans.
It concluded that Dr. Evans, the Dean of Auburn Universi-
ty’s School of Pharmacy, was well qualified to testify about
midazolam’s properties and that he offered reliable testi-
mony. The District Court then held that petitioners failed
to establish a likelihood of success on the merits of their
claim that the use of midazolam violates the Eighth
Amendment. The court provided two independent reasons
for this conclusion. First, the court held that petitioners
failed to identify a known and available method of execu-
tion that presented a substantially less severe risk of pain
than the method that the State proposed to use. Second,
the court found that petitioners failed to prove that Okla-
homa’s protocol “presents a risk that is ‘sure or very likely
to cause serious illness and needless suffering,’ amounting
to ‘an objectively intolerable risk of harm.’ ” App. 96 (quot-
ing Baze, 553 U. S., at 50). The court emphasized that the
Oklahoma protocol featured numerous safeguards, includ-
ing the establishment of two IV access sites, confirmation
of the viability of those sites, and monitoring of the offend-
er’s level of consciousness throughout the procedure.
   The District Court supported its decision with findings
of fact about midazolam. It found that a 500-milligram
dose of midazolam “would make it a virtual certainty that
any individual will be at a sufficient level of unconscious-
ness to resist the noxious stimuli which could occur from
the application of the second and third drugs.” App. 77.
Indeed, it found that a 500-milligram dose alone would
likely cause death by respiratory arrest within 30 minutes
                 Cite as: 576 U. S. ____ (2015)          11

                     Opinion of the Court

or an hour.
   The Court of Appeals for the Tenth Circuit affirmed.
776 F. 3d 721. The Court of Appeals explained that our
decision in Baze requires a plaintiff challenging a lethal
injection protocol to demonstrate that the risk of severe
pain presented by an execution protocol is substantial
“ ‘when compared to the known and available alterna-
tives.’ ” Id., at 732 (quoting Baze, supra, at 61). And it
agreed with the District Court that petitioners had not
identified any such alternative. The Court of Appeals
added, however, that this holding was “not outcome-
determinative in this case” because petitioners additionally
failed to establish that the use of midazolam creates a
demonstrated risk of severe pain. 776 F. 3d, at 732. The
Court of Appeals found that the District Court did not
abuse its discretion by relying on Dr. Evans’ testimony,
and it concluded that the District Court’s factual findings
about midazolam were not clearly erroneous. It also held
that alleged errors in Dr. Evans’ testimony did not render
his testimony unreliable or the District Court’s findings
clearly erroneous.
   Oklahoma executed Warner on January 15, 2015, but
we subsequently voted to grant review and then stayed
the executions of Glossip, Cole, and Grant pending the
resolution of this case. 574 U. S. ___ (2015).
                              III
   “A plaintiff seeking a preliminary injunction must estab-
lish that he is likely to succeed on the merits, that he is
likely to suffer irreparable harm in the absence of prelimi-
nary relief, that the balance of equities tips in his favor,
and that an injunction is in the public interest.” Winter v.
Natural Resources Defense Council, Inc., 555 U. S. 7, 20
(2008). The parties agree that this case turns on whether
petitioners are able to establish a likelihood of success on
the merits.
12                   GLOSSIP v. GROSS

                     Opinion of the Court

   The Eighth Amendment, made applicable to the States
through the Fourteenth Amendment, prohibits the inflic-
tion of “cruel and unusual punishments.” The controlling
opinion in Baze outlined what a prisoner must establish to
succeed on an Eighth Amendment method-of-execution
claim. Baze involved a challenge by Kentucky death row
inmates to that State’s three-drug lethal injection protocol
of sodium thiopental, pancuronium bromide, and potassium
chloride. The inmates conceded that the protocol, if
properly administered, would result in a humane and
constitutional execution because sodium thiopental would
render an inmate oblivious to any pain caused by the
second and third drugs. 553 U. S., at 49. But they argued
that there was an unacceptable risk that sodium thiopen-
tal would not be properly administered. Ibid. The in-
mates also maintained that a significant risk of harm
could be eliminated if Kentucky adopted a one-drug proto-
col and additional monitoring by trained personnel. Id., at
51.
   The controlling opinion in Baze first concluded that
prisoners cannot successfully challenge a method of execu-
tion unless they establish that the method presents a risk
that is “ ‘sure or very likely to cause serious illness and
needless suffering,’ and give rise to ‘sufficiently imminent
dangers.’ ” Id., at 50 (quoting Helling v. McKinney, 509
U. S. 25, 33, 34–35 (1993)). To prevail on such a claim,
“there must be a ‘substantial risk of serious harm,’ an
‘objectively intolerable risk of harm’ that prevents prison
officials from pleading that they were ‘subjectively blame-
less for purposes of the Eighth Amendment.’ ” 553 U. S.,
at 50 (quoting Farmer v. Brennan, 511 U. S. 825, 846, and
n. 9 (1994)). The controlling opinion also stated that
prisoners “cannot successfully challenge a State’s method
of execution merely by showing a slightly or marginally
safer alternative.” 553 U. S., at 51. Instead, prisoners
must identify an alternative that is “feasible, readily
                 Cite as: 576 U. S. ____ (2015)           13

                     Opinion of the Court

implemented, and in fact significantly reduce[s] a substan-
tial risk of severe pain.” Id., at 52.
   The controlling opinion summarized the requirements of
an Eighth Amendment method-of-execution claim as
follows: “A stay of execution may not be granted on
grounds such as those asserted here unless the condemned
prisoner establishes that the State’s lethal injection proto-
col creates a demonstrated risk of severe pain. [And] [h]e
must show that the risk is substantial when compared to
the known and available alternatives.” Id., at 61. The
preliminary injunction posture of the present case thus
requires petitioners to establish a likelihood that they can
establish both that Oklahoma’s lethal injection protocol
creates a demonstrated risk of severe pain and that the
risk is substantial when compared to the known and
available alternatives.
   The challenge in Baze failed both because the Kentucky
inmates did not show that the risks they identified were
substantial and imminent, id., at 56, and because they did
not establish the existence of a known and available alter-
native method of execution that would entail a significantly
less severe risk, id., at 57–60. Petitioners’ arguments
here fail for similar reasons. First, petitioners have not
proved that any risk posed by midazolam is substantial
when compared to known and available alternative meth-
ods of execution. Second, they have failed to establish that
the District Court committed clear error when it found
that the use of midazolam will not result in severe pain
and suffering. We address each reason in turn.
                              IV
  Our first ground for affirmance is based on petitioners’
failure to satisfy their burden of establishing that any risk
of harm was substantial when compared to a known and
available alternative method of execution.          In their
amended complaint, petitioners proffered that the State
14                        GLOSSIP v. GROSS

                          Opinion of the Court

could use sodium thiopental as part of a single-drug proto-
col. They have since suggested that it might also be con-
stitutional for Oklahoma to use pentobarbital. But the
District Court found that both sodium thiopental and
pentobarbital are now unavailable to Oklahoma’s De-
partment of Corrections. The Court of Appeals affirmed
that finding, and it is not clearly erroneous. On the con-
trary, the record shows that Oklahoma has been unable to
procure those drugs despite a good-faith effort to do so.
  Petitioners do not seriously contest this factual finding,
and they have not identified any available drug or drugs
that could be used in place of those that Oklahoma is now
unable to obtain. Nor have they shown a risk of pain so
great that other acceptable, available methods must be
used. Instead, they argue that they need not identify a
known and available method of execution that presents
less risk. But this argument is inconsistent with the
controlling opinion in Baze, 553 U. S., at 61, which im-
posed a requirement that the Court now follows.2
  Petitioners contend that the requirement to identify an
alternative method of execution contravenes our pre-Baze
decision in Hill v. McDonough, 547 U. S. 573 (2006), but
they misread that decision. The portion of the opinion in
Hill on which they rely concerned a question of civil pro-
cedure, not a substantive Eighth Amendment question. In

——————
  2 JUSTICE SOTOMAYOR’s dissent (hereinafter principal dissent), post, at
24–25, inexplicably refuses to recognize that THE CHIEF JUSTICE’s
opinion in Baze sets out the holding of the case. In Baze, the opinion of
THE CHIEF JUSTICE was joined by two other JUSTICES. JUSTICES SCALIA
and THOMAS took the broader position that a method of execution is
consistent with the Eighth Amendment unless it is deliberately de-
signed to inflict pain. 553 U. S., at 94 (THOMAS, J. concurring in judg-
ment). Thus, as explained in Marks v. United States, 430 U. S. 188,
193 (1977), THE CHIEF JUSTICE’s opinion sets out the holding of the
case. It is for this reason that petitioners base their argument on the
rule set out in that opinion. See Brief for Petitioners 25, 28.
                 Cite as: 576 U. S. ____ (2015)           15

                     Opinion of the Court

Hill, the issue was whether a challenge to a method of
execution must be brought by means of an application for
a writ of habeas corpus or a civil action under §1983. Id.,
at 576. We held that a method-of-execution claim must be
brought under §1983 because such a claim does not attack
the validity of the prisoner’s conviction or death sentence.
Id., at 579–580. The United States as amicus curiae
argued that we should adopt a special pleading require-
ment to stop inmates from using §1983 actions to attack,
not just a particular means of execution, but the death
penalty itself. To achieve this end, the United States
proposed that an inmate asserting a method-of-execution
claim should be required to plead an acceptable alterna-
tive method of execution. Id., at 582. We rejected that
argument because “[s]pecific pleading requirements are
mandated by the Federal Rules of Civil Procedure, and
not, as a general rule, through case-by-case determina-
tions of the federal courts.” Ibid. Hill thus held that
§1983 alone does not impose a heightened pleading re-
quirement. Baze, on the other hand, addressed the sub-
stantive elements of an Eighth Amendment method-of-
execution claim, and it made clear that the Eighth
Amendment requires a prisoner to plead and prove a
known and available alternative. Because petitioners
failed to do this, the District Court properly held that they
did not establish a likelihood of success on their Eighth
Amendment claim.
   Readers can judge for themselves how much distance
there is between the principal dissent’s argument against
requiring prisoners to identify an alternative and the
view, now announced by JUSTICES BREYER and GINSBURG,
that the death penalty is categorically unconstitutional.
Post, p. ___ (BREYER, J., dissenting). The principal dissent
goes out of its way to suggest that a State would violate
the Eighth Amendment if it used one of the methods of
execution employed before the advent of lethal injection.
16                   GLOSSIP v. GROSS

                     Opinion of the Court

Post, at 30–31. And the principal dissent makes this
suggestion even though the Court held in Wilkerson that
this method (the firing squad) is constitutional and even
though, in the words of the principal dissent, “there is
some reason to think that it is relatively quick and pain-
less.” Post, at 30. Tellingly silent about the methods of
execution most commonly used before States switched to
lethal injection (the electric chair and gas chamber), the
principal dissent implies that it would be unconstitutional
to use a method that “could be seen as a devolution to a
more primitive era.” Ibid. If States cannot return to any
of the “more primitive” methods used in the past and if no
drug that meets with the principal dissent’s approval is
available for use in carrying out a death sentence, the
logical conclusion is clear. But we have time and again
reaffirmed that capital punishment is not per se unconsti-
tutional. See, e.g., Baze, 553 U. S., at 47; id., at 87–88
(SCALIA, J., concurring in judgment); Gregg, 428 U. S., at
187 (joint opinion of Stewart, Powell, and Stevens, JJ.);
id., at 226 (White, J., concurring in judgment); Resweber,
329 U. S., at 464; In re Kemmler, 136 U. S., at 447; Wilker-
son, 99 U. S., at 134–135. We decline to effectively over-
rule these decisions.
                            V
  We also affirm for a second reason: The District Court
did not commit clear error when it found that midazolam
is highly likely to render a person unable to feel pain
during an execution. We emphasize four points at the
outset of our analysis.
  First, we review the District Court’s factual findings
under the deferential “clear error” standard. This stand-
ard does not entitle us to overturn a finding “simply be-
cause [we are] convinced that [we] would have decided the
case differently.” Anderson v. Bessemer City, 470 U. S.
564, 573 (1985).
                 Cite as: 576 U. S. ____ (2015)          17

                     Opinion of the Court

   Second, petitioners bear the burden of persuasion on
this issue. Baze, supra, at 41. Although petitioners
expend great effort attacking peripheral aspects of Dr.
Evans’ testimony, they make little attempt to prove what
is critical, i.e., that the evidence they presented to the
District Court establishes that the use of midazolam is
sure or very likely to result in needless suffering.
   Third, numerous courts have concluded that the use of
midazolam as the first drug in a three-drug protocol is
likely to render an inmate insensate to pain that might
result from administration of the paralytic agent and
potassium chloride. See, e.g., 776 F. 3d 721 (case below
affirming the District Court); Chavez v. Florida SP War-
den, 742 F. 3d 1267 (affirming the District Court); Banks
v. State, 150 So. 3d 797 (Fla. 2014) (affirming the lower
court); Howell v. State, 133 So. 3d 511 (Fla. 2014) (same);
Muhammad v. State, 132 So. 3d 176 (Fla. 2013) (same).
(It is noteworthy that one or both of the two key witnesses
in this case—Dr. Lubarsky for petitioners and Dr. Evans
for respondents—were witnesses in the Chavez, Howell,
and Muhammad cases.) “Where an intermediate court
reviews, and affirms, a trial court’s factual findings, this
Court will not ‘lightly overturn’ the concurrent findings of
the two lower courts.” Easley v. Cromartie, 532 U. S. 234,
242 (2001). Our review is even more deferential where, as
here, multiple trial courts have reached the same finding,
and multiple appellate courts have affirmed those find-
ings. Cf. Exxon Co., U. S. A. v. Sofec, Inc., 517 U. S. 830,
841 (1996) (explaining that this Court “ ‘cannot undertake
to review concurrent findings of fact by two courts below
in the absence of a very obvious and exceptional showing
of error’ ” (quoting Graver Tank & Mfg. Co. v. Linde Air
Products Co., 336 U. S. 271, 275 (1949))).
   Fourth, challenges to lethal injection protocols test the
boundaries of the authority and competency of federal
courts. Although we must invalidate a lethal injection
18                        GLOSSIP v. GROSS

                          Opinion of the Court

protocol if it violates the Eighth Amendment, federal
courts should not “embroil [themselves] in ongoing scien-
tific controversies beyond their expertise.” Baze, supra, at
51. Accordingly, an inmate challenging a protocol bears
the burden to show, based on evidence presented to the
court, that there is a substantial risk of severe pain.
                              A
  Petitioners attack the District Court’s findings of fact on
two main grounds.3 First, they argue that even if midazo-
lam is powerful enough to induce unconsciousness, it is too
weak to maintain unconsciousness and insensitivity to
pain once the second and third drugs are administered.
Second, while conceding that the 500-milligram dose of
midazolam is much higher than the normal therapeutic
dose, they contend that this fact is irrelevant because
midazolam has a “ceiling effect”—that is, at a certain
point, an increase in the dose administered will not have
any greater effect on the inmate. Neither argument
succeeds.
  The District Court found that midazolam is capable of
placing a person “at a sufficient level of unconsciousness to
resist the noxious stimuli which could occur from the

——————
   3 Drs. Lubarsky and Sasich, petitioners’ key witnesses, both testified

that midazolam is inappropriate for a third reason, namely, that it
creates a risk of “paradoxical reactions” such as agitation, hyperactiv-
ity, and combativeness. App. 175 (expert report of Dr. Lubarsky); id., at
242, 244 (expert report of Dr. Sasich). The District Court found, how-
ever, that the frequency with which a paradoxical reaction occurs “is
speculative” and that the risk “occurs with the highest frequency in low
therapeutic doses.” Id., at 78. Indeed, Dr. Sasich conceded that the
incidence or risk of paradoxical reactions with midazolam “is unknown”
and that reports estimate the risk to vary only “from 1% to above 10%.”
Id., at 244. Moreover, the mere fact that a method of execution might
result in some unintended side effects does not amount to an Eighth
Amendment violation. “[T]he Constitution does not demand the avoid-
ance of all risk of pain.” Baze, 553 U. S., at 47 (plurality opinion).
                 Cite as: 576 U. S. ____ (2015)           19

                     Opinion of the Court

application of the second and third drugs.” App. 77. This
conclusion was not clearly erroneous. Respondents’ ex-
pert, Dr. Evans, testified that the proper administration of
a 500-milligram dose of midazolam would make it “a
virtual certainty” that any individual would be “at a suffi-
cient level of unconsciousness to resist the noxious stimuli
which could occur from application of the 2nd and 3rd
drugs” used in the Oklahoma protocol. Id., at 302; see also
id., at 322. And petitioners’ experts acknowledged that
they had no contrary scientific proof. See id., at 243–244
(Dr. Sasich stating that the ability of midazolam to render
a person insensate to the second and third drugs “has not
been subjected to scientific testing”); id., at 176 (Dr.
Lubarksy stating that “there is no scientific literature
addressing the use of midazolam as a manner to adminis-
ter lethal injections in humans”).
  In an effort to explain this dearth of evidence, Dr. Sasich
testified that “[i]t’s not my responsibility or the [Food and
Drug Administration’s] responsibility to prove that the
drug doesn’t work or is not safe.” Tr. of Preliminary In-
junction Hearing 357 (Tr.). Instead, he stated, “it’s the
responsibility of the proponent to show that the drug is
safe and effective.” Ibid. Dr. Sasich confused the stand-
ard imposed on a drug manufacturer seeking approval of a
therapeutic drug with the standard that must be borne by
a party challenging a State’s lethal injection protocol.
When a method of execution is authorized under state law,
a party contending that this method violates the Eighth
Amendment bears the burden of showing that the method
creates an unacceptable risk of pain. Here, petitioners’
own experts effectively conceded that they lacked evidence
to prove their case beyond dispute.
  Petitioners attempt to avoid this deficiency by criticizing
respondents’ expert. They argue that the District Court
should not have credited Dr. Evans’ testimony because he
admitted that his findings were based on “ ‘extrapo-
20                       GLOSSIP v. GROSS

                         Opinion of the Court

lat[ions]’ ” from studies done about much lower therapeutic
doses of midazolam. See Brief for Petitioners 34 (citing Tr.
667–668; emphasis deleted). But because a 500-milligram
dose is never administered for a therapeutic purpose,
extrapolation was reasonable. And the conclusions of
petitioners’ experts were also based on extrapolations and
assumptions. For example, Dr. Lubarsky relied on “ex-
trapolation of the ceiling effect data.” App. 177.
   Based on the evidence that the parties presented to the
District Court, we must affirm. Testimony from both sides
supports the District Court’s conclusion that midazolam
can render a person insensate to pain. Dr. Evans testified
that although midazolam is not an analgesic, it can none-
theless “render the person unconscious and ‘insen-
sate’ during the remainder of the procedure.” Id., at 294.
In his discussion about the ceiling effect, Dr. Sasich agreed
that as the dose of midazolam increases, it is “expected to
produce sedation, amnesia, and finally lack of response to
stimuli such as pain (unconsciousness).” Id., at 243.
Petitioners argue that midazolam is not powerful enough
to keep a person insensate to pain after the administration
of the second and third drugs, but Dr. Evans presented
creditable testimony to the contrary. See, e.g., Tr. 661
(testifying that a 500-milligram dose of midazolam will
induce a coma).4 Indeed, low doses of midazolam are
sufficient to induce unconsciousness and are even some-


——————
   4 The principal dissent misunderstands the record when it bizarrely

suggests that midazolam is about as dangerous as a peanut. Post, at
15. Dr. Evans and Dr. Lubarsky agreed that midazolam has caused
fatalities in doses as low as 0.04 to 0.07 milligrams per kilogram. App.
217, 294. Even if death from such low doses is a “rare, unfortunate side
effec[t],” post, at 15, the District Court found that a massive 500-
milligram dose—many times higher than the lowest dose reported to
have produced death—will likely cause death in under an hour. App.
76–77.
                    Cite as: 576 U. S. ____ (2015)                 21

                        Opinion of the Court

times used as the sole relevant drug in certain medical
procedures. Dr. Sasich conceded, for example, that mid-
azolam might be used for medical procedures like colonos-
copies and gastroscopies. App. 267–268; see also Brief for
Respondents 6–8.5
  Petitioners emphasize that midazolam is not recom-
mended or approved for use as the sole anesthetic during
painful surgery, but there are two reasons why this is not
dispositive. First, as the District Court found, the 500-
milligram dose at issue here “is many times higher than a
normal therapeutic dose of midazolam.” App. 76. The
effect of a small dose of midazolam has minimal probative
value about the effect of a 500-milligram dose. Second, the
fact that a low dose of midazolam is not the best drug for
maintaining unconsciousness during surgery says little
about whether a 500-milligram dose of midazolam is
constitutionally adequate for purposes of conducting an
execution. We recognized this point in Baze, where we
concluded that although the medical standard of care
might require the use of a blood pressure cuff and an
electrocardiogram during surgeries, this does not mean
those procedures are required for an execution to pass
Eighth Amendment scrutiny. 553 U. S., at 60.
  Oklahoma has also adopted important safeguards to
ensure that midazolam is properly administered. The

——————
  5 Petitioners’experts also declined to testify that a 500-milligram
dose of midazolam is always insufficient to place a person in a coma
and render him insensate to pain. Dr. Lubarsky argued only that the
500-milligram dose cannot “reliably” produce a coma. Id., 228. And
when Dr. Sasich was asked whether he could say to a reasonable
degree of certainty that a 500-milligram dose of midazolam would not
render someone unconscious, he replied that he could not. Id., at 271–
272. A product label for midazolam that Dr. Sasich attached to his
expert report also acknowledged that an overdose of midazolam can
cause a coma. See Expert Report of Larry D. Sasich, in No. 14–6244
(CA10), p. 34.
22                   GLOSSIP v. GROSS

                     Opinion of the Court

District Court emphasized three requirements in particu-
lar: The execution team must secure both a primary and
backup IV access site, it must confirm the viability of the
IV sites, and it must continuously monitor the offender’s
level of consciousness. The District Court did not commit
clear error in concluding that these safeguards help to
minimize any risk that might occur in the event that
midazolam does not operate as intended. Indeed, we
concluded in Baze that many of the safeguards that Okla-
homa employs—including the establishment of a primary
and backup IV and the presence of personnel to monitor
an inmate—help in significantly reducing the risk that an
execution protocol will violate the Eighth Amendment.
Id., at 55–56. And many other safeguards that Oklahoma
has adopted mirror those that the dissent in Baze com-
plained were absent from Kentucky’s protocol in that case.
For example, the dissent argued that because a conscious-
ness check before injection of the second drug “can reduce
a risk of dreadful pain,” Kentucky’s failure to include that
step in its procedure was unconstitutional. Id., at 119
(opinion of GINSBURG, J.). The dissent also complained
that Kentucky did not monitor the effectiveness of the first
drug or pause between injection of the first and second
drugs. Id., at 120–121. Oklahoma has accommodated
each of those concerns.
                              B
   Petitioners assert that midazolam’s “ceiling effect”
undermines the District Court’s finding about the effec-
tiveness of the huge dose administered in the Oklahoma
protocol. Petitioners argue that midazolam has a “ceiling”
above which any increase in dosage produces no effect. As
a result, they maintain, it is wrong to assume that a 500-
milligram dose has a much greater effect than a therapeu-
tic dose of about 5 milligrams. But the mere fact that
midazolam has such a ceiling cannot be dispositive. Dr.
                  Cite as: 576 U. S. ____ (2015)           23

                      Opinion of the Court

Sasich testified that “all drugs essentially have a ceiling
effect.” Tr. 343. The relevant question here is whether
midazolam’s ceiling effect occurs below the level of a 500-
milligram dose and at a point at which the drug does not
have the effect of rendering a person insensate to pain
caused by the second and third drugs.
   Petitioners provided little probative evidence on this
point, and the speculative evidence that they did present
to the District Court does not come close to establishing
that its factual findings were clearly erroneous.
Dr. Sasich stated in his expert report that the literature
“indicates” that midazolam has a ceiling effect, but he
conceded that he “was unable to determine the midazolam
dose for a ceiling effect on unconsciousness because there
is no literature in which such testing has been done.” App.
243–244. Dr. Lubarsky’s report was similar, id., at 171–
172, and the testimony of petitioners’ experts at the hear-
ing was no more compelling. Dr. Sasich frankly admitted
that he did a “search to try and determine at what dose of
midazolam you would get a ceiling effect,” but concluded:
“I could not find one.” Tr. 344. The closest petitioners
came was Dr. Lubarsky’s suggestion that the ceiling effect
occurs “[p]robably after about . . . 40 to 50 milligrams,” but
he added that he had not actually done the relevant calcu-
lations, and he admitted: “I can’t tell you right now” at
what dose the ceiling effect occurs. App. 225. We cannot
conclude that the District Court committed clear error in
declining to find, based on such speculative evidence, that
the ceiling effect negates midazolam’s ability to render an
inmate insensate to pain caused by the second and third
drugs in the protocol.
   The principal dissent discusses the ceiling effect at
length, but it studiously avoids suggesting that petitioners
presented probative evidence about the dose at which the
ceiling effect occurs or about whether the effect occurs
before a person becomes insensate to pain. The principal
24                       GLOSSIP v. GROSS

                         Opinion of the Court

dissent avoids these critical issues by suggesting that such
evidence is “irrelevant if there is no dose at which the drug
can . . . render a person ‘insensate to pain.’ ” Post, at 17.
But the District Court heard evidence that the drug can
render a person insensate to pain, and not just from Dr.
Evans: Dr. Sasich (one of petitioners’ own experts) testi-
fied that higher doses of midazolam are “expected to pro-
duce . . . lack of response to stimuli such as pain.” App.
243.6
   In their brief, petitioners attempt to deflect attention
from their failure of proof regarding midazolam’s ceiling
effect by criticizing Dr. Evans’ testimony. But it was
petitioners’ burden to establish that midazolam’s ceiling
occurred at a dosage below the massive 500-milligram
dose employed in the Oklahoma protocol and at a point at
which the drug failed to render the recipient insensate to
pain. They did not meet that burden, and their criticisms
do not undermine Dr. Evans’ central point, which the
District Court credited, that a properly administered 500-
milligram dose of midazolam will render the recipient
unable to feel pain.
   One of petitioners’ criticisms of Dr. Evans’ testimony is
little more than a quibble about the wording chosen by Dr.
Evans at one point in his oral testimony. Petitioners’
expert, Dr. Lubarsky, stated in his report that midazolam
“increases effective binding of [gamma-aminobutyric acid
(GABA)] to its receptor to induce unconsciousness.”7 App.
——————
  6 The principal dissent emphasizes Dr. Lubarsky’s supposedly contra-

ry testimony, but the District Court was entitled to credit Dr. Evans
(and Dr. Sasich) instead of Dr. Lubarsky on this point. And the District
Court had strong reasons not to credit Dr. Lubarsky, who even argued
that a protocol that includes sodium thiopental is “constructed to
produce egregious harm and suffering.” App. 227.
  7 GABA is “an amino acid that functions as an inhibitory neuro-

transmitter in the brain and spinal cord.” Mosby’s Medical Dictionary
                      Cite as: 576 U. S. ____ (2015)      25

                          Opinion of the Court

172. Dr. Evans’ report provided a similar explanation of
the way in which midazolam works, see id., at 293–294,
and Dr. Lubarsky did not dispute the accuracy of that
explanation when he testified at the hearing. Petitioners
contend, however, that Dr. Evans erred when he said at
the hearing that “[m]idazolam attaches to GABA recep-
tors, inhibiting GABA.” Id., at 312 (emphasis added).
Petitioners contend that this statement was incorrect
because “far from inhibiting GABA, midazolam facilitates
its binding to GABA receptors.” Brief for Petitioners 38.
   In making this argument, petitioners are simply quar-
relling with the words that Dr. Evans used during oral
testimony in an effort to explain how midazolam works in
terms understandable to a layman. Petitioners do not
suggest that the discussion of midazolam in Dr. Evans’
expert report was inaccurate, and as for Dr. Evans’ pass-
ing use of the term “inhibiting,” Dr. Lubarksy’s own expert
report states that GABA’s “inhibition of brain activity is
accentuated by midazolam.” App. 232 (emphasis added).
Dr. Evans’ oral use of the word “inhibiting”—particularly
in light of his written testimony—does not invalidate the
District Court’s decision to rely on his testimony.
   Petitioners also point to an apparent conflict between
Dr. Evans’ testimony and a declaration by Dr. Lubarsky
(submitted after the District Court ruled) regarding the
biological process that produces midazolam’s ceiling effect.
But even if Dr. Lubarsky’s declaration is correct, it is
largely beside the point. What matters for present pur-
poses is the dosage at which the ceiling effect kicks in, not
the biological process that produces the effect. And Dr.
Lubarsky’s declaration does not render the District Court’s
findings clearly erroneous with respect to that critical
issue.

——————
782 (7th ed. 2006).
26                   GLOSSIP v. GROSS

                     Opinion of the Court

                              C
   Petitioners’ remaining arguments about midazolam all
lack merit. First, we are not persuaded by petitioners’
argument that Dr. Evans’ testimony should have been
rejected because of some of the sources listed in his report.
Petitioners criticize two of the “selected references” that
Dr. Evans cited in his expert report: the Web site
drugs.com and a material safety data sheet (MSDS) about
midazolam. Petitioners’ argument is more of a Daubert
challenge to Dr. Evans’ testimony than an argument that
the District Court’s findings were clearly erroneous. The
District Court concluded that Dr. Evans was “well-
qualified to give the expert testimony that he gave” and
that “his testimony was the product of reliable principles
and methods reliably applied to the facts of this case.”
App. 75–76. To the extent that the reliability of Dr.
Evans’ testimony is even before us, the District Court’s con-
clusion that his testimony was based on reliable sources is
reviewed under the deferential “abuse-of-discretion”
standard. General Elec. Co. v. Joiner, 522 U. S. 136, 142–
143 (1997). Dr. Evans relied on multiple sources and his
own expertise, and his testimony may not be disqualified
simply because one source (drugs.com) warns that it “ ‘is
not intended for medical advice’ ” and another (the MSDS)
states that its information is provided “ ‘without any war-
ranty, express or implied, regarding its correctness.’ ”
Brief for Petitioners 36. Medical journals that both par-
ties rely upon typically contain similar disclaimers. See,
e.g., Anesthesiology, Terms and Conditions of Use, online
at       http://anesthesiology.pubs.asahq.org/ss/terms.aspx
(“None of the information on this Site shall be used to
diagnose or treat any health problem or disease”). Dr.
Lubarsky—petitioners’ own expert—relied on an MSDS to
argue that midazolam has a ceiling effect. And petitioners
do not identify any incorrect statements from drugs.com
on which Dr. Evans relied. In fact, although Dr. Sasich
                  Cite as: 576 U. S. ____ (2015)            27

                      Opinion of the Court

submitted a declaration to the Court of Appeals criticizing
Dr. Evans’ reference to drugs.com, that declaration does
not identify a single fact from that site’s discussion of
midazolam that was materially inaccurate.
   Second, petitioners argue that Dr. Evans’ expert report
contained a mathematical error, but we find this argu-
ment insignificant. Dr. Evans stated in his expert report
that the lowest dose of midazolam resulting in human
deaths, according to an MSDS, is 0.071 mg/kg delivered
intravenously. App. 294. Dr. Lubarsky agreed with this
statement. Specifically, he testified that fatalities have
occurred in doses ranging from 0.04 to 0.07 mg/kg, and he
stated that Dr. Evans’ testimony to that effect was “a true
statement” (though he added those fatalities occurred
among the elderly). Id., at 217. We do not understand
petitioners to dispute the testimony of Dr. Evans and their
own expert that 0.071 mg/kg is a potentially fatal dose of
midazolam. Instead, they make much of the fact that the
MSDS attached to Dr. Evans’ report apparently contained
a typographical error and reported the lowest toxic dose as
71 mg/kg. That Dr. Evans did not repeat that incorrect
figure but instead reported the correct dose supports
rather than undermines his testimony. In any event, the
alleged error in the MSDS is irrelevant because the Dis-
trict Court expressly stated that it did not rely on the
figure in the MSDS. See id., at 75.
   Third, petitioners argue that there is no consensus
among the States regarding midazolam’s efficacy because
only four States (Oklahoma, Arizona, Florida, and Ohio)
have used midazolam as part of an execution. Petitioners
rely on the plurality’s statement in Baze that “it is difficult
to regard a practice as ‘objectively intolerable’ when it is in
fact widely tolerated,” and the plurality’s emphasis on the
fact that 36 States had adopted lethal injection and 30
States used the particular three-drug protocol at issue in
that case. 553 U. S., at 53. But while the near-universal
28                        GLOSSIP v. GROSS

                          Opinion of the Court

use of the particular protocol at issue in Baze supported
our conclusion that this protocol did not violate the Eighth
Amendment, we did not say that the converse was true,
i.e., that other protocols or methods of execution are of
doubtful constitutionality. That argument, if accepted,
would hamper the adoption of new and potentially more
humane methods of execution and would prevent States
from adapting to changes in the availability of suitable
drugs.
   Fourth, petitioners argue that difficulties with Oklaho-
ma’s execution of Lockett and Arizona’s July 2014 execu-
tion of Joseph Wood establish that midazolam is sure or
very likely to cause serious pain. We are not persuaded.
Aside from the Lockett execution, 12 other executions
have been conducted using the three-drug protocol at issue
here, and those appear to have been conducted without
any significant problems. See Brief for Respondents 32;
Brief for State of Florida as Amicus Curiae 1. Moreover,
Lockett was administered only 100 milligrams of midazo-
lam, and Oklahoma’s investigation into that execution
concluded that the difficulties were due primarily to the
execution team’s inability to obtain an IV access site. And
the Wood execution did not involve the protocol at issue
here. Wood did not receive a single dose of 500 milligrams
of midazolam; instead, he received fifteen 50-milligram
doses over the span of two hours.8 Brief for Respondents
——————
  8 The  principal dissent emphasizes Dr. Lubarsky’s testimony that it is
irrelevant that Wood was administered the drug over a 2-hour period.
Post, at 20. But Dr. Evans disagreed and testified that if a 750-
milligram dose “was spread out over a long period of time,” such as one
hour (i.e., half the time at issue in the Wood execution), the drug might
not be as effective as if it were administered all at once. Tr. 667. The
principal dissent states that this “pronouncement was entirely unsup-
ported,” post, at 20, n. 6, but it was supported by Dr. Evans’ expertise
and decades of experience. And it would be unusual for an expert
testifying on the stand to punctuate each sentence with citation to a
                     Cite as: 576 U. S. ____ (2015)                    29

                          Opinion of the Court

12, n. 9. And Arizona used a different two-drug protocol
that paired midazolam with hydromorphone, a drug that
is not at issue in this case. Ibid. When all of the circum-
stances are considered, the Lockett and Wood executions
have little probative value for present purposes.
   Finally, we find it appropriate to respond to the princi-
pal dissent’s groundless suggestion that our decision is
tantamount to allowing prisoners to be “drawn and quar-
tered, slowly tortured to death, or actually burned at the
stake.” Post, at 28. That is simply not true, and the prin-
cipal dissent’s resort to this outlandish rhetoric reveals the
weakness of its legal arguments.
                              VI
  For these reasons, the judgment of the Court of Appeals
for the Tenth Circuit is affirmed.
                                          It is so ordered.




——————
medical journal.
  After the Wood execution, Arizona commissioned an independent
assessment of its execution protocol and the Wood execution. According
to that report, the IV team leader, medical examiner, and an independ-
ent physician all agreed that the dosage of midazolam “would result in
heavy sedation.” Ariz. Dept. of Corrections, Assessment and Review of
the Ariz. Dept. of Corrections Execution Protocols 46, 48 (Dec. 15,
2014), online at https://corrections.az.gov/sites/default/files/documents/
PDFs/arizona_final_report_12_15_14_w_cover.pdf.          And far from
blaming midazolam for the Wood execution, the report recommended
that Arizona replace its two-drug protocol with Oklahoma’s three-drug
protocol that includes a 500-milligram dose of midazolam as the first
drug. Id., at 49.
                 Cite as: 576 U. S. ____ (2015)            1

                     SCALIA, J., concurring

SUPREME COURT OF THE UNITED STATES
                         _________________

                         No. 14–7955
                         _________________


    RICHARD E. GLOSSIP, ET AL., PETITIONERS v.


             KEVIN J. GROSS, ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE TENTH CIRCUIT


                        [June 29, 2015] 


   JUSTICE SCALIA, with whom JUSTICE THOMAS joins,
concurring.
   I join the opinion of the Court, and write to respond to
JUSTICE BREYER’s plea for judicial abolition of the death
penalty.
   Welcome to Groundhog Day. The scene is familiar:
Petitioners, sentenced to die for the crimes they committed
(including, in the case of one petitioner since put to death,
raping and murdering an 11–month-old baby), come before
this Court asking us to nullify their sentences as “cruel
and unusual” under the Eighth Amendment. They rely on
this provision because it is the only provision they can rely
on. They were charged by a sovereign State with murder.
They were afforded counsel and tried before a jury of their
peers—tried twice, once to determine whether they were
guilty and once to determine whether death was the ap-
propriate sentence. They were duly convicted and sen-
tenced. They were granted the right to appeal and to seek
postconviction relief, first in state and then in federal
court. And now, acknowledging that their convictions are
unassailable, they ask us for clemency, as though clemency
were ours to give.
   The response is also familiar: A vocal minority of the
Court, waving over their heads a ream of the most recent
abolitionist studies (a superabundant genre) as though
2                    GLOSSIP v. GROSS

                     SCALIA, J., concurring

they have discovered the lost folios of Shakespeare, insist
that now, at long last, the death penalty must be abolished
for good. Mind you, not once in the history of the Ameri-
can Republic has this Court ever suggested the death
penalty is categorically impermissible. The reason is
obvious: It is impossible to hold unconstitutional that
which the Constitution explicitly contemplates. The Fifth
Amendment provides that “[n]o person shall be held to
answer for a capital . . . crime, unless on a presentment or
indictment of a Grand Jury,” and that no person shall be
“deprived of life . . . without due process of law.” Never-
theless, today JUSTICE BREYER takes on the role of the
abolitionists in this long-running drama, arguing that the
text of the Constitution and two centuries of history must
yield to his “20 years of experience on this Court,” and
inviting full briefing on the continued permissibility of
capital punishment, post, at 2 (dissenting opinion).
  Historically, the Eighth Amendment was understood to
bar only those punishments that added “ ‘terror, pain, or
disgrace’ ” to an otherwise permissible capital sentence.
Baze v. Rees, 553 U. S. 35, 96 (2008) (THOMAS, J., concur-
ring in judgment). Rather than bother with this troubling
detail, JUSTICE BREYER elects to contort the constitutional
text. Redefining “cruel” to mean “unreliable,” “arbitrary,”
or causing “excessive delays,” and “unusual” to include a
“decline in use,” he proceeds to offer up a white paper
devoid of any meaningful legal argument.
  Even accepting JUSTICE BREYER’s rewriting of the
Eighth Amendment, his argument is full of internal con-
tradictions and (it must be said) gobbledy-gook. He says
that the death penalty is cruel because it is unreliable; but
it is convictions, not punishments, that are unreliable.
Moreover, the “pressure on police, prosecutors, and jurors
to secure a conviction,” which he claims increases the risk
of wrongful convictions in capital cases, flows from the
nature of the crime, not the punishment that follows its
                 Cite as: 576 U. S. ____ (2015)            3

                     SCALIA, J., concurring

commission. Post, at 6. JUSTICE BREYER acknowledges as
much: “[T]he crimes at issue in capital cases are typically
horrendous murders, and thus accompanied by intense
community pressure.” Ibid. That same pressure would
exist, and the same risk of wrongful convictions, if horren-
dous death-penalty cases were converted into equally
horrendous life-without-parole cases. The reality is that
any innocent defendant is infinitely better off appealing a
death sentence than a sentence of life imprisonment.
(Which, again, JUSTICE BREYER acknowledges: “[C]ourts
(or State Governors) are 130 times more likely to exoner-
ate a defendant where a death sentence is at issue,” post,
at 5.) The capital convict will obtain endless legal assis-
tance from the abolition lobby (and legal favoritism from
abolitionist judges), while the lifer languishes unnoticed
behind bars.
   JUSTICE BREYER next says that the death penalty is
cruel because it is arbitrary. To prove this point, he points
to a study of 205 cases that “measured the ‘egregiousness’
of the murderer’s conduct” with “a system of metrics,” and
then “compared the egregiousness of the conduct of the 9
defendants sentenced to death with the egregiousness of
the conduct of defendants in the remaining 196 cases [who
were not sentenced to death],” post, at 10–11. If only
Aristotle, Aquinas, and Hume knew that moral philosophy
could be so neatly distilled into a pocket-sized, vade me-
cum “system of metrics.” Of course it cannot: Egregious-
ness is a moral judgment susceptible of few hard-and-fast
rules. More importantly, egregiousness of the crime is
only one of several factors that render a punishment con-
dign—culpability, rehabilitative potential, and the need
for deterrence also are relevant. That is why this Court
has required an individualized consideration of all miti-
gating circumstances, rather than formulaic application of
some egregiousness test.
   It is because these questions are contextual and admit of
4                     GLOSSIP v. GROSS

                     SCALIA, J., concurring

no easy answers that we rely on juries to make judgments
about the people and crimes before them. The fact that
these judgments may vary across cases is an inevitable
consequence of the jury trial, that cornerstone of Anglo-
American judicial procedure. But when a punishment is
authorized by law—if you kill you are subject to death—
the fact that some defendants receive mercy from their
jury no more renders the underlying punishment “cruel”
than does the fact that some guilty individuals are never
apprehended, are never tried, are acquitted, or are
pardoned.
   JUSTICE BREYER’s third reason that the death penalty is
cruel is that it entails delay, thereby (1) subjecting in-
mates to long periods on death row and (2) undermining
the penological justifications of the death penalty. The
first point is nonsense. Life without parole is an even
lengthier period than the wait on death row; and if the
objection is that death row is a more confining environ-
ment, the solution should be modifying the environment
rather than abolishing the death penalty. As for the
argument that delay undermines the penological ration-
ales for the death penalty: In insisting that “the major
alternative to capital punishment—namely, life in prison
without possibility of parole—also incapacitates,” post, at
24, JUSTICE BREYER apparently forgets that one of the
plaintiffs in this very case was already in prison when he
committed the murder that landed him on death row.
JUSTICE BREYER further asserts that “whatever interest in
retribution might be served by the death penalty as cur-
rently administered, that interest can be served almost as
well by a sentence of life in prison without parole,” post, at
27. My goodness. If he thinks the death penalty not much
more harsh (and hence not much more retributive), why is
he so keen to get rid of it? With all due respect, whether
the death penalty and life imprisonment constitute more-
or-less equivalent retribution is a question far above the
                 Cite as: 576 U. S. ____ (2015)            5

                     SCALIA, J., concurring

judiciary’s pay grade. Perhaps JUSTICE BREYER is more
forgiving—or more enlightened—than those who, like
Kant, believe that death is the only just punishment for
taking a life. I would not presume to tell parents whose
life has been forever altered by the brutal murder of a
child that life imprisonment is punishment enough.
   And finally, JUSTICE BREYER speculates that it does not
“seem likely” that the death penalty has a “significant”
deterrent effect. Post, at 25. It seems very likely to me,
and there are statistical studies that say so. See, e.g.,
Zimmerman, State Executions, Deterrence, and the Inci-
dence of Murder, 7 J. Applied Econ. 163, 166 (2004) (“[I]t
is estimated that each state execution deters approximately
fourteen murders per year on average”); Dezhbakhsh,
Rubin, & Shepherd, Does Capital Punishment Have a
Deterrent Effect? New Evidence from Postmoratorium
Panel Data, 5 Am. L. & Econ. Rev. 344 (2003) (“[E]ach
execution results, on average, in eighteen fewer murders”
per year); Sunstein & Vermeule, Is Capital Punishment
Morally Required? Acts, Omissions, and Life-Life
Tradeoffs, 58 Stan. L. Rev. 703, 713 (2005) (“All in all, the
recent evidence of a deterrent effect from capital punish-
ment seems impressive, especially in light of its ‘apparent
power and unanimity’ ”). But we federal judges live in a
world apart from the vast majority of Americans. After
work, we retire to homes in placid suburbia or to high-rise
co-ops with guards at the door. We are not confronted
with the threat of violence that is ever present in many
Americans’ everyday lives. The suggestion that the in-
cremental deterrent effect of capital punishment does not
seem “significant” reflects, it seems to me, a let-them-eat-
cake obliviousness to the needs of others. Let the People
decide how much incremental deterrence is appropriate.
   Of course, this delay is a problem of the Court’s own
making. As JUSTICE BREYER concedes, for more than 160
years, capital sentences were carried out in an average of
6                    GLOSSIP v. GROSS

                     SCALIA, J., concurring

two years or less. Post, at 18. But by 2014, he tells us, it
took an average of 18 years to carry out a death sentence.
Id., at 19. What happened in the intervening years?
Nothing other than the proliferation of labyrinthine re-
strictions on capital punishment, promulgated by this
Court under an interpretation of the Eighth Amendment
that empowered it to divine “the evolving standards of
decency that mark the progress of a maturing society,”
Trop v. Dulles, 356 U. S. 86, 101 (1958) (plurality opin-
ion)—a task for which we are eminently ill suited. Indeed,
for the past two decades, JUSTICE BREYER has been the
Drum Major in this parade. His invocation of the result-
ant delay as grounds for abolishing the death penalty calls
to mind the man sentenced to death for killing his parents,
who pleads for mercy on the ground that he is an orphan.
Amplifying the surrealism of his argument, JUSTICE
BREYER uses the fact that many States have abandoned
capital punishment—have abandoned it precisely because
of the costs those suspect decisions have imposed—to
conclude that it is now “unusual.” Post, at 33–39. (A
caution to the reader: Do not use the creative arithmetic
that JUSTICE BREYER employs in counting the number of
States that use the death penalty when you prepare your
next tax return; outside the world of our Eighth Amend-
ment abolitionist-inspired jurisprudence, it will be regarded
as more misrepresentation than math.)
   If we were to travel down the path that JUSTICE BREYER
sets out for us and once again consider the constitutionality
of the death penalty, I would ask that counsel also brief
whether our cases that have abandoned the historical
understanding of the Eighth Amendment, beginning with
Trop, should be overruled. That case has caused more
mischief to our jurisprudence, to our federal system, and
to our society than any other that comes to mind. JUSTICE
BREYER’s dissent is the living refutation of Trop’s assump-
tion that this Court has the capacity to recognize “evolving
                 Cite as: 576 U. S. ____ (2015)           7

                     SCALIA, J., concurring

standards of decency.” Time and again, the People have
voted to exact the death penalty as punishment for the
most serious of crimes. Time and again, this Court has
upheld that decision. And time and again, a vocal minor-
ity of this Court has insisted that things have “changed
radically,” post, at 2, and has sought to replace the judg-
ments of the People with their own standards of decency.
   Capital punishment presents moral questions that
philosophers, theologians, and statesmen have grappled
with for millennia. The Framers of our Constitution
disagreed bitterly on the matter. For that reason, they
handled it the same way they handled many other contro-
versial issues: they left it to the People to decide. By
arrogating to himself the power to overturn that decision,
JUSTICE BREYER does not just reject the death penalty, he
rejects the Enlightenment.
                 Cite as: 576 U. S. ____ (2015)            1

                    THOMAS, J., concurring

SUPREME COURT OF THE UNITED STATES
                         _________________

                         No. 14–7955
                         _________________


    RICHARD E. GLOSSIP, ET AL., PETITIONERS v.


             KEVIN J. GROSS, ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE TENTH CIRCUIT


                        [June 29, 2015] 


  JUSTICE THOMAS, with whom JUSTICE SCALIA joins,
concurring.
  I agree with the Court that petitioners’ Eighth Amend-
ment claim fails. That claim has no foundation in the
Eighth Amendment, which prohibits only those “method[s]
of execution” that are “deliberately designed to inflict
pain.” Baze v. Rees, 553 U. S. 35, 94 (2008) (THOMAS, J.,
concurring in judgment). Because petitioners make no
allegation that Oklahoma adopted its lethal injection
protocol “to add elements of terror, pain, or disgrace to the
death penalty,” they have no valid claim. Id., at 107.
That should have been the end of this case, but our prece-
dents have predictably transformed the federal courts
“into boards of inquiry charged with determining the ‘best
practices’ for executions,” id., at 101 (internal quotation
marks omitted), necessitating the painstaking factual
inquiry the Court undertakes today. Although I continue
to believe that the broader interpretation of the Eighth
Amendment advanced in the plurality opinion in Baze is
erroneous, I join the Court’s opinion in full because it
correctly explains why petitioners’ claim fails even under
that controlling opinion.
  I write separately to respond to JUSTICE BREYER’s dis-
sent questioning the constitutionality of the death penalty
generally. No more need be said about the constitutional
2                         GLOSSIP v. GROSS

                         THOMAS, J., concurring

arguments on which JUSTICE BREYER relies, as my col-
leagues and I have elsewhere refuted them.1 But JUSTICE
BREYER’s assertion, post, at 10, that the death penalty in
this country has fallen short of the aspiration that capital
punishment be reserved for the “worst of the worst” —a
notion itself based on an implicit proportionality principle
that has long been discredited, see Harmelin v. Michigan,

——————
   1 Generally: Baze v. Rees, 553 U. S. 35, 94–97 (2008) (THOMAS, J.,

concurring in judgment) (explaining that the Cruel and Unusual
Punishments Clause does not prohibit the death penalty, but only
torturous punishments); Graham v. Collins, 506 U. S. 461, 488 (1993)
(THOMAS, J., concurring); Gardner v. Florida, 430 U. S. 349, 371 (1977)
(Rehnquist, J., dissenting) (“The prohibition of the Eighth Amendment
relates to the character of the punishment, and not to the process by
which it is imposed”). On reliability: Kansas v. Marsh, 548 U. S. 163,
181 (2006) (noting that the death penalty remains constitutional
despite imperfections in the criminal justice system); McGautha v.
California, 402 U. S. 183, 221 (1971) (“[T]he Federal Constitution,
which marks the limits of our authority in these cases, does not guar-
antee trial procedures that are the best of all worlds, or that accord
with the most enlightened ideas of students of the infant science of
criminology, or even those that measure up to the individual predilec-
tions of members of this Court”). On arbitrariness: Ring v. Arizona,
536 U. S. 584, 610 (2002) (SCALIA, J., concurring) (explaining that what
compelled States to specify “ ‘aggravating factors’ ” designed to limit the
death penalty to the worst of the worst was this Court’s baseless
jurisprudence concerning juror discretion); McCleskey v. Kemp, 481
U. S. 279, 308–312 (1987) (noting that various procedures, including
the right to a jury trial, constitute a defendant’s protection against
arbitrariness in the application of the death penalty). On excessive
delays: Knight v. Florida, 528 U. S. 990 (1999) (THOMAS, J., concurring
in denial of certiorari) (“I am unaware of any support in the American
constitutional tradition or in this Court’s precedent for the proposition
that a defendant can avail himself of the panoply of appellate and
collateral procedures and then complain when his execution is de-
layed”); see also Johnson v. Bredesen, 558 U. S. 1067, 1070 (2009)
(THOMAS, J., concurring in denial of certiorari). And on the decline in
use of the death penalty: Atkins v. Virginia, 536 U. S. 304, 345 (2002)
(SCALIA, J., dissenting); Woodson v. North Carolina, 428 U. S. 280, 308–
310 (1976) (Rehnquist, J., dissenting).
                 Cite as: 576 U. S. ____ (2015)           3

                    THOMAS, J., concurring

501 U. S. 957, 966 (1991) (opinion of SCALIA, J.)—merits
further comment. His conclusion is based on an analysis
that itself provides a powerful case against enforcing an
imaginary constitutional rule against “arbitrariness.”
   The thrust of JUSTICE BREYER’s argument is that empir-
ical studies performed by death penalty abolitionists
reveal that the assignment of death sentences does not
necessarily correspond to the “egregiousness” of the
crimes, but instead appears to be correlated to “arbitrary”
factors, such as the locality in which the crime was com-
mitted. Relying on these studies to determine the consti-
tutionality of the death penalty fails to respect the values
implicit in the Constitution’s allocation of decisionmaking
in this context. The Donohue study, on which JUSTICE
BREYER relies most heavily, measured the “egregiousness”
(or “deathworthiness”) of murders by asking lawyers to
identify the legal grounds for aggravation in each case,
and by asking law students to evaluate written summaries
of the murders and assign “egregiousness” scores based on
a rubric designed to capture and standardize their moral
judgments. Donohue, An Empirical Evaluation of the
Connecticut Death Penalty System Since 1973, Are There
Unlawful Racial, Gender, and Geographic Disparities? 11
J. of Empirical Legal Studies 637, 644–645 (2014). This
exercise in some ways approximates the function per-
formed by jurors, but there is at least one critical differ-
ence: The law students make their moral judgments based
on written summaries—they do not sit through hours,
days, or weeks of evidence detailing the crime; they do not
have an opportunity to assess the credibility of witnesses,
to see the remorse of the defendant, to feel the impact of
the crime on the victim’s family; they do not bear the
burden of deciding the fate of another human being; and
they are not drawn from the community whose sense of
security and justice may have been torn asunder by an act
of callous disregard for human life. They are like appel-
4                         GLOSSIP v. GROSS

                         THOMAS, J., concurring

late judges and justices, reviewing only a paper record of
each side’s case for life or death.
   There is a reason the choice between life and death,
within legal limits, is left to the jurors and judges who sit
through the trial, and not to legal elites (or law students).2
That reason is memorialized not once, but twice, in our
Constitution: Article III guarantees that “[t]he Trial of all
Crimes, except in cases of Impeachment, shall be by Jury”
and that “such Trial shall be held in the State where the
said Crimes shall have been committed.” Art. III, §2, cl. 3.
And the Sixth Amendment promises that “[i]n all criminal
prosecutions, the accused shall enjoy the right to a . . .
trial, by an impartial jury of the State and district wherein
the crime shall have been committed.” Those provisions
ensure that capital defendants are given the option to be
sentenced by a jury of their peers who, collectively, are
better situated to make the moral judgment between life
and death than are the products of contemporary Ameri-
can law schools.
   It should come as no surprise, then, that the primary
explanation a regression analysis revealed for the gap
between the egregiousness scores and the actual sentences
was not the race or sex of the offender or victim, but the
locality in which the crime was committed. Donohue,
supra, at 640; see also post, at 12 (BREYER, J., dissenting).
What is more surprising is that JUSTICE BREYER considers

——————
   2 For some, a faith in the jury seems to be correlated to that institu-

tion’s likelihood of preventing imposition of the death penalty. See, e.g.,
Ring v. Arizona, 536 U. S. 584, 614 (2002) (BREYER, J., concurring in
judgment) (arguing that “the Eighth Amendment requires that a jury,
not a judge, make the decision to sentence a defendant to death”);
Wainwright v. Witt, 469 U. S. 412, 440, n. 1 (1985) (Brennan, J., dis-
senting) (“However heinous Witt’s crime, the majority’s vivid portrait of
its gruesome details has no bearing on the issue before us. It is not for
this Court to decide whether Witt deserves to die. That decision must
first be made by a jury of his peers”).
                 Cite as: 576 U. S. ____ (2015)           5

                    THOMAS, J., concurring

this factor to be evidence of arbitrariness. See ibid. The
constitutional provisions just quoted, which place such
decisions in the hands of jurors and trial courts located
where “the crime shall have been committed,” seem delib-
erately designed to introduce that factor.
   In any event, the results of these studies are inherently
unreliable because they purport to control for egregious-
ness by quantifying moral depravity in a process that is
itself arbitrary, not to mention dehumanizing. One such
study’s explanation of how the author assigned “depravity
points” to identify the “worst of the worst” murderers
proves the point well. McCord, Lightning Still Strikes, 71
Brooklyn L. Rev. 797, 833–834 (2005). Each aggravating
factor received a point value based on the “blame-
worth[iness]” of the action associated with it. Id., at 830.
Killing a prison guard, for instance, earned a defendant
three “depravity points” because it improved the case for
complete incapacitation, while killing a police officer
merited only two, because, “considered dispassionately,”
such acts do “not seem be a sine qua non of the worst
criminals.” Id., at 834–836. (Do not worry, the author
reassures us, “many killers of police officers accrue de-
pravity points in other ways that clearly put them among
the worst criminals.” Id., at 836.) Killing a child under
the age of 12 was worth two depravity points, because
such an act “seems particularly heartless,” but killing
someone over the age of 70 earned the murderer only one,
for although “elderly victims tug at our hearts,” they do so
“less” than children “because the promise of a long life is
less.” Id., at 836, 838. Killing to make a political state-
ment was worth three depravity points; killing out of
racial hatred, only two. Id., at 835, 837. It goes on, but
this small sample of the moral judgments on which this
study rested shows just how unsuitable this evidence is to
serve as a basis for a judicial decision declaring unconsti-
tutional a punishment duly enacted in more than 30
6                         GLOSSIP v. GROSS

                        THOMAS, J., concurring

States, and by the Federal Government.
   We owe victims more than this sort of pseudoscientific
assessment of their lives. It is bad enough to tell a mother
that her child’s murder is not “worthy” of society’s ulti-
mate expression of moral condemnation. But to do so
based on cardboard stereotypes or cold mathematical
calculations is beyond my comprehension. In my decades
on the Court, I have not seen a capital crime that could
not be considered sufficiently “blameworthy” to merit a
death sentence (even when genuine constitutional errors
justified a vacatur of that sentence).3
   A small sample of the applications for a stay of execu-
tion that have come before the Court this Term alone
proves my point. Mark Christeson was due to be executed
in October 2014 for his role in the murder of Susan Brouk
and her young children, Adrian and Kyle. After raping

——————
  3 For his part, JUSTICE BREYER explains that his experience on the

Court has shown him “discrepancies for which [he] can find no rational
explanations.” Post, at 16. Why, he asks, did one man receive death for
a single-victim murder, while another received life for murdering a
young mother and nearly killing her infant? Ibid. The outcomes in
those two cases may not be morally compelled, but there was certainly
a rational explanation for them: The first man, who had previously
confessed to another murder, killed a disabled man who had offered
him a place to stay for the night. State v. Badgett, 361 N. C. 234, 239–
240, 644 S. E. 2d 206, 209–210 (2007). The killer stabbed his victim’s
throat and prevented him from seeking medical attention until he bled
to death. Ibid. The second man expressed remorse for his crimes and
claimed to suffer from mental disorders. See Charbonneau, Andre
Edwards Sentenced to Life in Prison for 2001 Murder, WRAL, Mar. 26,
2004, online at http://www.wral.com/news/local/story/109648 (all Inter-
net materials as visited June 25, 2015, and available in Clerk of Court’s
case file); Charbonneau, Jury Finds Andre Edwards Guilty of First-Degree
Murder, WRAL, Mar. 23, 2004, online at http://www.wral.com/news/local/
story/109563. The other “discrepancies” similarly have “rational”
explanations, even if reasonable juries could have reached different
results.
                 Cite as: 576 U. S. ____ (2015)           7

                    THOMAS, J., concurring

Ms. Brouk at gunpoint, he and his accomplice drove the
family to a remote pond, where Christeson cut Ms. Brouk’s
throat with a bone knife. State v. Christeson, 50 S. W. 3d
251, 257–258 (Mo. 2001). Although bleeding profusely,
she stayed alive long enough to tell her children she loved
them and to watch as Christeson murdered them—her
son, by cutting his throat twice and drowning him; her
daughter, by pressing down on her throat until she suffo-
cated. Ibid. Christeson and his accomplice then threw
Ms. Brouk—alive but barely breathing—into the pond to
drown on top of her dead children. Ibid. This Court
granted him a stay of execution. Christeson v. Roper, 574
U. S. ___ (2014). Lisa Ann Coleman was not so lucky. She
was executed on September 17, 2014, for murdering her
girlfriend’s son, 9-year-old Davontae Williams, by slowly
starving him to death. Coleman v. State, 2009 WL
4696064, *1 (Tex. Crim. App., Dec. 9, 2009). When he
died, Davontae had over 250 distinct injuries—including
cigarette burns and ligature marks—on his 36-pound
frame. Id., at *2. Infections from untreated wounds con-
tributed to his other cause of death: pneumonia. Id., at
*1–*2. And Johnny Shane Kormondy, who met his end on
January 15, 2015, did so after he and his two accomplices
invaded the home of a married couple, took turns raping
the wife and forcing her to perform oral sex at gunpoint—
at one point, doing both simultaneously—and then put a
bullet in her husband’s head during the final rape. Kor-
mondy v. Secretary, Fla. Dept. of Corrections, 688 F. 3d
1244, 1247–1248 (CA11 2012).
   Some of our most “egregious” cases have been those in
which we have granted relief based on an unfounded
Eighth Amendment claim. For example, we have granted
relief in a number of egregious cases based on this Court’s
decision in Atkins v. Virginia, 536 U. S. 304 (2002), ex-
empting certain “mentally retarded” offenders from the
death penalty. Last Term, the Court granted relief to a
8                     GLOSSIP v. GROSS

                     THOMAS, J., concurring

man who kidnaped, beat, raped, and murdered a 21-year-
old pregnant newlywed, Karol Hurst, also murdering her
unborn child, and then, on the same day, murdered a
sheriff ’s deputy acting in the line of duty. Hall v. Florida,
572 U. S. ___, ___ (2014) (slip op., at 1). And in Atkins
itself, the Court granted relief to a man who carjacked
Eric Michael Nesbitt, forced him to withdraw money from
a bank, drove him to a secluded area, and then shot him
multiple times before leaving him to bleed to death. At-
kins v. Commonwealth, 257 Va. 160, 166–167, 510 S. E. 2d
445, 449–450 (1999).
   The Court has also misinterpreted the Eighth Amend-
ment to grant relief in egregious cases involving rape. In
Kennedy v. Louisiana, 554 U. S. 407 (2008), the Court
granted relief to a man who had been sentenced to death
for raping his 8-year-old stepdaughter. The rape was so
violent that it “separated her cervix from the back of her
vagina, causing her rectum to protrude into the vaginal
structure,” and tore her “entire perineum . . . from the
posterior fourchette to the anus.” Id., at 414. The evi-
dence indicated that the petitioner spent at least an hour
and half attempting to destroy the evidence of his crime
before seeking emergency assistance, even as his step-
daughter bled profusely from her injuries. Id., at 415.
And in Coker v. Georgia, 433 U. S. 584 (1977) (plurality
opinion), the Court granted relief to a petitioner who had
escaped from prison, broken into the home of a young
married couple and their newborn, forced the wife to bind
her husband, gagged her husband with her underwear,
raped her (even after being told that she was recovering
from a recent childbirth), and then kidnaped her after
threatening her husband, Coker v. State, 234 Ga. 555,
556–557, 216 S. E. 2d 782, 786–787 (1975). In each case,
the Court crafted an Eighth Amendment right to be free
from execution for the crime of rape—whether it be of an
adult, Coker, 433 U. S., at 592, or a child, Kennedy, supra,
                 Cite as: 576 U. S. ____ (2015)            9

                    THOMAS, J., concurring

at 413.
   The Court’s recent decision finding that the Eighth
Amendment prohibits the execution of those who commit-
ted their crimes as juveniles is no different. See Roper v.
Simmons, 543 U. S. 551 (2005). Although the Court had
rejected the claim less than two decades earlier, Stanford
v. Kentucky, 492 U. S. 361 (1989), it decided to revisit the
issue for a petitioner who had slain his victim because “he
wanted to murder someone” and believed he could “get
away with it” because he was a few months shy of his 18th
birthday. 543 U. S., at 556. His randomly chosen victim
was Shirley Crook, whom he and his friends kidnaped in
the middle of the night, bound with duct tape and electri-
cal wire, and threw off a bridge to drown in the river
below. Id., at 556–557. The State of Alabama’s brief in
that case warned the Court that its decision would free
from death row a number of killers who had been sen-
tenced for crimes committed as juveniles. Brief for State
of Alabama et al. as Amici Curiae in Roper v. Simmons, O.
T. 2014, No. 03–633. Mark Duke, for example, murdered
his father for refusing to loan him a truck, and his father’s
girlfriend and her two young daughters because he wanted
no witnesses to the crime. Id., at 4. He shot his father
and his father’s girlfriend pointblank in the face as they
pleaded for their lives. Id., at 5–6. He then tracked the
girls down in their hiding places and slit their throats,
leaving them alive for several minutes as they drowned in
their own blood. Id., at 6–7.
   Whatever one’s views on the permissibility or wisdom of
the death penalty, I doubt anyone would disagree that
each of these crimes was egregious enough to merit the
severest condemnation that society has to offer. The only
constitutional problem with the fact that these criminals
were spared that condemnation, while others were not, is
10                         GLOSSIP v. GROSS

                         THOMAS, J., concurring

that their amnesty came in the form of unfounded claims.
Arbitrariness has nothing to do with it.4 To the extent
that we are ill at ease with these disparate outcomes, it
seems to me that the best solution is for the Court to stop
making up Eighth Amendment claims in its ceaseless
quest to end the death penalty through undemocratic
means.




——————
  4 JUSTICE BREYER appears to acknowledge that our decision holding
mandatory death penalty schemes unconstitutional, Woodson v. North
Carolina, 428 U. S. 280 (1976) (plurality opinion), may have introduced
the problem of arbitrary application. Post, at 14. I agree that Woodson
eliminated one reliable legislative response to concerns about arbitrari-
ness. Graham v. Collins, 506 U. S. 461, 486 (1993) (THOMAS, J., concur-
ring). Because that decision was also questionable on constitutional
grounds, id., at 486–488, I would be willing to revisit it in a future case.
                 Cite as: 576 U. S. ____ (2015)           1

                    BREYER, J., dissenting

SUPREME COURT OF THE UNITED STATES
                         _________________

                         No. 14–7955
                         _________________


    RICHARD E. GLOSSIP, ET AL., PETITIONERS v.


             KEVIN J. GROSS, ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE TENTH CIRCUIT


                        [June 29, 2015]



   JUSTICE BREYER, with whom JUSTICE GINSBURG joins,
dissenting.
   For the reasons stated in JUSTICE SOTOMAYOR’s opinion,
I dissent from the Court’s holding. But rather than try to
patch up the death penalty’s legal wounds one at a time, I
would ask for full briefing on a more basic question:
whether the death penalty violates the Constitution.
   The relevant legal standard is the standard set forth in
the Eighth Amendment. The Constitution there forbids
the “inflict[ion]” of “cruel and unusual punishments.”
Amdt. 8. The Court has recognized that a “claim that
punishment is excessive is judged not by the standards
that prevailed in 1685 when Lord Jeffreys presided over
the ‘Bloody Assizes’ or when the Bill of Rights was adopted,
but rather by those that currently prevail.” Atkins v.
Virginia, 536 U. S. 304, 311 (2002). Indeed, the Constitu­
tion prohibits various gruesome punishments that were
common in Blackstone’s day. See 4 W. Blackstone, Com­
mentaries on the Laws of England 369–370 (1769) (listing
mutilation and dismembering, among other punishments).
   Nearly 40 years ago, this Court upheld the death pen­
alty under statutes that, in the Court’s view, contained
safeguards sufficient to ensure that the penalty would be
applied reliably and not arbitrarily. See Gregg v. Georgia,
428 U. S. 153, 187 (1976) (joint opinion of Stewart, Powell,
2                    GLOSSIP v. GROSS

                    BREYER, J., dissenting

and Stevens, JJ.); Proffitt v. Florida, 428 U. S. 242, 247
(1976) (joint opinion of Stewart, Powell, and Stevens, JJ.);
Jurek v. Texas, 428 U. S. 262, 268 (1976) (joint opinion of
Stewart, Powell, and Stevens, JJ.); but cf. Woodson v.
North Carolina, 428 U. S. 280, 303 (1976) (plurality opin­
ion) (striking down mandatory death penalty); Roberts v.
Louisiana, 428 U. S. 325, 331 (1976) (plurality opinion)
(similar). The circumstances and the evidence of the
death penalty’s application have changed radically since
then. Given those changes, I believe that it is now time to
reopen the question.
   In 1976, the Court thought that the constitutional in­
firmities in the death penalty could be healed; the Court in
effect delegated significant responsibility to the States to
develop procedures that would protect against those con­
stitutional problems. Almost 40 years of studies, surveys,
and experience strongly indicate, however, that this effort
has failed. Today’s administration of the death penalty
involves three fundamental constitutional defects: (1)
serious unreliability, (2) arbitrariness in application, and
(3) unconscionably long delays that undermine the death
penalty’s penological purpose. Perhaps as a result, (4)
most places within the United States have abandoned its
use.
   I shall describe each of these considerations, emphasiz­
ing changes that have occurred during the past four dec­
ades. For it is those changes, taken together with my own
20 years of experience on this Court, that lead me to be­
lieve that the death penalty, in and of itself, now likely
constitutes a legally prohibited “cruel and unusual pun­
ishmen[t].” U. S. Const., Amdt. 8.
                             I
                “Cruel”—Lack of Reliability
  This Court has specified that the finality of death cre­
ates a “qualitative difference” between the death penalty
                  Cite as: 576 U. S. ____ (2015)            3

                     BREYER, J., dissenting

and other punishments (including life in prison). Wood-
son, 428 U. S., at 305 (plurality opinion). That “qualita­
tive difference” creates “a corresponding difference in the
need for reliability in the determination that death is the
appropriate punishment in a specific case.” Ibid. There is
increasing evidence, however, that the death penalty as
now applied lacks that requisite reliability. Cf. Kansas v.
Marsh, 548 U. S. 163, 207–211 (2006) (Souter, J., dis­
senting) (DNA exonerations constitute “a new body of
fact” when considering the constitutionality of capital
punishment).
   For one thing, despite the difficulty of investigating the
circumstances surrounding an execution for a crime that
took place long ago, researchers have found convincing
evidence that, in the past three decades, innocent people
have been executed. See, e.g., Liebman, Fatal Injustice;
Carlos DeLuna’s Execution Shows That a Faster, Cheaper
Death Penalty is a Dangerous Idea, L. A. Times, June 1,
2012, p. A19 (describing results of a 4-year investigation,
later published as The Wrong Carlos: Anatomy of a
Wrongful Execution (2014), that led its authors to con­
clude that Carlos DeLuna, sentenced to death and executed
in 1989, six years after his arrest in Texas for stabbing
a single mother to death in a convenience store, was inno­
cent); Grann, Trial By Fire: Did Texas Execute An Inno­
cent Man? The New Yorker, Sept. 7, 2009, p. 42 (describ­
ing evidence that Cameron Todd Willingham was
convicted, and ultimately executed in 2004, for the appar­
ently motiveless murder of his three children as the result
of invalid scientific analysis of the scene of the house fire
that killed his children). See also, e.g., Press Release: Gov.
Ritter Grants Posthumous Pardon in Case Dating Back to
1930s, Jan. 7, 2011, p. 1 (Colorado Governor granted full
and unconditional posthumous pardon to Joe Arridy, a
man with an IQ of 46 who was executed in 1936, because,
according to the Governor, “an overwhelming body of
4                    GLOSSIP v. GROSS

                    BREYER, J., dissenting

evidence indicates the 23-year-old Arridy was innocent,
including false and coerced confessions, the likelihood that
Arridy was not in Pueblo at the time of the killing, and an
admission of guilt by someone else”); R. Warden, Wilkie
Collins’s The Dead Alive: The Novel, the Case, and Wrong­
ful Convictions 157–158 (2005) (in 1987, Nebraska Gover­
nor Bob Kerrey pardoned William Jackson Marion, who
had been executed a century earlier for the murder of
John Cameron, a man who later turned up alive; the
alleged victim, Cameron, had gone to Mexico to avoid a
shotgun wedding).
   For another, the evidence that the death penalty has
been wrongly imposed (whether or not it was carried out),
is striking. As of 2002, this Court used the word “disturb­
ing” to describe the number of instances in which individ­
uals had been sentenced to death but later exonerated. At
that time, there was evidence of approximately 60
exonerations in capital cases.       Atkins, 536 U. S., at
320, n. 25; National Registry of Exonerations, online at
http://www.law.umich.edu/special/exoneration/Pages/about.
aspx (all Internet materials as visited June 25, 2015, and
available in Clerk of Court’s case file). (I use “exonera­
tion” to refer to relief from all legal consequences of a
capital conviction through a decision by a prosecutor, a
Governor or a court, after new evidence of the defendant’s
innocence was discovered.) Since 2002, the number of
exonerations in capital cases has risen to 115. Ibid.; Na­
tional Registry of Exonerations, Exonerations in the United
States, 1989–2012, pp. 6–7 (2012) (Exonerations 2012
Report) (defining exoneration); accord, Death Penalty
Information Center (DPIC), Innocence: List of Those Freed
from Death Row, online at http://www.deathpenaltyinfo.
org/innocence-and-death-penalty (DPIC Innocence List)
(calculating, under a slightly different definition of exon­
eration, the number of exonerations since 1973 as 154).
Last year, in 2014, six death row inmates were exonerated
                 Cite as: 576 U. S. ____ (2015)            5

                     BREYER, J., dissenting

based on actual innocence. All had been imprisoned for
more than 30 years (and one for almost 40 years) at the
time of their exonerations. National Registry of Exonera­
tions, Exonerations in 2014, p. 2 (2015).
   The stories of three of the men exonerated within the
last year are illustrative. DNA evidence showed that
Henry Lee McCollum did not commit the rape and murder
for which he had been sentenced to death. Katz & Eck­
holm, DNA Evidence Clears Two Men in 1983 Murder,
N. Y. Times, Sept. 3, 2014, p. A1. Last Term, this Court
ordered that Anthony Ray Hinton, who had been convicted
of murder, receive further hearings in state court; he was
exonerated earlier this year because the forensic evidence
used against him was flawed. Hinton v. Alabama, 571
U. S. ___ (2014) (per curiam); Blinder, Alabama Man on
Death Row for Three Decades Is Freed as State’s Case
Erodes, N. Y. Times, Apr. 4, 2014, p. A11. And when
Glenn Ford, also convicted of murder, was exonerated, the
prosecutor admitted that even “[a]t the time this case was
tried there was evidence that would have cleared Glenn
Ford.” Stroud, Lead Prosecutor Apologizes for Role in
Sending Man to Death Row, Shreveport Times, Mar. 27,
2015. All three of these men spent 30 years on death row
before being exonerated. I return to these examples infra.
   Furthermore, exonerations occur far more frequently
where capital convictions, rather than ordinary criminal
convictions, are at issue. Researchers have calculated that
courts (or State Governors) are 130 times more likely to
exonerate a defendant where a death sentence is at issue.
They are nine times more likely to exonerate where a
capital murder, rather than a noncapital murder, is at
issue. Exonerations 2012 Report 15–16, and nn. 24–26.
   Why is that so? To some degree, it must be because the
law that governs capital cases is more complex. To some
degree, it must reflect the fact that courts scrutinize capi­
tal cases more closely. But, to some degree, it likely also
6                    GLOSSIP v. GROSS

                    BREYER, J., dissenting

reflects a greater likelihood of an initial wrongful convic­
tion. How could that be so? In the view of researchers
who have conducted these studies, it could be so because
the crimes at issue in capital cases are typically horren­
dous murders, and thus accompanied by intense community
pressure on police, prosecutors, and jurors to secure a
conviction. This pressure creates a greater likelihood of
convicting the wrong person. See Gross, Jacoby, Mathe-
son, Montgomery, & Patil, Exonerations in the United
States 1989 Through 2003, 95 J. Crim. L. & C. 523, 531–
533 (2005); Gross & O’Brien, Frequency and Predictors of
False Conviction: Why We Know So Little, and New Data
on Capital Cases, 5 J. Empirical L. Studies 927, 956–957
(2008) (noting that, in comparing those who were exoner­
ated from death row to other capital defendants who were
not so exonerated, the initial police investigations tended
to be shorter for those exonerated); see also B. Garrett,
Convicting the Innocent: Where Criminal Prosecutions Go
Wrong (2011) (discussing other common causes of wrong­
ful convictions generally including false confessions, mis­
taken eyewitness testimony, untruthful jailhouse inform­
ants, and ineffective defense counsel).
   In the case of Cameron Todd Willingham, for example,
who (as noted earlier) was executed despite likely inno­
cence, the State Bar of Texas recently filed formal miscon­
duct charges against the lead prosecutor for his actions—
actions that may have contributed to Willingham’s convic­
tion. Possley, Prosecutor Accused of Misconduct in Death
Penalty Case, Washington Post, Mar. 19, 2015, p. A3. And
in Glenn Ford’s case, the prosecutor admitted that he was
partly responsible for Ford’s wrongful conviction, issuing a
public apology to Ford and explaining that, at the time of
Ford’s conviction, he was “not as interested in justice as
[he] was in winning.” Stroud, supra.
   Other factors may also play a role. One is the practice
of death-qualification; no one can serve on a capital jury
                 Cite as: 576 U. S. ____ (2015)            7

                     BREYER, J., dissenting

who is not willing to impose the death penalty. See
Rozelle, The Principled Executioner: Capital Juries’ Bias
and the Benefits of True Bifurcation, 38 Ariz. S. L. J. 769,
772–793, 807 (2006) (summarizing research and conclud­
ing that “[f]or over fifty years, empirical investigation has
demonstrated that death qualification skews juries toward
guilt and death”); Note, Mandatory Voir Dire Questions in
Capital Cases: A Potential Solution to the Biases of Death
Qualification, 10 Roger Williams Univ. L. Rev. 211, 214–
223 (2004) (similar).
   Another is the more general problem of flawed forensic
testimony. See Garrett, supra, at 7. The Federal Bureau
of Investigation (FBI), for example, recently found that
flawed microscopic hair analysis was used in 33 of 35
capital cases under review; 9 of the 33 had already been
executed. FBI, National Press Releases, FBI Testimony
on Microscopic Hair Analysis Contained Errors in at Least
90 Percent of Cases in Ongoing Review, Apr. 20, 2015.
See also Hsu, FBI Admits Errors at Trials: False Matches
on Crime-Scene Hair, Washington Post, Apr. 19, 2015,
p. A1 (in the District of Columbia, which does not have the
death penalty, five of seven defendants in cases with
flawed hair analysis testimony were eventually exonerated).
   In light of these and other factors, researchers estimate
that about 4% of those sentenced to death are actually
innocent. See Gross, O’Brien, Hu, & Kennedy, Rate of
False Conviction of Criminal Defendants Who Are Sen­
tenced to Death, 111 Proceeding of the National Academy
of Sciences 7230 (2014) (full-scale study of all death sen­
tences from 1973 through 2004 estimating that 4.1% of
those sentenced to death are actually innocent); Risinger,
Innocents Convicted: An Empirically Justified Factual
Wrongful Conviction Rate, 97 J. Crim. L. & C. 761 (2007)
(examination of DNA exonerations in death penalty cases
for murder-rapes between 1982 and 1989 suggesting an
analogous rate of between 3.3% and 5%).
8                    GLOSSIP v. GROSS

                    BREYER, J., dissenting

  Finally, if we expand our definition of “exoneration”
(which we limited to errors suggesting the defendant was
actually innocent) and thereby also categorize as “errone­
ous” instances in which courts failed to follow legally
required procedures, the numbers soar. Between 1973
and 1995, courts identified prejudicial errors in 68% of the
capital cases before them. Gelman, Liebman, West, &
Kiss, A Broken System: The Persistent Patterns of Rever­
sals of Death Sentences in the United States, 1 J. Empiri­
cal L. Studies 209, 217 (2004). State courts on direct and
postconviction review overturned 47% of the sentences
they reviewed. Id., at 232. Federal courts, reviewing
capital cases in habeas corpus proceedings, found error in
40% of those cases. Ibid.
  This research and these figures are likely controversial.
Full briefing would allow us to scrutinize them with more
care. But, at a minimum, they suggest a serious problem
of reliability. They suggest that there are too many in­
stances in which courts sentence defendants to death
without complying with the necessary procedures; and
they suggest that, in a significant number of cases, the
death sentence is imposed on a person who did not commit
the crime. See Earley, A Pink Cadillac, An IQ of 63, and A
Fourteen-Year-Old from South Carolina: Why I Can No
Longer Support the Death Penalty, 49 U. Rich. L. Rev.
811, 813 (2015) (“I have come to the conclusion that the
death penalty is based on a false utopian premise. That
false premise is that we have had, do have, will have 100%
accuracy in death penalty convictions and executions”);
Earley, I Oversaw 36 Executions. Even Death Penalty
Supporters Can Push for Change, Guardian, May 12, 2014
(Earley presided over 36 executions as Virginia Attorney
General from 1998–2001); but see ante, at 2–3 (SCALIA, J.,
concurring) (apparently finding no special constitutional
problem arising from the fact that the execution of an
innocent person is irreversible). Unlike 40 years ago, we
                 Cite as: 576 U. S. ____ (2015)            9

                     BREYER, J., dissenting

now have plausible evidence of unreliability that (perhaps
due to DNA evidence) is stronger than the evidence we
had before. In sum, there is significantly more research-
based evidence today indicating that courts sentence to
death individuals who may well be actually innocent or
whose convictions (in the law’s view) do not warrant the
death penalty’s application.
                             II
                   “Cruel”—Arbitrariness
   The arbitrary imposition of punishment is the antithesis
of the rule of law. For that reason, Justice Potter Stewart
(who supplied critical votes for the holdings in Furman v.
Georgia, 408 U. S. 238 (1972) (per curiam), and Gregg)
found the death penalty unconstitutional as administered
in 1972:
    “These death sentences are cruel and unusual in the
    same way that being struck by lightning is cruel and
    unusual. For, of all the people convicted of [death­
    eligible crimes], many just as reprehensible as these,
    the[se] petitioners are among a capriciously selected
    random handful upon which the sentence of death has
    in fact been imposed.” Furman, 408 U. S., at 309–310
    (concurring opinion).
See also id., at 310 (“[T]he Eighth and Fourteenth
Amendments cannot tolerate the infliction of a sentence of
death under legal systems that permit this unique penalty
to be so wantonly and so freakishly imposed”); id., at 313
(White, J., concurring) (“[T]he death penalty is exacted
with great infrequency even for the most atrocious crimes
and . . . there is no meaningful basis for distinguishing the
few cases in which it is imposed from the many cases in
which it is not”).
  When the death penalty was reinstated in 1976, this
Court acknowledged that the death penalty is (and would
10                   GLOSSIP v. GROSS

                     BREYER, J., dissenting

be) unconstitutional if “inflicted in an arbitrary and capri­
cious manner.” Gregg, 428 U. S., at 188 (joint opinion of
Stewart, Powell, and Stevens, JJ.); see also id., at 189
(“[W]here discretion is afforded a sentencing body on a
matter so grave as the determination of whether a human
life should be taken or spared, that discretion must be
suitably directed and limited so as to minimize the risk of
wholly arbitrary and capricious action”); Godfrey v. Geor­
gia, 446 U. S. 420, 428 (1980) (plurality opinion) (similar).
   The Court has consequently sought to make the applica­
tion of the death penalty less arbitrary by restricting its
use to those whom Justice Souter called “ ‘the worst of the
worst.’ ” Kansas v. Marsh, 548 U. S., at 206 (dissenting
opinion); see also Roper v. Simmons, 543 U. S. 551, 568
(2005) (“Capital punishment must be limited to those
offenders who commit a narrow category of the most seri­
ous crimes and whose extreme culpability makes them the
most deserving of execution” (internal quotation marks
omitted)); Kennedy v. Louisiana, 554 U. S. 407, 420 (2008)
(citing Roper, supra, at 568).
   Despite the Gregg Court’s hope for fair administration of
the death penalty, 40 years of further experience make it
increasingly clear that the death penalty is imposed arbi­
trarily, i.e., without the “reasonable consistency” legally
necessary to reconcile its use with the Constitution’s
commands. Eddings v. Oklahoma, 455 U. S. 104, 112
(1982).
   Thorough studies of death penalty sentences support
this conclusion. A recent study, for example, examined all
death penalty sentences imposed between 1973 and 2007
in Connecticut, a State that abolished the death penalty in
2012. Donohue, An Empirical Evaluation of the Connecti­
cut Death Penalty System Since 1973: Are There Unlawful
Racial, Gender, and Geographic Disparities? 11 J. Empiri­
cal Legal Studies 637 (2014). The study reviewed treat­
ment of all homicide defendants. It found 205 instances in
                 Cite as: 576 U. S. ____ (2015)          11

                    BREYER, J., dissenting

which Connecticut law made the defendant eligible for a
death sentence. Id., at 641–643. Courts imposed a death
sentence in 12 of these 205 cases, of which 9 were sus­
tained on appeal. Id., at 641. The study then measured
the “egregiousness” of the murderer’s conduct in those 9
cases, developing a system of metrics designed to do so.
Id., at 643–645. It then compared the egregiousness of the
conduct of the 9 defendants sentenced to death with the
egregiousness of the conduct of defendants in the remain­
ing 196 cases (those in which the defendant, though found
guilty of a death-eligible offense, was ultimately not sen­
tenced to death). Application of the studies’ metrics made
clear that only 1 of those 9 defendants was indeed the
“worst of the worst” (or was, at least, within the 15%
considered most “egregious”). The remaining eight were
not. Their behavior was no worse than the behavior of at
least 33 and as many as 170 other defendants (out of a
total pool of 205) who had not been sentenced to death.
Id., at 678–679.
  Such studies indicate that the factors that most clearly
ought to affect application of the death penalty—namely,
comparative egregiousness of the crime—often do not.
Other studies show that circumstances that ought not to
affect application of the death penalty, such as race, gen­
der, or geography, often do.
  Numerous studies, for example, have concluded that
individuals accused of murdering white victims, as op­
posed to black or other minority victims, are more likely to
receive the death penalty. See GAO, Report to the Senate
and House Committees on the Judiciary: Death Penalty
Sentencing 5 (GAO/GGD–90–57, 1990) (82% of the 28
studies conducted between 1972 and 1990 found that race
of victim influences capital murder charge or death sen­
tence, a “finding . . . remarkably consistent across data
sets, states, data collection methods, and analytic tech­
niques”); Shatz & Dalton, Challenging the Death Penalty
12                   GLOSSIP v. GROSS

                    BREYER, J., dissenting

with Statistics: Furman, McCleskey, and a Single County
Case Study, 34 Cardozo L. Rev. 1227, 1245–1251 (2013)
(same conclusion drawn from 20 plus studies conducted
between 1990 and 2013).
   Fewer, but still many, studies have found that the gen­
der of the defendant or the gender of the victim makes a
not-otherwise-warranted difference. Id., at 1251–1253
(citing many studies).
   Geography also plays an important role in determining
who is sentenced to death. See id., at 1253–1256. And
that is not simply because some States permit the death
penalty while others do not. Rather within a death pen­
alty State, the imposition of the death penalty heavily de-
pends on the county in which a defendant is tried. Smith,
The Geography of the Death Penalty and its Ramifica­
tions, 92 B. U. L. Rev. 227, 231–232 (2012) (hereinafter
Smith); see also Donohue, supra, at 673 (“[T]he single
most important influence from 1973–2007 explaining
whether a death-eligible defendant [in Connecticut] would
be sentenced to death was whether the crime occurred in
Waterbury [County]”). Between 2004 and 2009, for exam­
ple, just 29 counties (fewer than 1% of counties in the
country) accounted for approximately half of all death
sentences imposed nationwide. Smith 233. And in 2012,
just 59 counties (fewer than 2% of counties in the country)
accounted for all death sentences imposed nationwide.
DPIC, The 2% Death Penalty: How A Minority of Counties
Produce Most Death Cases At Enormous Costs to All 9
(Oct. 2013).
   What accounts for this county-by-county disparity?
Some studies indicate that the disparity reflects the deci­
sionmaking authority, the legal discretion, and ultimately
the power of the local prosecutor. See, e.g., Goelzhauser,
Prosecutorial Discretion Under Resource Constraints:
Budget Allocations and Local Death-Charging Decisions,
96 Judicature 161, 162–163 (2013); Barnes, Sloss, &
                 Cite as: 576 U. S. ____ (2015)          13

                    BREYER, J., dissenting

Thaman, Place Matters (Most): An Empirical Study of
Prosecutorial Decision-Making in Death-Eligible Cases, 51
Ariz. L. Rev. 305 (2009) (analyzing Missouri); Donohue,
An Empirical Evaluation of the Connecticut Death Pen-
alty System, at 681 (Connecticut); Marceau, Kamin, &
Foglia, Death Eligibility in Colorado: Many Are Called,
Few Are Chosen, 84 U. Colo. L. Rev. 1069 (2013) (Colo-
rado); Shatz & Dalton, supra, at 1260–1261 (Alameda
County).
   Others suggest that the availability of resources for
defense counsel (or the lack thereof) helps explain geo­
graphical differences. See, e.g., Smith 258–265 (counties
with higher death-sentencing rates tend to have weaker
public defense programs); Liebman & Clarke, Minority
Practice, Majority’s Burden: The Death Penalty Today, 9
Ohio S. J. Crim. L. 255, 274 (2011) (hereinafter Liebman
& Clarke) (similar); see generally Bright, Counsel for the
Poor: The Death Sentence Not for the Worst Crime but for
the Worst Lawyer, 103 Yale L. J. 1835 (1994).
   Still others indicate that the racial composition of and
distribution within a county plays an important role. See,
e.g., Levinson, Smith, & Young, Devaluing Death: An
Empirical Study of Implicit Racial Bias on Jury-Eligible
Citizens in Six Death Penalty States, 89 N. Y. U. L. Rev.
513, 533–536 (2014) (summarizing research on this point);
see also Shatz & Dalton, supra, at 1275 (describing re­
search finding that death-sentencing rates were lowest in
counties with the highest nonwhite population); cf. Cohen
& Smith, The Racial Geography of the Federal Death
Penalty, 85 Wash. L. Rev. 425 (2010) (arguing that the
federal death penalty is sought disproportionately where
the federal district, from which the jury will be drawn, has
a dramatic racial difference from the county in which the
federal crime occurred).
   Finally, some studies suggest that political pressures,
including pressures on judges who must stand for election,
14                   GLOSSIP v. GROSS

                     BREYER, J., dissenting

can make a difference. See Woodward v. Alabama, 571
U. S. ___, ___ (2013) (SOTOMAYOR, J., dissenting from
denial of certiorari) (slip op., at 7) (noting that empirical
evidence suggests that, when Alabama judges reverse jury
recommendations, these “judges, who are elected in parti­
san proceedings, appear to have succumbed to electoral
pressures”); Harris v. Alabama, 513 U. S. 504, 519 (1995)
(Stevens, J., dissenting) (similar); Gelman, 1 J. Empirical
L. Studies, at 247 (elected state judges are less likely to
reverse flawed verdicts in capital cases in small towns
than in larger communities).
   Thus, whether one looks at research indicating that
irrelevant or improper factors—such as race, gender, local
geography, and resources—do significantly determine who
receives the death penalty, or whether one looks at re­
search indicating that proper factors—such as “egregious­
ness”—do not determine who receives the death penalty,
the legal conclusion must be the same: The research
strongly suggests that the death penalty is imposed
arbitrarily.
   JUSTICE THOMAS catalogues the tragic details of various
capital cases, ante, at 6–10 (concurring opinion), but this
misses my point. Every murder is tragic, but unless we
return to the mandatory death penalty struck down in
Woodson, 428 U. S., at 304–305, the constitutionality of
capital punishment rests on its limited application to the
worst of the worst, supra, at 9–10. And this extensive
body of evidence suggests that it is not so limited.
   Four decades ago, the Court believed it possible to in­
terpret the Eighth Amendment in ways that would signifi­
cantly limit the arbitrary application of the death sen­
tence. See Gregg, 428 U. S., at 195 (joint opinion of
Stewart, Powell, and Stevens, JJ.) (“[T]he concerns ex­
pressed in Furman that the penalty of death not be im­
posed in an arbitrary or capricious manner can be met”).
But that no longer seems likely.
                 Cite as: 576 U. S. ____ (2015)           15

                     BREYER, J., dissenting

   The Constitution does not prohibit the use of prosecuto­
rial discretion. Id., at 199, and n. 50 (joint opinion of
Stewart, Powell, and Stevens, JJ.); McCleskey v. Kemp,
481 U. S. 279, 307–308, and n. 28, 311–312 (1987). It has
not proved possible to increase capital defense funding
significantly. Smith, The Supreme Court and the Politics
of Death, 94 Va. L. Rev. 283, 355 (2008) (“Capital defend­
ers are notoriously underfunded, particularly in states . . .
that lead the nation in executions”); American Bar Assn.
(ABA) Guidelines for the Appointment and Performance of
Defense Counsel in Death Penalty Cases, Guideline 9.1,
Commentary (rev. ed. Feb. 2003), in 31 Hofstra L. Rev.
913, 985 (2003) (“[C]ompensation of attorneys for death
penalty representation remains notoriously inadequate”).
And courts cannot easily inquire into judicial motivation.
See, e.g., Harris, supra.
   Moreover, racial and gender biases may, unfortunately,
reflect deeply rooted community biases (conscious or un­
conscious), which, despite their legal irrelevance, may
affect a jury’s evaluation of mitigating evidence, see
Callins v. Collins, 510 U. S. 1141, 1153 (1994) (Blackmun,
J., dissenting from denial of certiorari) (“Perhaps it should
not be surprising that the biases and prejudices that infect
society generally would influence the determination of
who is sentenced to death”). Nevertheless, it remains the
jury’s task to make the individualized assessment of
whether the defendant’s mitigation evidence entitles him
to mercy. See, e.g., Penry v. Lynaugh, 492 U. S. 302, 319
(1989); Lockett v. Ohio, 438 U. S. 586, 604–605 (1978)
(opinion of Burger, C. J.); Woodson, 428 U. S., at 304–305
(plurality opinion).
   Finally, since this Court held that comparative propor­
tionality review is not constitutionally required, Pulley v.
Harris, 465 U. S. 37 (1984), it seems unlikely that appeals
can prevent the arbitrariness I have described. See
Kaufman-Osborn, Capital Punishment, Proportionality
16                   GLOSSIP v. GROSS

                    BREYER, J., dissenting

Review, and Claims of Fairness (with Lessons from Wash­
ington State), 79 Wash. L. Rev. 775, 791–792 (2004) (after
Pulley, many States repealed their statutes requiring
comparative proportionality review, and most state high
courts “reduced proportionality review to a perfunctory
exercise” (internal quotation marks omitted)).
   The studies bear out my own view, reached after consid­
ering thousands of death penalty cases and last-minute
petitions over the course of more than 20 years. I see
discrepancies for which I can find no rational explana­
tions. Cf. Godfrey, 446 U. S., at 433 (plurality opinion)
(“There is no principled way to distinguish this case, in
which the death penalty was imposed, from the many
cases in which it was not”). Why does one defendant who
committed a single-victim murder receive the death pen­
alty (due to aggravators of a prior felony conviction and an
after-the-fact robbery), while another defendant does not,
despite having kidnapped, raped, and murdered a young
mother while leaving her infant baby to die at the scene of
the crime. Compare State v. Badgett, 361 N. C. 234, 644
S. E. 2d 206 (2007), and Pet. for Cert. in Badgett v. North
Carolina, O. T. 2006, No. 07–6156, with Charbonneau,
Andre Edwards Sentenced to Life in Prison for 2001 Mur­
der, WRAL, Mar. 26, 2004, online at http://www.wral.
com/news/local/story/109648. Why does one defendant who
committed a single-victim murder receive the death pen­
alty (due to aggravators of a prior felony conviction and
acting recklessly with a gun), while another defendant
does not, despite having committed a “triple murder” by
killing a young man and his pregnant wife? Compare
Commonwealth v. Boxley, 596 Pa. 620, 948 A. 2d 742
(2008), and Pet. for Cert., O. T. 2008, No. 08–6172, with
Shea, Judge Gives Consecutive Life Sentences for Triple
Murder, Philadelphia Inquirer, June 29, 2004, p. B5. For
that matter, why does one defendant who participated in a
single-victim murder-for-hire scheme (plus an after-the­
                  Cite as: 576 U. S. ____ (2015)            17

                     BREYER, J., dissenting

fact robbery) receive the death penalty, while another
defendant does not, despite having stabbed his wife 60
times and killed his 6-year-old daughter and 3-year-old
son while they slept? See Donohue, Capital Punishment
in Connecticut, 1973–2007: A Comprehensive Evaluation
from 4686 Murders to One Execution, pp. 128–134 (2013),
online at http://works.bepress.com/john_donohue/87. In
each instance, the sentences compared were imposed in
the same State at about the same time.
  The question raised by these examples (and the many
more I could give but do not), as well as by the research to
which I have referred, is the same question Justice Stew­
art, Justice Powell, and others raised over the course of
several decades: The imposition and implementation of the
death penalty seems capricious, random, indeed, arbi­
trary. From a defendant’s perspective, to receive that
sentence, and certainly to find it implemented, is the
equivalent of being struck by lightning. How then can we
reconcile the death penalty with the demands of a Consti­
tution that first and foremost insists upon a rule of law?
                             III
                  “Cruel”—Excessive Delays
   The problems of reliability and unfairness almost inevi­
tably lead to a third independent constitutional problem:
excessively long periods of time that individuals typically
spend on death row, alive but under sentence of death.
That is to say, delay is in part a problem that the Consti­
tution’s own demands create. Given the special need for
reliability and fairness in death penalty cases, the Eighth
Amendment does, and must, apply to the death penalty
“with special force.” Roper, 543 U. S., at 568. Those who
face “that most severe sanction must have a fair oppor­
tunity to show that the Constitution prohibits their execu­
tion.” Hall v. Florida, 572 U. S. ___, ___ (2014) (slip op., at
22). At the same time, the Constitution insists that “every
18                   GLOSSIP v. GROSS

                     BREYER, J., dissenting

safeguard” be “observed” when “a defendant’s life is at
stake.” Gregg, 428 U. S., at 187 (joint opinion of Stewart,
Powell, and Stevens, JJ.); Furman, 408 U. S., at 306
(Stewart, J., concurring) (death “differs from all other
forms of criminal punishment, not in degree but in kind”);
Woodson, supra, at 305 (plurality opinion) (“Death, in its
finality, differs more from life imprisonment than a 100­
year prison term differs from one of only a year or two”).
   These procedural necessities take time to implement.
And, unless we abandon the procedural requirements that
assure fairness and reliability, we are forced to confront
the problem of increasingly lengthy delays in capital cases.
Ultimately, though these legal causes may help to explain,
they do not mitigate the harms caused by delay itself.
                             A
   Consider first the statistics. In 2014, 35 individuals
were executed. Those executions occurred, on average,
nearly 18 years after a court initially pronounced its
sentence of death. DPIC, Execution List 2014, online
at http: / / www.deathpenaltyinfo.org / execution - list-2014
(showing an average delay of 17 years, 7 months). In some
death penalty States, the average delay is longer. In
an oral argument last year, for example, the State admit­
ted that the last 10 prisoners executed in Florida had
spent an average of nearly 25 years on death row before
execution. Tr. of Oral Arg. in Hall v. Florida, O. T. 2013,
No. 12–10882, p. 46.
   The length of the average delay has increased dramati­
cally over the years. In 1960, the average delay between
sentencing and execution was two years. See Aarons, Can
Inordinate Delay Between a Death Sentence and Execu­
tion Constitute Cruel and Unusual Punishment? 29 Seton
Hall L. Rev. 147, 181 (1998). Ten years ago (in 2004) the
average delay was about 11 years. See Dept. of Justice,
Bureau of Justice Statistics (BJS), T. Snell, Capital Pun­
                 Cite as: 576 U. S. ____ (2015)          19

                    BREYER, J., dissenting

ishment, 2013—Statistical Tables 14 (Table 10) (rev. Dec.
2014) (hereinafter BJS 2013 Stats). By last year the
average had risen to about 18 years. DPIC, Execution List
2014, supra. Nearly half of the 3,000 inmates now on
death row have been there for more than 15 years. And,
at present execution rates, it would take more than 75
years to carry out those 3,000 death sentences; thus, the
average person on death row would spend an additional
37.5 years there before being executed. BJS 2013 Stats, at
14, 18 (Tables 11 and 15).
  I cannot find any reasons to believe the trend will soon
be reversed.
                             B
  These lengthy delays create two special constitutional
difficulties. See Johnson v. Bredesen, 558 U. S. 1067, 1069
(2009) (Stevens, J., statement respecting denial of certio­
rari). First, a lengthy delay in and of itself is especially
cruel because it “subjects death row inmates to decades of
especially severe, dehumanizing conditions of confine­
ment.” Ibid.; Gomez v. Fierro, 519 U. S. 918 (1996) (Ste­
vens, J., dissenting) (excessive delays from sentencing to
execution can themselves “constitute cruel and unusual
punishment prohibited by the Eighth Amendment”); see
also Lackey v. Texas, 514 U. S. 1045 (1995) (memorandum
of Stevens, J., respecting denial of certiorari); Knight v.
Florida, 528 U. S. 990, 993 (1999) (BREYER, J., dissenting
from denial of certiorari). Second, lengthy delay under­
mines the death penalty’s penological rationale. Johnson,
supra, at 1069; Thompson v. McNeil, 556 U. S. 1114,
1115 (2009) (statement of Stevens, J., respecting denial of
certiorari).
                            1
  Turning to the first constitutional difficulty, nearly all
death penalty States keep death row inmates in isolation
20                   GLOSSIP v. GROSS

                    BREYER, J., dissenting

for 22 or more hours per day. American Civil Liberties
Union (ACLU), A Death Before Dying: Solitary Confine­
ment on Death Row 5 (July 2013) (ACLU Report). This
occurs even though the ABA has suggested that death row
inmates be housed in conditions similar to the general
population, and the United Nations Special Rapporteur on
Torture has called for a global ban on solitary confinement
longer than 15 days. See id., at 2, 4; ABA Standards for
Criminal Justice: Treatment of Prisoners 6 (3d ed. 2011).
And it is well documented that such prolonged solitary
confinement produces numerous deleterious harms. See,
e.g., Haney, Mental Health Issues in Long-Term Solitary
and “Supermax” Confinement, 49 Crime & Delinquency
124, 130 (2003) (cataloguing studies finding that solitary
confinement can cause prisoners to experience “anxiety,
panic, rage, loss of control, paranoia, hallucinations, and
self-mutilations,” among many other symptoms); Grassian,
Psychiatric Effects of Solitary Confinement, 22 Wash
U. J. L. & Policy 325, 331 (2006) (“[E]ven a few days of
solitary confinement will predictably shift the [brain’s]
electroencephalogram (EEG) pattern toward an abnormal
pattern characteristic of stupor and delirium”); accord, In
re Medley, 134 U. S. 160, 167–168 (1890); see also Davis v.
Ayala, ante, at 1–4 (KENNEDY, J., concurring).
   The dehumanizing effect of solitary confinement is
aggravated by uncertainty as to whether a death sentence
will in fact be carried out. In 1890, this Court recognized
that, “when a prisoner sentenced by a court to death is
confined in the penitentiary awaiting the execution of the
sentence, one of the most horrible feelings to which he can
be subjected during that time is the uncertainty during
the whole of it.” Medley, supra, at 172. The Court was
there describing a delay of a mere four weeks. In the past
century and a quarter, little has changed in this respect—
except for duration. Today we must describe delays meas­
ured, not in weeks, but in decades. Supra, at 18–19.
                 Cite as: 576 U. S. ____ (2015)         21

                    BREYER, J., dissenting

   Moreover, we must consider death warrants that have
been issued and revoked, not once, but repeatedly. See,
e.g., Pet. for Cert. in Suárez Medina v. Texas, O. T. 2001,
No. 02–5752, pp. 35–36 (filed Aug. 13, 2002) (“On fourteen
separate occasions since Mr. Suárez Medina’s death sen­
tence was imposed, he has been informed of the time, date,
and manner of his death. At least eleven times, he
has been asked to describe the disposal of his bodily
remains”); Lithwick, Cruel but not Unusual, Slate,
Apr. 1, 2011, online at http://www.slate.com/articles/
news_and_politics/jurisprudence/2011/04/cruel_but_not_
unusual.html (John Thompson had seven death warrants
signed before he was exonerated); see also, e.g., WFMZ-TV
69 News, Michael John Parrish’s Execution Warrant
Signed by Governor Corbett (Aug. 18, 2014), online at
http: / / www.wfmz.com /news/Regional-Poconos-Coal / Local/
michael-john-parrishs-execution-warrant-signed-by-governor-
corbett/27595356 (former Pennsylvania Governor signed
36 death warrants in his first 3.5 years in office even
though Pennsylvania has not carried out an execution
since 1999).
   Several inmates have come within hours or days of
execution before later being exonerated. Willie Manning
was four hours from his scheduled execution before the
Mississippi Supreme Court stayed the execution. See
Robertson, With Hours to Go, Execution is Postponed,
N. Y. Times, Apr. 8, 2015, p. A17. Two years later, Man­
ning was exonerated after the evidence against him, in­
cluding flawed testimony from an FBI hair examiner, was
severely undermined. Nave, Why Does the State Still
Want to Kill Willie Jerome Manning? Jackson Free Press,
Apr. 29, 2015. Nor is Manning an outlier case. See, e.g.,
Martin, Randall Adams, 61, Dies; Freed With Help of
Film, N. Y. Times, June 26, 2011, p. 24 (Randall Adams:
stayed by this Court three days before execution; later
exonerated); N. Davies, White Lies 231, 292, 298, 399
22                    GLOSSIP v. GROSS

                     BREYER, J., dissenting

(1991) (Clarence Lee Brandley: execution stayed twice,
once 6 days and once 10 days before; later exonerated); M.
Edds, An Expendable Man 93 (2003) (Earl Washington,
Jr.: stayed 9 days before execution; later exonerated).
   Furthermore, given the negative effects of confinement
and uncertainty, it is not surprising that many inmates
volunteer to be executed, abandoning further appeals.
See, e.g., ACLU Report 8; Rountree, Volunteers for Execu­
tion: Directions for Further Research into Grief, Culpabil­
ity, and Legal Structures, 82 UMKC L. Rev. 295 (2014)
(11% of those executed have dropped appeals and volun­
teered); ACLU Report 3 (account of “ ‘guys who dropped
their appeals because of the intolerable conditions’ ”).
Indeed, one death row inmate, who was later exonerated,
still said he would have preferred to die rather than to
spend years on death row pursuing his exoneration.
Strafer, Volunteering for Execution: Competency, Volun­
tariness and the Propriety of Third Party Intervention, 74
J. Crim. L. & C. 860, 869 (1983). Nor is it surprising that
many inmates consider, or commit, suicide. Id., at 872, n.
44 (35% of those confined on death row in Florida at­
tempted suicide).
   Others have written at great length about the constitu­
tional problems that delays create, and, rather than re­
peat their facts, arguments, and conclusions, I simply
refer to some of their writings. See, e.g., Johnson, 558
U. S., at 1069 (statement of Stevens, J.) (delay “subjects
death row inmates to decades of especially severe, dehu­
manizing conditions of confinement”); Furman, 408 U. S.,
at 288 (Brennan, J., concurring) (“long wait between the
imposition of sentence and the actual infliction of death” is
“inevitable” and often “exacts a frightful toll”); Solesbee v.
Balkcom, 339 U. S. 9, 14 (1950) (Frankfurter, J., dissent­
ing) (“In the history of murder, the onset of insanity while
awaiting execution of a death sentence is not a rare phe­
nomenon”); People v. Anderson, 6 Cal. 3d 628, 649, 493 P.
                  Cite as: 576 U. S. ____ (2015)           23

                     BREYER, J., dissenting

2d 880, 894 (1972) (collecting sources) (“[C]ruelty of capital
punishment lies not only in the execution itself and the
pain incident thereto, but also in the dehumanizing effects
of the lengthy imprisonment prior to execution during
which the judicial and administrative procedures essential
to due process of law are carried out” (footnote omitted));
District Attorney for Suffolk Dist. v. Watson, 381 Mass.
648, 673, 411 N. E. 2d 1274, 1287 (1980) (Braucher, J.,
concurring) (death penalty unconstitutional under State
Constitution in part because “[it] will be carried out only
after agonizing months and years of uncertainty”); see also
Riley v. Attorney General of Jamaica, [1983] 1 A. C. 719,
734–735 (P. C. 1982) (Lord Scarman, joined by Lord
Brightman, dissenting) (“execution after inordinate delay”
would infringe prohibition against “cruel and unusual
punishments” in §10 of the “Bill of Rights of 1689,” the
precursor to our Eighth Amendment); Pratt v. Attorney
Gen. of Jamaica, [1994] 2 A. C. 1, 4 (P. C. 1993); id., at 32–
33 (collecting cases finding inordinate delays unconstitu­
tional or the equivalent); State v. Makwanyane 1995 (3)
SA391 (CC) (S. Afr.); Catholic Commission for Justice &
Peace in Zimbabwe v. Attorney-General, [1993] 1 Zim.
L. R. 242, 282 (inordinate delays unconstitutional); Soer­
ing v. United Kingdom, 11 Eur. Ct. H. R. (ser. A), p. 439
(1989) (extradition of murder suspect to United States
would violate the European Convention on Human Rights
in light of risk of delay before execution); United States v.
Burns, [2001] 1 S. C. R. 283, 353, ¶123 (similar).
                              2
  The second constitutional difficulty resulting from
lengthy delays is that those delays undermine the death
penalty’s penological rationale, perhaps irreparably so.
The rationale for capital punishment, as for any punish­
ment, classically rests upon society’s need to secure deter­
rence, incapacitation, retribution, or rehabilitation. Capi­
24                   GLOSSIP v. GROSS

                    BREYER, J., dissenting

tal punishment by definition does not rehabilitate. It
does, of course, incapacitate the offender. But the major
alternative to capital punishment—namely, life in prison
without possibility of parole—also incapacitates. See Ring
v. Arizona, 536 U. S. 584, 615 (2002) (BREYER, J., concur­
ring in judgment).
   Thus, as the Court has recognized, the death penalty’s
penological rationale in fact rests almost exclusively upon
a belief in its tendency to deter and upon its ability to
satisfy a community’s interest in retribution. See, e.g.,
Gregg, 428 U. S., at 183 (joint opinion of Stewart, Powell,
and Stevens, JJ.). Many studies have examined the death
penalty’s deterrent effect; some have found such an effect,
whereas others have found a lack of evidence that it deters
crime. Compare ante, at 5 (SCALIA, J., concurring) (collect­
ing studies finding deterrent effect), with e.g., Sorensen,
Wrinkle, Brewer, & Marquart, Capital Punishment and
Deterrence: Examining the Effect of Executions on Murder
in Texas, 45 Crime & Delinquency 481 (1999) (no evidence
of a deterrent effect); Bonner & Fessenden, Absence of
Executions: A Special Report, States With No Death Pen­
alty Share Lower Homicide Rates, N. Y. Times, Sept. 22,
2000, p. A1 (from 1980–2000, homicide rate in death-
penalty States was 48% to 101% higher than in non-death­
penalty States); Radelet & Akers, Deterrence and the
Death Penalty: The Views of the Experts, 87 J. Crim. L. &
C. 1, 8 (1996) (over 80% of criminologists believe existing
research fails to support deterrence justification); Donohue
& Wolfers, Uses and Abuses of Empirical Evidence in the
Death Penalty Debate, 58 Stan. L. Rev. 791, 794 (2005)
(evaluating existing statistical evidence and concluding
that there is “profound uncertainty” about the existence of
a deterrent effect).
   Recently, the National Research Council (whose mem­
bers are drawn from the councils of the National Academy
of Sciences, the National Academy of Engineering, and the
                  Cite as: 576 U. S. ____ (2015)            25

                     BREYER, J., dissenting

Institute of Medicine) reviewed 30 years of empirical
evidence and concluded that it was insufficient to estab­
lish a deterrent effect and thus should “not be used to
inform” discussion about the deterrent value of the death
penalty. National Research Council, Deterrence and the
Death Penalty 2 (D. Nagin & J. Pepper eds. 2012); accord,
Baze v. Rees, 553 U. S. 35, 79 (2008) (Stevens, J., concur­
ring in judgment) (“Despite 30 years of empirical re-
search in the area, there remains no reliable statistical evi­

dence that capital punishment in fact deters potential
offenders”).
   I recognize that a “lack of evidence” for a proposition
does not prove the contrary. See Ring, supra, at 615 (one
might believe the studies “inconclusive”). But suppose
that we add to these studies the fact that, today, very few
of those sentenced to death are actually executed, and that
even those executions occur, on average, after nearly two
decades on death row. DPIC, Execution List 2014, supra.
Then, does it still seem likely that the death penalty has a
significant deterrent effect?
   Consider, for example, what actually happened to the
183 inmates sentenced to death in 1978. As of 2013 (35
years later), 38 (or 21% of them) had been executed; 132
(or 72%) had had their convictions or sentences overturned
or commuted; and 7 (or 4%) had died of other (likely natu­
ral) causes. Six (or 3%) remained on death row. BJS 2013
Stats, at 19 (Table 16).
   The example illustrates a general trend. Of the 8,466
inmates under a death sentence at some point between
1973 and 2013, 16% were executed, 42% had their convic­
tions or sentences overturned or commuted, and 6% died
by other causes; the remainder (35%) are still on death
row. Id., at 20 (Table 17); see also Baumgartner & Die­
trich, Most Death Penalty Sentences Are Overturned:
Here’s Why That Matters, Washington Post Blog, Monkey
Cage, Mar. 17, 2015 (similar).
26                    GLOSSIP v. GROSS

                     BREYER, J., dissenting

   Thus an offender who is sentenced to death is two or
three times more likely to find his sentence overturned or
commuted than to be executed; and he has a good chance
of dying from natural causes before any execution (or
exoneration) can take place. In a word, executions are
rare. And an individual contemplating a crime but evalu­
ating the potential punishment would know that, in any
event, he faces a potential sentence of life without parole.
   These facts, when recurring, must have some offsetting
effect on a potential perpetrator’s fear of a death penalty.
And, even if that effect is no more than slight, it makes it
difficult to believe (given the studies of deterrence cited
earlier) that such a rare event significantly deters horren­
dous crimes. See Furman, 408 U. S., at 311–312 (White,
J., concurring) (It cannot “be said with confidence that
society’s need for specific deterrence justifies death for so
few when for so many in like circumstances life imprison­
ment or shorter prison terms are judged sufficient”).
   But what about retribution? Retribution is a valid
penological goal. I recognize that surviving relatives of
victims of a horrendous crime, or perhaps the community
itself, may find vindication in an execution. And a com­
munity that favors the death penalty has an understand-
able interest in representing their voices. But see A. Sarat,
Mercy on Trial: What It Means To Stop an Execution 130
(2005) (Illinois Governor George Ryan explained his deci­
sion to commute all death sentences on the ground that it
was “cruel and unusual” for “family members to go
through this . . . legal limbo for [20] years”).
   The relevant question here, however, is whether a
“community’s sense of retribution” can often find vindica­
tion in “a death that comes,” if at all, “only several decades
after the crime was committed.” Valle v. Florida, 564
U. S. ___, ___ (2011) (BREYER, J., dissenting from denial of
stay) (slip op., at 3). By then the community is a different
group of people. The offenders and the victims’ families
                  Cite as: 576 U. S. ____ (2015)           27

                     BREYER, J., dissenting

have grown far older. Feelings of outrage may have sub­
sided. The offender may have found himself a changed
human being. And sometimes repentance and even for­
giveness can restore meaning to lives once ruined. At the
same time, the community and victims’ families will know
that, even without a further death, the offender will serve
decades in prison under a sentence of life without parole.
  I recognize, of course, that this may not always be the
case, and that sometimes the community believes that an
execution could provide closure. Nevertheless, the delays
and low probability of execution must play some role in
any calculation that leads a community to insist on death
as retribution. As I have already suggested, they may well
attenuate the community’s interest in retribution to the
point where it cannot by itself amount to a significant
justification for the death penalty. Id., at ___ (slip op., at
3). In any event, I believe that whatever interest in retri­
bution might be served by the death penalty as currently
administered, that interest can be served almost as well
by a sentence of life in prison without parole (a sentence
that every State now permits, see ACLU, A Living Death:
Life Without Parole for Nonviolent Offenses 11, and n. 10
(2013)).
  Finally, the fact of lengthy delays undermines any effort
to justify the death penalty in terms of its prevalence
when the Founders wrote the Eighth Amendment. When
the Founders wrote the Constitution, there were no 20- or
30-year delays. Execution took place soon after sentenc­
ing. See P. Mackey, Hanging in the Balance: The Anti-
Capital Punishment Movement in New York State, 1776–
1861, p. 17 (1982); T. Jefferson, A Bill for Proportioning
Crimes and Punishments (1779), reprinted in The Com­
plete Jefferson 90, 95 (S. Padover ed. 1943); 2 Papers of
John Marshall 207–209 (C. Cullen & H. Johnson eds.
1977) (describing petition for commutation based in part
on 5-month delay); Pratt v. Attorney Gen. of Jamaica,
28                   GLOSSIP v. GROSS

                    BREYER, J., dissenting

[1994] 2 A. C., at 17 (same in United Kingdom) (collecting
cases). And, for reasons I shall describe, infra, at 29–33,
we cannot return to the quick executions in the founding
era.
                               3
   The upshot is that lengthy delays both aggravate the
cruelty of the death penalty and undermine its jurispru­
dential rationale. And this Court has said that, if the
death penalty does not fulfill the goals of deterrence or
retribution, “it is nothing more than the purposeless and
needless imposition of pain and suffering and hence an
unconstitutional punishment.” Atkins, 536 U. S., at 319
(quoting Enmund v. Florida, 458 U. S. 782, 798 (1982);
internal quotation marks omitted); see also Gregg, 428
U. S., at 183 (joint opinion of Stewart, Powell, and Ste­
vens, JJ.) (“sanction imposed cannot be so totally without
penological justification that it results in the gratuitous
infliction of suffering”); Furman, supra, at 312 (White, J.,
concurring) (a “penalty with such negligible returns to the
State would be patently excessive and cruel and unusual
punishment violative of the Eighth Amendment”); Thomp­
son, 556 U. S., at 1115 (statement of Stevens, J., respect­
ing denial of certiorari) (similar).
   Indeed, Justice Lewis Powell (who provided a crucial
vote in Gregg) came to much the same conclusion, albeit
after his retirement from this Court. Justice Powell had
come to the Court convinced that the Federal Constitution
did not outlaw the death penalty but rather left the matter
up to individual States to determine. Furman, supra, at
431–432 (Powell, J., dissenting); see also J. Jeffries, Jus­
tice Lewis F. Powell, Jr., p. 409 (2001) (describing Powell,
during his time on the Court, as a “fervent partisan” of
“the constitutionality of capital punishment”).
   Soon after Justice Powell’s retirement, Chief Justice
Rehnquist appointed him to chair a committee addressing
                 Cite as: 576 U. S. ____ (2015)           29

                     BREYER, J., dissenting

concerns about delays in capital cases, the Ad Hoc Com­
mittee on Federal Habeas Corpus in Capital Cases (Com­
mittee). The Committee presented a report to Congress,
and Justice Powell testified that “[d]elay robs the penalty
of much of its deterrent value.” Habeas Corpus Reform,
Hearings before the Senate Committee on the Judiciary,
100th Cong., 1st and 2d Sess., 35 (1989 and 1990). Justice
Powell, according to his official biographer, ultimately
concluded that capital punishment:
    “ ‘serves no useful purpose.’ The United States was
    ‘unique among the industrialized nations of the West
    in maintaining the death penalty,’ and it was enforced
    so rarely that it could not deter. More important, the
    haggling and delay and seemingly endless litigation in
    every capital case brought the law itself into disre­
    pute.” Jeffries, supra, at 452.
In short, the problem of excessive delays led Justice Pow­
ell, at least in part, to conclude that the death penalty was
unconstitutional.
   As I have said, today delays are much worse. When
Chief Justice Rehnquist appointed Justice Powell to the
Committee, the average delay between sentencing and
execution was 7 years and 11 months, compared with 17
years and 7 months today. Compare BJS, L. Greenfeld,
Capital Punishment, 1990, p. 11 (Table 12) (Sept. 1991)
with supra, at 18–19.
                             C
  One might ask, why can Congress or the States not deal
directly with the delay problem? Why can they not take
steps to shorten the time between sentence and execution,
and thereby mitigate the problems just raised? The an­
swer is that shortening delay is much more difficult than
one might think. And that is in part because efforts to do
so risk causing procedural harms that also undermine the
30                   GLOSSIP v. GROSS

                     BREYER, J., dissenting

death penalty’s constitutionality.
   For one thing, delays have helped to make application of
the death penalty more reliable. Recall the case of Henry
Lee McCollum, whom DNA evidence exonerated 30 years
after his conviction. Katz & Eckholm, N. Y. Times, at A1.
If McCollum had been executed earlier, he would not have
lived to see the day when DNA evidence exonerated him
and implicated another man; that man is already serving
a life sentence for a rape and murder that he committed
just a few weeks after the murder McCollum was convicted
of. Ibid. In fact, this Court had earlier denied review
of McCollum’s claim over the public dissent of only one
Justice. McCollum v. North Carolina, 512 U. S. 1254
(1994). And yet a full 20 years after the Court denied
review, McCollum was exonerated by DNA evidence.
There are a significant number of similar cases, some of
which I have discussed earlier. See also DPIC Innocence
List, supra (Nathson Fields, 23 years; Paul House, 23
years; Nicholas Yarris, 21 years; Anthony Graves, 16
years; Damon Thibodeaux, 15 years; Ricky Jackson, Wiley
Bridgeman, and Kwame Ajamu, all exonerated for the
same crime 39 years after their convictions).
   In addition to those who are exonerated on the ground
that they are innocent, there are other individuals whose
sentences or convictions have been overturned for other
reasons (as discussed above, state and federal courts found
error in 68% of the capital cases they reviewed between
1973 and 1995). See Part I, supra. In many of these
cases, a court will have found that the individual did not
merit the death penalty in a special sense—namely, he
failed to receive all the procedural protections that the law
requires for the death penalty’s application. By eliminat­
ing some of these protections, one likely could reduce
delay.     But which protections should we eliminate?
Should we eliminate the trial-related protections we have
established for capital defendants: that they be able to
                  Cite as: 576 U. S. ____ (2015)             31

                      BREYER, J., dissenting

present to the sentencing judge or jury all mitigating
circumstances, Lockett v. Ohio, 438 U. S. 586; that the
State provide guidance adequate to reserve the application
of the death penalty to particularly serious murders,
Gregg, 428 U. S. 153; that the State provide adequate
counsel and, where warranted, adequate expert assis­
tance, Powell v. Alabama, 287 U. S. 45 (1932); Wiggins v.
Smith, 539 U. S. 510 (2003); Ake v. Oklahoma, 470 U. S.
68 (1985); or that a jury must find the aggravating factors
necessary to impose the death penalty, Ring, 536 U. S.
584; see also id., at 614 (BREYER, J., concurring in judg­
ment)? Should we no longer ensure that the State does
not execute those who are seriously intellectually disabled,
Atkins, 536 U. S. 304? Should we eliminate the require­
ment that the manner of execution be constitutional, Baze,
553 U. S. 35, or the requirement that the inmate be men­
tally competent at the time of his execution, Ford v.
Wainwright, 477 U. S. 399 (1986)? Or should we get rid of
the criminal protections that all criminal defendants
receive—for instance, that defendants claiming violation
of constitutional guarantees (say “due process of law”) may
seek a writ of habeas corpus in federal courts? See, e.g.,
O’Neal v. McAninch, 513 U. S. 432 (1995). My answer to
these questions is “surely not.” But see ante, at 5–7
(SCALIA, J., concurring).
   One might, of course, argue that courts, particularly
federal courts providing additional layers of review, apply
these and other requirements too strictly, and that causes
delay. But, it is difficult for judges, as it would be difficult
for anyone, not to apply legal requirements punctiliously
when the consequence of failing to do so may well be
death, particularly the death of an innocent person. See,
e.g., Zant v. Stephens, 462 U. S. 862, 885 (1983)
(“[A]lthough not every imperfection in the deliberative
process is sufficient, even in a capital case, to set aside a
state-court judgment, the severity of the sentence man­
32                   GLOSSIP v. GROSS

                     BREYER, J., dissenting

dates careful scrutiny in the review of any colorable claim
of error”); Kyles v. Whitley, 514 U. S. 419, 422 (1995)
(“[O]ur duty to search for constitutional error with pains­
taking care is never more exacting than it is in a capital
case” (internal quotation marks omitted)); Thompson, 556
U. S., at 1116 (statement of Stevens, J.) (“Judicial process
takes time, but the error rate in capital cases illustrates
its necessity”).
   Moreover, review by courts at every level helps to en­
sure reliability; if this Court had not ordered that Anthony
Ray Hinton receive further hearings in state court, see
Hinton v. Alabama, 571 U. S. ___, he may well have been
executed rather than exonerated. In my own view, our
legal system’s complexity, our federal system with its
separate state and federal courts, our constitutional guar­
antees, our commitment to fair procedure, and, above all,
a special need for reliability and fairness in capital cases,
combine to make significant procedural “reform” unlikely
in practice to reduce delays to an acceptable level.
   And that fact creates a dilemma: A death penalty sys­
tem that seeks procedural fairness and reliability brings
with it delays that severely aggravate the cruelty of capi­
tal punishment and significantly undermine the rationale
for imposing a sentence of death in the first place. See
Knight, 528 U. S., at 998 (BREYER, J., dissenting from
denial of certiorari) (one of the primary causes of the delay
is the States’ “failure to apply constitutionally sufficient
procedures at the time of initial [conviction or] sentenc­
ing”). But a death penalty system that minimizes delays
would undermine the legal system’s efforts to secure relia­
bility and procedural fairness.
   In this world, or at least in this Nation, we can have a
death penalty that at least arguably serves legitimate
penological purposes or we can have a procedural system
that at least arguably seeks reliability and fairness in the
death penalty’s application. We cannot have both. And
                  Cite as: 576 U. S. ____ (2015)           33

                     BREYER, J., dissenting

that simple fact, demonstrated convincingly over the past
40 years, strongly supports the claim that the death pen­
alty violates the Eighth Amendment. A death penalty
system that is unreliable or procedurally unfair would
violate the Eighth Amendment. Woodson, 428 U. S., at
305 (plurality opinion); Hall, 572 U. S., at ___ (slip op., at
22); Roper, 543 U. S., at 568. And so would a system that,
if reliable and fair in its application of the death penalty,
would serve no legitimate penological purpose. Furman,
408 U. S., at 312 (White, J., concurring); Gregg, supra, at
183 (joint opinion of Stewart, Powell, and Stevens, JJ.);
Atkins, supra, at 319.
                             IV
      “Unusual”—Decline in Use of the Death Penalty
   The Eighth Amendment forbids punishments that are
cruel and unusual. Last year, in 2014, only seven States
carried out an execution. Perhaps more importantly, in
the last two decades, the imposition and implementation
of the death penalty have increasingly become unusual. I
can illustrate the significant decline in the use of the
death penalty in several ways.
   An appropriate starting point concerns the trajectory of
the number of annual death sentences nationwide, from
the 1970’s to present day. In 1977—just after the Su­
preme Court made clear that, by modifying their legisla­
tion, States could reinstate the death penalty—137 people
were sentenced to death. BJS 2013 Stats, at 19 (Table 16).
Many States having revised their death penalty laws to
meet Furman’s requirements, the number of death sen­
tences then increased. Between 1986 and 1999, 286 per­
sons on average were sentenced to death each year. BJS
2013 Stats, at 14, 19 (Tables 11 and 16). But, approxi­
mately 15 years ago, the numbers began to decline, and
they have declined rapidly ever since. See Appendix A,
infra (showing sentences from 1977–2014). In 1999, 279
34                   GLOSSIP v. GROSS

                    BREYER, J., dissenting

persons were sentenced to death. BJS 2013 Stats, at 19
(Table 16). Last year, just 73 persons were sentenced to
death. DPIC, The Death Penalty in 2014: Year End Re­
port 1 (2015).
  That trend, a significant decline in the last 15 years,
also holds true with respect to the number of annual
executions. See Appendix B, infra (showing executions
from 1977–2014). In 1999, 98 people were executed. BJS,
Data Collection: National Prisoner Statistics Program
(BJS Prisoner Statistics) (available in Clerk of Court’s
case file). Last year, that number was only 35. DPIC, The
Death Penalty in 2014, supra, at 1.
  Next, one can consider state-level data. Often when
deciding whether a punishment practice is, constitutionally
speaking, “unusual,” this Court has looked to the num-
ber of States engaging in that practice. Atkins, 536 U. S.,
at 313–316; Roper, supra, at 564–566. In this respect, the
number of active death penalty States has fallen dramati­
cally. In 1972, when the Court decided Furman, the death
penalty was lawful in 41 States. Nine States had abol­
ished it. E. Mandery, A Wild Justice: The Death and
Resurrection of Capital Punishment in America 145
(2013). As of today, 19 States have abolished the death
penalty (along with the District of Columbia), although
some did so prospectively only. See DPIC, States With
and Without the Death Penalty, online at http://www.
deathpenaltyinfo.org/states-and-without-death-penalty. In
11 other States that maintain the death penalty on the
books, no execution has taken place for more than eight
years: Arkansas (last execution 2005); California (2006);
Colorado (1997); Kansas (no executions since the death
penalty was reinstated in 1976); Montana (2006); Nevada
(2006); New Hampshire (no executions since the death
penalty was reinstated in 1976); North Carolina (2006);
Oregon (1997); Pennsylvania (1999); and Wyoming (1992).
DPIC, Executions by State and Year, online at http://www.
                 Cite as: 576 U. S. ____ (2015)          35

                    BREYER, J., dissenting

deathpenaltyinfo.org/node/5741.
   Accordingly, 30 States have either formally abolished
the death penalty or have not conducted an execution in
more than eight years. Of the 20 States that have con­
ducted at least one execution in the past eight years, 9
have conducted fewer than five in that time, making an
execution in those States a fairly rare event. BJS Prisoner
Statistics (Delaware, Idaho, Indiana, Kentucky, Louisiana,
South Dakota, Tennessee, Utah, Washington).            That
leaves 11 States in which it is fair to say that capital
punishment is not “unusual.” And just three of those
States (Texas, Missouri, and Florida) accounted for 80% of
the executions nationwide (28 of the 35) in 2014. See
DPIC, Number of Executions by State and Region Since
1976, online at http://www.deathpenaltyinfo.org/number­

executions-state-and-region-1976. Indeed, last year, only
seven States conducted an execution. DPIC, Executions
by State and Year, supra; DPIC, Death Sentences in the
United States From 1977 by State and by Year, online at
http://www.deathpenaltyinfo.org/death-sentences-united­
states-1977-2008. In other words, in 43 States, no one was
executed.
   In terms of population, if we ask how many Americans
live in a State that at least occasionally carries out an
execution (at least one within the prior three years), the
answer two decades ago was 60% or 70%. Today, that
number is 33%. See Appendix C, infra.
   At the same time, use of the death penalty has become
increasingly concentrated geographically.       County-by­
county figures are relevant, for decisions to impose the
death penalty typically take place at a county level. See
supra, at 12–13. County-level sentencing figures show
that, between 1973 and 1997, 66 of America’s 3,143 coun­
ties accounted for approximately 50% of all death sentences
imposed. Liebman & Clarke 264–265; cf. id., at 266.
(counties with 10% of the Nation’s population imposed
36                   GLOSSIP v. GROSS

                    BREYER, J., dissenting

43% of its death sentences). By the early 2000’s, the death
penalty was only actively practiced in a very small number
of counties: between 2004 and 2009, only 35 counties
imposed 5 or more death sentences, i.e., approximately one
per year. See Appendix D, infra (such counties colored in
red) (citing Ford, The Death Penalty’s Last Stand, The
Atlantic, Apr. 21, 2015). And more recent data show that
the practice has diminished yet further: between 2010 and
2015 (as of June 22), only 15 counties imposed five or more
death sentences. See Appendix E, infra. In short, the
number of active death penalty counties is small and
getting smaller. And the overall statistics on county-level
executions bear this out. Between 1976 and 2007, there
were no executions in 86% of America’s counties. Liebman
& Clarke 265–266, and n. 47; cf. ibid. (counties with less
than 5% of the Nation’s population carried out over half of
its executions from 1976–2007).
   In sum, if we look to States, in more than 60% there is
effectively no death penalty, in an additional 18% an
execution is rare and unusual, and 6%, i.e., three States,
account for 80% of all executions. If we look to population,
about 66% of the Nation lives in a State that has not
carried out an execution in the last three years. And if we
look to counties, in 86% there is effectively no death pen-
alty. It seems fair to say that it is now unusual to find
capital punishment in the United States, at least when we
consider the Nation as a whole. See Furman, 408 U. S., at
311 (1972) (White, J., concurring) (executions could be so
infrequently carried out that they “would cease to be a
credible deterrent or measurably to contribute to any
other end of punishment in the criminal justice system . . .
when imposition of the penalty reaches a certain degree
of infrequency, it would be very doubtful that any exist-
ing general need for retribution would be measurably
satisfied”).
   Moreover, we have said that it “ ‘is not so much the
                 Cite as: 576 U. S. ____ (2015)          37

                    BREYER, J., dissenting

number of these States that is significant, but the con­
sistency of the direction of change.’ ” Roper, 543 U. S., at
566 (quoting Atkins, supra, at 315) (finding significant
that five States had abandoned the death penalty for
juveniles, four legislatively and one judicially, since the
Court’s decision in Stanford v. Kentucky, 492 U. S. 361
(1989)). Judged in that way, capital punishment has
indeed become unusual. Seven States have abolished the
death penalty in the last decade, including (quite recently)
Nebraska. DPIC, States With and Without the Death
Penalty, supra. And several States have come within a
single vote of eliminating the death penalty. Seelye,
Measure to Repeal Death Penalty Fails by a Single Vote in
New Hampshire Senate, N. Y. Times, Apr. 17, 2014, p.
A12; Dennison, House Deadlocks on Bill To Abolish Death
Penalty in Montana, Billings Gazette, Feb. 23, 2015; see
also Offredo, Delaware Senate Passes Death Penalty
Repeal Bill, Delaware News Journal, Apr. 3, 2015. Eleven
States, as noted earlier, have not executed anyone in eight
years. Supra, at 34–35. And several States have formally
stopped executing inmates. See Yardley, Oregon’s Gover­
nor Says He Will Not Allow Executions, N. Y. Times, Nov.
23, 2011, p. A14 (Oregon); Governor of Colorado, Exec.
Order No. D2013–006, May 22, 2013 (Colorado); Lovett,
Executions Are Suspended by Governor in Washington,
N. Y. Times, Feb. 12, 2014, p. A12 (Washington); Begley,
Pennsylvania Stops Using the Death Penalty, Time, Feb.
13, 2015 (Pennsylvania); see also Welsh-Huggins, Associ­
ated Press, Ohio Executions Rescheduled, Jan. 30, 2015
(Ohio).
  Moreover, the direction of change is consistent. In the
past two decades, no State without a death penalty has
passed legislation to reinstate the penalty. See Atkins,
supra, at 315–316; DPIC, States With and Without the
Death Penalty, supra. Indeed, even in many States most
associated with the death penalty, remarkable shifts have
38                   GLOSSIP v. GROSS

                    BREYER, J., dissenting

occurred. In Texas, the State that carries out the most
executions, the number of executions fell from 40 in 2000
to 10 in 2014, and the number of death sentences fell from
48 in 1999 to 9 in 2013 (and 0 thus far in 2015). DPIC,
Executions by State and Year, supra; BJS, T. Snell, Capi­
tal Punishment, 1999, p. 6 (Table 5) (Dec. 2000) (hereinaf­
ter BJS 1999 Stats); BJS 2013 Stats, at 19 (Table 16); von
Drehle, Bungled Executions, Backlogged Courts, and
Three More Reasons the Modern Death Penalty Is a
Failed Experiment, Time, June 8, 2015, p. 26. Similarly
dramatic declines are present in Virginia, Oklahoma,
Missouri, and North Carolina. BJS 1999 Stats, at 6 (Table
5); BJS 2013 Stats, at 19 (Table 16).
  These circumstances perhaps reflect the fact that a
majority of Americans, when asked to choose between the
death penalty and life in prison without parole, now
choose the latter. Wilson, Support for Death Penalty Still
High, But Down, Washington Post, GovBeat, June 5, 2014,
online at www.washingtonpost.com/blogs/govbeat/wp/
2014/06/05/support-for-death-penalty-still-high-but-down;
see also ALI, Report of the Council to the Membership on
the Matter of the Death Penalty 4 (Apr. 15, 2009) (with­
drawing Model Penal Code section on capital punishment
section from the Code, in part because of doubts that the
American Law Institute could “recommend procedures
that would” address concerns about the administration of
the death penalty); cf. Gregg, 428 U. S., at 193–194 (joint
opinion of Stewart, Powell, and Stevens, JJ.) (relying in
part on Model Penal Code to conclude that a “carefully
drafted statute” can satisfy the arbitrariness concerns
expressed in Furman).
  I rely primarily upon domestic, not foreign events, in
pointing to changes and circumstances that tend to justify
the claim that the death penalty, constitutionally speak­
ing, is “unusual.” Those circumstances are sufficient to
warrant our reconsideration of the death penalty’s consti­
                 Cite as: 576 U. S. ____ (2015)           39

                     BREYER, J., dissenting

tutionality. I note, however, that many nations—indeed,
95 of the 193 members of the United Nations—have for­
mally abolished the death penalty and an additional 42
have abolished it in practice. Oakford, UN Vote Against
Death Penalty Highlights Global Abolitionist Trend–and
Leaves the US Stranded, Vice News, Dec. 19, 2014, online
at https: / /news.vice.com / article / un-vote-against-death-
penalty-highlights-global-abolitionist-trend-and-leaves-the­

us-stranded. In 2013, only 22 countries in the world car­
ried out an execution. International Commission Against
Death Penalty, Review 2013, pp. 2–3. No executions were
carried out in Europe or Central Asia, and the United
States was the only country in the Americas to execute an
inmate in 2013. Id., at 3. Only eight countries executed
more than 10 individuals (the United States, China, Iran,
Iraq, Saudi Arabia, Somalia, Sudan, Yemen). Id., at 2.
And almost 80% of all known executions took place in
three countries: Iran, Iraq, and Saudi Arabia. Amnesty
International, Death Sentences and Executions 2013, p. 3
(2014). (This figure does not include China, which has a
large population, but where precise data cannot be ob­
tained. Id., at 2.)
                             V
  I recognize a strong counterargument that favors consti­
tutionality. We are a court. Why should we not leave the
matter up to the people acting democratically through
legislatures? The Constitution foresees a country that will
make most important decisions democratically. Most
nations that have abandoned the death penalty have done
so through legislation, not judicial decision. And legisla­
tors, unlike judges, are free to take account of matters
such as monetary costs, which I do not claim are relevant
here. See, e.g., Berman, Nebraska Lawmakers Abolish the
Death Penalty, Narrowly Overriding Governor’s Veto,
Washington Post Blog, Post Nation, May 27, 2015) (listing
40                   GLOSSIP v. GROSS

                     BREYER, J.,
                    BREYER,   J.,dissenting
                                  dissenting

cost as one of the reasons why Nebraska legislators re­
cently repealed the death penalty in that State); cf. Cali­
fornia Commission on the Fair Administration of Justice,
Report and Recommendations on the Administration of
the Death Penalty in California 117 (June 30, 2008) (death
penalty costs California $137 million per year; a compara­
ble system of life imprisonment without parole would cost
$11.5 million per year), online at http://www.ccfaj.org/rr­
dp-official.html; Dáte, The High Price of Killing Killers,
Palm Beach Post, Jan. 4, 2000, p. 1A (cost of each execu­
tion is $23 million above cost of life imprisonment without
parole in Florida).
   The answer is that the matters I have discussed, such as
lack of reliability, the arbitrary application of a serious
and irreversible punishment, individual suffering caused
by long delays, and lack of penological purpose are quin­
tessentially judicial matters. They concern the infliction—
indeed the unfair, cruel, and unusual infliction—of a
serious punishment upon an individual. I recognize that
in 1972 this Court, in a sense, turned to Congress and the
state legislatures in its search for standards that would
increase the fairness and reliability of imposing a death
penalty. The legislatures responded. But, in the last four
decades, considerable evidence has accumulated that
those responses have not worked.
   Thus we are left with a judicial responsibility. The
Eighth Amendment sets forth the relevant law, and we
must interpret that law. See Marbury v. Madison, 1
Cranch 137, 177 (1803); Hall, 572 U. S., at ___ (slip op., at
19) (“That exercise of independent judgment is the Court’s
judicial duty”). We have made clear that “ ‘the Constitu­
tion contemplates that in the end our own judgment will
be brought to bear on the question of the acceptability of
the death penalty under the Eighth Amendment.’ ” Id., at
___ (slip op., at 19) (quoting Coker v. Georgia, 433 U. S.
584, 597 (1977) (plurality opinion)); see also Thompson v.
                  Cite as: 576 U. S. ____ (2015)           41

                     BREYER, J., dissenting

Oklahoma, 487 U. S. 815, 833, n. 40 (1988) (plurality
opinion).
   For the reasons I have set forth in this opinion, I believe
it highly likely that the death penalty violates the Eighth
Amendment. At the very least, the Court should call for
full briefing on the basic question.
   With respect, I dissent.
42              GLOSSIP v. GROSS



        Appendix A to ,opinion
             BREYER     J., dissenting
                                of BREYER, J. 


                 APPENDICES 

                      A

     Death Sentences Imposed 1977–2014 

   Cite as: 576 U. S. ____ (2015)       43

Appendix B to ,opinion
     BREYER     J., dissenting
                        of BREYER, J.



             B

    Executions 1977–2014 

44                   GLOSSIP v. GROSS

              Appendix C to ,opinion
                   BREYER     J., dissenting
                                      of BREYER, J.



                             C
Percentage of U.S. population in States that conducted an
execution within prior 3 years

                 Year                 Percentage
                 1994                    54%
                 1995                    60%
                 1996                    63%
                 1997                    63%
                 1998                    61%
                 1999                    70%
                 2000                    68%
                 2001                    67%
                 2002                    57%
                 2003                    53%
                 2004                    52%
                 2005                    52%
                 2006                    55%
                 2007                    57%
                 2008                    53%
                 2009                    39%
                 2010                    43%
                 2011                    42%
                 2012                    39%
                 2013                    34%
                 2014                    33%
                 Cite as: 576 U. S. ____ (2015)            1

                   SOTOMAYOR, J., dissenting

SUPREME COURT OF THE UNITED STATES
                         _________________

                         No. 14–7955
                         _________________


    RICHARD E. GLOSSIP, ET AL., PETITIONERS v.


             KEVIN J. GROSS, ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE TENTH CIRCUIT


                        [June 29, 2015] 


   JUSTICE SOTOMAYOR, with whom JUSTICE GINSBURG,
JUSTICE BREYER, and JUSTICE KAGAN join, dissenting.
   Petitioners, three inmates on Oklahoma’s death row,
challenge the constitutionality of the State’s lethal injec­
tion protocol. The State plans to execute petitioners using
three drugs: midazolam, rocuronium bromide, and potas­
sium chloride. The latter two drugs are intended to para­
lyze the inmate and stop his heart. But they do so in a
torturous manner, causing burning, searing pain. It is
thus critical that the first drug, midazolam, do what it is
supposed to do, which is to render and keep the inmate
unconscious. Petitioners claim that midazolam cannot be
expected to perform that function, and they have presented
ample evidence showing that the State’s planned use of
this drug poses substantial, constitutionally intolerable
risks.
   Nevertheless, the Court today turns aside petitioners’
plea that they at least be allowed a stay of execution while
they seek to prove midazolam’s inadequacy. The Court
achieves this result in two ways: first, by deferring to the
District Court’s decision to credit the scientifically unsup­
ported and implausible testimony of a single expert wit­
ness; and second, by faulting petitioners for failing to
satisfy the wholly novel requirement of proving the avail­
ability of an alternative means for their own executions.
2                    GLOSSIP v. GROSS

                   SOTOMAYOR, J., dissenting

On both counts the Court errs. As a result, it leaves peti­
tioners exposed to what may well be the chemical equiva­
lent of being burned at the stake.
                                I

                               A

   The Eighth Amendment succinctly prohibits the inflic­
tion of “cruel and unusual punishments.” Seven years ago,
in Baze v. Rees, 553 U. S. 35 (2008), the Court addressed
the application of this mandate to Kentucky’s lethal injec­
tion protocol. At that time, Kentucky, like at least 29 of
the 35 other States with the death penalty, utilized a
series of three drugs to perform executions: (1) sodium
thiopental, a “fast-acting barbiturate sedative that induces
a deep, comalike unconsciousness when given in the
amounts used for lethal injection”; (2) pancuronium bro­
mide, “a paralytic agent that inhibits all muscular-skeletal
movements and . . . stops respiration”; and (3) potassium
chloride, which “interferes with the electrical signals that
stimulate the contractions of the heart, inducing cardiac
arrest.” Id., at 44 (plurality opinion of ROBERTS, C. J.).
   In Baze, it was undisputed that absent a “proper dose of
sodium thiopental,” there would be a “substantial, consti­
tutionally unacceptable risk of suffocation from the admin­
istration of pancuronium bromide and pain from the injec­
tion of potassium chloride.” Id., at 53. That is because, if
given to a conscious inmate, pancuronium bromide would
leave him or her asphyxiated and unable to demonstrate
“any outward sign of distress,” while potassium chloride
would cause “excruciating pain.” Id., at 71 (Stevens, J.,
concurring in judgment). But the Baze petitioners conceded
that if administered as intended, Kentucky’s method of
execution would nevertheless “result in a humane death,”
id., at 41 (plurality opinion), as the “proper administra­
tion” of sodium thiopental “eliminates any meaningful risk
that a prisoner would experience pain from the subse­
                 Cite as: 576 U. S. ____ (2015)           3

                   SOTOMAYOR, J., dissenting

quent injections of pancuronium and potassium chloride,”
id., at 49. Based on that premise, the Court ultimately
rejected the challenge to Kentucky’s protocol, with the
plurality opinion concluding that the State’s procedures
for administering these three drugs ensured there was no
“objectively intolerable risk” of severe pain. Id., at 61–62
(internal quotation marks omitted).
                              B
  For many years, Oklahoma performed executions using
the same three drugs at issue in Baze. After Baze was
decided, however, the primary producer of sodium thio­
pental refused to continue permitting the drug to be used
in executions. Ante, at 4–5. Like a number of other
States, Oklahoma opted to substitute pentobarbital, an­
other barbiturate, in its place. But in March 2014, shortly
before two scheduled executions, Oklahoma found itself
unable to secure this drug. App. 144.
  The State rescheduled the executions for the following
month to give it time to locate an alternative anesthetic.
In less than a week, a group of officials from the Okla-
homa Department of Corrections and the Attorney General’s
office selected midazolam to serve as a replacement for
pentobarbital. Id., at 145, 148–149.
  Soon thereafter, Oklahoma used midazolam for the first
time in its execution of Clayton Lockett. That execution
did not go smoothly. Ten minutes after an intravenous
(IV) line was set in Lockett’s groin area and 100 milli­
grams of midazolam were administered, an attending
physician declared Lockett unconscious. Id., at 392–393.
When the paralytic and potassium chloride were adminis­
tered, however, Lockett awoke. Ibid. Various witnesses
reported that Lockett began to writhe against his re­
straints, saying, “[t]his s*** is f***ing with my mind,”
“something is wrong,” and “[t]he drugs aren’t working.”
Id., at 53 (internal quotation marks omitted). State offi­
4                    GLOSSIP v. GROSS

                   SOTOMAYOR, J., dissenting

cials ordered the blinds lowered, then halted the execu­
tion.    Id., at 393, 395.       But 10 minutes later—
approximately 40 minutes after the execution began—
Lockett was pronounced dead. Id., at 395.
   The State stayed all future executions while it sought to
determine what had gone wrong in Lockett’s. Five months
later, the State released an investigative report identify­
ing a flaw in the IV line as the principal difficulty: The IV
had failed to fully deliver the lethal drugs into Lockett’s
veins. Id., at 398. An autopsy determined, however, that
the concentration of midazolam in Lockett’s blood was
more than sufficient to render an average person uncon­
scious. Id., at 397, 405.
   In response to this report, the State modified its lethal
injection protocol. The new protocol contains a number of
procedures designed to guarantee that members of the
execution team are able to insert the IV properly, and
charges them with ensuring that the inmate is uncon­
scious. Id., at 57–66, 361–369. But the protocol continues
to authorize the use of the same three-drug formula used
to kill Lockett—though it does increase the intended dose
of midazolam from 100 milligrams to 500 milligrams. Id.,
at 61. The State has indicated that it plans to use this
drug combination in all upcoming executions, subject to
only an immaterial substitution of paralytic agents. Ante,
at 7–8.
                            C
  In June 2014, inmates on Oklahoma’s death row filed a
42 U. S. C. §1983 suit against respondent prison officials
challenging the constitutionality of Oklahoma’s method of
execution. After the State released its revised execution
protocol, the four inmates whose executions were most
imminent—Charles Warner, along with petitioners Rich­
ard Glossip, John Grant, and Benjamin Cole—moved for a
preliminary injunction. They contended, among other
                 Cite as: 576 U. S. ____ (2015)            5

                   SOTOMAYOR, J., dissenting

things, that the State’s intended use of midazolam would
violate the Eighth Amendment because, unlike sodium
thiopental or pentobarbital, the drug “is incapable of
producing a state of unawareness that will be reliably
maintained after either of the other two pain-producing
drugs . . . is injected.” Amended Complaint ¶101.
   The District Court held a 3-day evidentiary hearing, at
which petitioners relied principally on the testimony of
two experts: Dr. David Lubarsky, an anesthesiologist, and
Dr. Larry Sasich, a doctor of pharmacy. The State, in
turn, based its case on the testimony of Dr. Roswell Evans,
also a doctor of pharmacy.
   To a great extent, the experts’ testimony overlapped.
All three experts agreed that midazolam is from a class of
sedative drugs known as benzodiazepines (a class that
includes Valium and Xanax), and that it has no analge­
sic—or pain-relieving—effects. App. 205 (Lubarsky), 260–
261 (Sasich), 311 (Evans). They further agreed that while
midazolam can be used to render someone unconscious, it
is not approved by the Federal Drug Administration (FDA)
for use as, and is not in fact used as, a “sole drug to pro­
duce and maintain anesthesia in surgical proceedings.”
Id., at 307, 327 (Evans); see id., at 171 (Lubarsky); id., at
262 (Sasich). Finally, all three experts recognized that
midazolam is subject to a ceiling effect, which means that
there is a point at which increasing the dose of the drug
does not result in any greater effect.          Id., at 172
(Lubarsky), 243 (Sasich), 331 (Evans).
   The experts’ opinions diverged, however, on the crucial
questions of how this ceiling effect operates, and whether
it will prevent midazolam from keeping a condemned
inmate unconscious when the second and third lethal
injection drugs are administered. Dr. Lubarsky testified
that while benzodiazepines such as midazolam may, like
barbiturate drugs such as sodium thiopental and pento­
barbital, induce unconsciousness by inhibiting neuron
6                        GLOSSIP v. GROSS

                      SOTOMAYOR, J., dissenting

function, they do so in a materially different way. Id., at
207. More specifically, Dr. Lubarsky explained that both
barbiturates and benzodiazepines initially cause sedation
by facilitating the binding of a naturally occurring chemi­
cal called gamma-aminobutyric acid (GABA) with GABA
receptors, which then impedes the flow of electrical im­
pulses through the neurons in the central nervous system.
Id., at 206. But at higher doses, barbiturates also act as a
GABA substitute and mimic its neuron-suppressing ef­
fects. Ibid. By contrast, benzodiazepines lack this mim­
icking function, which means their effect is capped at a
lower level of sedation. Ibid. Critically, according to Dr.
Lubarsky, this ceiling on midazolam’s sedative effect is
reached before full anesthesia can be achieved. Ibid.
Thus, in his view, while “midazolam unconsciousness is
. . . sufficient” for “minor procedure[s],” Tr. of Preliminary
Injunction Hearing 132–133 (Tr.), it is incapable of keep­
ing someone “insensate and immobile in the face of [more]
noxious stimuli,” including the extreme pain and discom­
fort associated with administration of the second and third
drugs in Oklahoma’s lethal injection protocol, App. 218.
Dr. Sasich endorsed Dr. Lubarsky’s description of the
ceiling effect, and offered similar reasons for reaching the
same conclusion. See id., at 243, 248, 262.
    In support of these assertions, both experts cited a
variety of evidence. Dr. Lubarsky emphasized, in particu­
lar, Arizona’s 2014 execution of Joseph Wood, which had
been conducted using midazolam and the drug hydromor­
phone rather than the three-drug cocktail Oklahoma
intends to employ.1 Id., at 176. Despite being adminis­
tered 750 milligrams of midazolam, Wood had continued
breathing and moving for nearly two hours—which, ac­
——————
  1 Hydromorphone is a powerful analgesic similar to morphine or hero­

in. See R. Stoelting & S. Hillier, Pharmacology & Physiology in Anes­
thetic Practice 87–88 (4th ed. 2006) (Stoelting & Hillier).
                 Cite as: 576 U. S. ____ (2015)            7

                   SOTOMAYOR, J., dissenting

cording to Dr. Lubarsky, would not have occurred “during
extremely deep levels of anesthesia.” Id., at 177. Both
experts also cited various scientific articles and textbooks
to support their conclusions. For instance, Dr. Lubarsky
relied on a study measuring the brain activity of rats that
were administered midazolam, which showed that the
drug’s impact significantly tailed off at higher doses. See
Hovinga et al., Pharmacokinetic-EEG Effect Relationship
of Midazolam in Aging BN/BiRij Rats, 107 British J.
Pharmacology 171, 173, Fig. 2 (1992). He also pointed to a
pharmacology textbook that confirmed his description of
how benzodiazepines and barbiturates produce their
effects, see Stoelting & Hillier 127–128, 140–144, and a
survey article concluding that “[m]idazolam cannot be
used alone . . . to maintain adequate anesthesia,” Reves,
Fragen, Vinik, & Greenblatt, Midazolam: Pharmacology
and Uses, 62 Anesthesiology 310, 318 (1985) (Reves). For
his part, Dr. Sasich referred to a separate survey article,
which similarly recognized and described the ceiling effect
to which benzodiazepines are subject. See Saari, Uusi-
Oukari, Ahonen, & Olkkola, Enhancement of GABAergic
Activity: Neuropharmacological Effects of Benzodiazepines
and Therapeutic Use in Anesthesiology, 63 Pharamacolog­
ical Rev. 243, 244, 250 (2011) (Saari).
  By contrast, Dr. Evans, the State’s expert, asserted that
a 500-milligram dose of midazolam would “render the
person unconscious and ‘insensate’ during the remainder
of the [execution] procedure.” App. 294. He rested this
conclusion on two interrelated propositions.
  First, observing that a therapeutic dose of midazolam to
treat anxiety is less than 5 milligrams for a 70-kilogram
adult, Dr. Evans emphasized that Oklahoma’s planned
administration of 500 milligrams of the drug was “at least
100 times the normal therapeutic dose.” Ibid. While he
acknowledged that “[t]here are no studies that have been
done . . . administering that much . . . midazolam . . . to
8                    GLOSSIP v. GROSS

                   SOTOMAYOR, J., dissenting

anybody,” he noted that deaths had occurred in doses as
low as 0.04 to 0.07 milligrams per kilogram (2.8 to 4.9
milligrams for a 70-kilogram adult), and contended that a
500-milligram dose would itself cause death within less
than an hour—a conclusion he characterized as “essentially
an extrapolation from a toxic effect.” Id., at 327; see id.,
at 308.
   Second, in explaining how he reconciled his opinion with
the evidence of midazolam’s ceiling effect, Dr. Evans testi­
fied that while “GABA receptors are found across the
entire body,” midazolam’s ceiling effect is limited to the
“spinal cord” and there is “no ceiling effect” at the “higher
level of [the] brain.” Id., at 311–312. Consequently, in his
view, “as you increase the dose of midazolam, it’s a linear
effect, so you’re going to continue to get an impact from
higher doses of the drug,” id., at 332, until eventually
“you’re paralyzing the brain,” id., at 314. Dr. Evans also
understood the chemical source of midazolam’s ceiling
effect somewhat differently from petitioners’ experts.
Although he agreed that midazolam produces its effect by
“binding to [GABA] receptors,” id., at 293, he appeared to
believe that midazolam produced sedation by “inhibiting
GABA” from attaching to GABA receptors, not by promot­
ing GABA’s sedative effects, id., at 312. Thus, when asked
about Dr. Lubarsky’s description of the ceiling effect, Dr.
Evans characterized the phenomenon as stemming from
“the competitive nature of substances trying to attach to
GABA receptors.” Id., at 313.
   Dr. Evans cited no scholarly research in support of his
opinions. Instead, he appeared to rely primarily on two
sources: the Web site www.drugs.com, and a “Material
Safety Data Sheet” produced by a midazolam manufacturer.
See id., at 303. Both simply contained general infor­
mation that covered the experts’ areas of agreement.
                   Cite as: 576 U. S. ____ (2015)              9

                    SOTOMAYOR, J., dissenting

                             D
  The District Court denied petitioners’ motion for a
preliminary injunction. It began by making a series of
factual findings regarding the characteristics of midazo­
lam and its use in Oklahoma’s execution protocol. Most
relevant here, the District Court found that “[t]he proper
administration of 500 milligrams of midazolam . . . would
make it a virtual certainty that an individual will be at a
sufficient level of unconsciousness to resist the noxious
stimuli which could occur from the application of the
second and third drugs.” Id., at 77. Respecting petition­
ers’ contention that there is a “ceiling effect which pre­
vents an increase in dosage from having a corresponding
incremental effect on anesthetic depth,” the District Court
concluded:
    “Dr. Evans testified persuasively . . . that whatever
    the ceiling effect of midazolam may be with respect to
    anesthesia, which takes effect at the spinal cord level,
    there is no ceiling effect with respect to the ability of a
    500 milligram dose of midazolam to effectively para­
    lyze the brain, a phenomenon which is not anesthesia
    but does have the effect of shutting down respiration
    and eliminating the individual’s awareness of pain.”
    Id., at 78.
   Having made these findings, the District Court held
that petitioners had shown no likelihood of success on the
merits of their Eighth Amendment claim for two inde­
pendent reasons. First, it determined that petitioners had
“failed to establish that proceeding with [their] execu­
tion[s] . . . on the basis of the revised protocol presents . . .
‘an objectively intolerable risk of harm.’ ” Id., at 96. Sec­
ond, the District Court held that petitioners were unlikely
to prevail because they had not identified any “ ‘known and
available alternative’ ” means by which they could be
executed—a requirement it understood Baze to impose.
10                   GLOSSIP v. GROSS

                   SOTOMAYOR, J., dissenting

Id., at 97. The District Court concluded that the State
“ha[d] affirmatively shown that sodium thiopental and
pentobarbital, the only alternatives to which the [petition­
ers] have even alluded, are not available to the [State].”
Id., at 98.
   The Court of Appeals for the Tenth Circuit affirmed.
Warner v. Gross, 776 F. 3d 721 (2015). It, like the District
Court, held that petitioners were unlikely to prevail on the
merits because they had failed to prove the existence of
“ ‘known and available alternatives.’ ” Id., at 732. “In any
event,” the court continued, it was unable to conclude that
the District Court’s factual findings had been clearly
erroneous, and thus petitioners had also “failed to estab­
lish that the use of midazolam in their executions . . .
creates a demonstrated risk of severe pain.” Ibid.
   Petitioners and Charles Warner filed a petition for
certiorari and an application to stay their executions. The
Court denied the stay application, and Charles Warner
was executed on January 15, 2015. See Warner v. Gross,
574 U. S. ___ (2015) (SOTOMAYOR, J., dissenting from
denial of certiorari). The Court subsequently granted
certiorari and, at the request of the State, stayed petition­
ers’ pending executions.
                             II
  I begin with the second of the Court’s two holdings: that
the District Court properly found that petitioners did not
demonstrate a likelihood of showing that Oklahoma’s
execution protocol poses an unconstitutional risk of pain.
In reaching this conclusion, the Court sweeps aside sub­
stantial evidence showing that, while midazolam may be
able to induce unconsciousness, it cannot be utilized to
maintain unconsciousness in the face of agonizing stimuli.
Instead, like the District Court, the Court finds comfort in
Dr. Evans’ wholly unsupported claims that 500 milligrams
of midazolam will “paralyz[e] the brain.” In so holding,
                 Cite as: 576 U. S. ____ (2015)           11

                   SOTOMAYOR, J., dissenting

the Court disregards an objectively intolerable risk of
severe pain.
                              A
   Like the Court, I would review for clear error the Dis­
trict Court’s finding that 500 milligrams of midazolam will
render someone sufficiently unconscious “ ‘to resist the
noxious stimuli which could occur from the application of
the second and third drugs.’ ” Ante, at 18–19 (quoting App.
77). Unlike the Court, however, I would do so without
abdicating our duty to examine critically the factual predi­
cates for the District Court’s finding—namely, Dr. Evans’
testimony that midazolam has a “ceiling effect” only “at
the spinal cord level,” and that a “500 milligram dose of
midazolam” can therefore “effectively paralyze the brain.”
Id., at 78. To be sure, as the Court observes, such scien­
tific testimony may at times lie at the boundaries of fed­
eral courts’ expertise. See ante, at 17–18. But just because
a purported expert says something does not make it so.
Especially when important constitutional rights are at
stake, federal district courts must carefully evaluate the
premises and evidence on which scientific conclusions are
based, and appellate courts must ensure that the courts
below have in fact carefully considered all the evidence
presented. Clear error exists “when although there is
evidence to support” a finding, “the reviewing court on the
entire evidence is left with the definite and firm conviction
that a mistake has been committed.” United States v.
United States Gypsum Co., 333 U. S. 364, 395 (1948).
Here, given the numerous flaws in Dr. Evans’ testimony,
there can be little doubt that the District Court clearly
erred in relying on it.
   To begin, Dr. Evans identified no scientific literature to
support his opinion regarding midazolam’s properties at
higher-than-normal doses. Apart from a Material Safety
Data Sheet that was relevant only insofar as it suggests
12                   GLOSSIP v. GROSS

                   SOTOMAYOR, J., dissenting

that a low dose of midazolam may occasionally be toxic,
see ante, at 27—an issue I discuss further below—Dr.
Evans’ testimony seems to have been based on the Web
site www.drugs.com. The Court may be right that “peti­
tioners do not identify any incorrect statements from
drugs.com on which Dr. Evans relied.” Ante, at 27. But
that is because there were no statements from drugs.com
that supported the critically disputed aspects of Dr. Evans’
opinion. If anything, the Web site supported petitioners’
contentions, as it expressly cautioned that midazolam
“[s]hould not be used alone for maintenance of anesthe­
sia,” App. H to Pet. for Cert. 6159, and contained no warn­
ing that an excessive dose of midazolam could “paralyze
the brain,” see id., at 6528–6529.
   Most importantly, nothing from drugs.com—or, for that
matter, any other source in the record—corroborated Dr.
Evans’ key testimony that midazolam’s ceiling effect is
limited to the spinal cord and does not pertain to the
brain. Indeed, the State appears to have disavowed Dr.
Evans’ spinal-cord theory, refraining from even mention­
ing it in its brief despite the fact that the District Court
expressly relied on this testimony as the basis for finding
that larger doses of midazolam will have greater anesthetic
effects. App. 78. The Court likewise assiduously avoids
defending this theory.
   That is likely because this aspect of Dr. Evans’ testi-
mony was not just unsupported, but was directly refuted by
the studies and articles cited by Drs. Lubarsky and Sasich.
Both of these experts relied on academic texts describing
benzodiazepines’ ceiling effect and explaining why it pre­
vents these drugs from rendering a person completely
insensate. See Stoelting & Hillier 141, 144 (describing
midazolam’s ceiling effect and contrasting the drug with
barbiturates); Saari 244 (observing that “abolishment of
perception of environmental stimuli cannot usually be
generated”). One study further made clear that the ceiling
                     Cite as: 576 U. S. ____ (2015)                   13

                       SOTOMAYOR, J., dissenting

effect is apparent in the brain. See id., at 250.
  These scientific sources also appear to demonstrate that
Dr. Evans’ spinal-cord theory—i.e., that midazolam’s
ceiling effect is limited to the spinal cord—was premised
on a basic misunderstanding of midazolam’s mechanism of
action. I say “appear” not because the sources themselves
are unclear about how midazolam operates: They plainly
state that midazolam functions by promoting GABA’s
inhibitory effects on the central nervous system. See, e.g.,
Stoelting & Hillier 140. Instead, I use “appear” because
discerning the rationale underlying Dr. Evans’ testimony
is difficult. His spinal-cord theory might, however, be
explained at least in part by his apparent belief that rather
than promoting GABA’s inhibitory effects, midazolam
produces sedation by “compet[ing]” with GABA and thus
“inhibit[ing]” GABA’s effect. App. 312–313.2 Regardless, I
need not delve too deeply into Dr. Evans’ alternative
scientific reality. It suffices to say that to the extent that
Dr. Evans’ testimony was based on his understanding of
the source of midazolam’s pharmacological properties, that
understanding was wrong.
——————
  2 The Court disputes this characterization of Dr. Evans’ testimony,

insisting that Dr. Evans accurately described midazolam’s properties in
the written report he submitted prior to the hearing below, and sug­
gesting that petitioners’ experts would have “dispute[d] the accuracy” of
this explanation were it in fact wrong. Ante, at 25. But Dr. Evans’
written report simply said midazolam “produces different levels of
central nervous system (CNS) depression through binding to [GABA]
receptors.” App. 293. That much is true. Only after Drs. Sasich and
Lubarsky testified did Dr. Evans further claim that midazolam pro­
duced CNS depression by binding to GABA receptors and thereby
preventing GABA itself from binding to those receptors—which is where
he went wrong. The Court’s further observation that Dr. Lubarsky also
used a variant on the word “inhibiting” in his testimony—in saying that
GABA’s “ ‘inhibition of brain activity is accentuated by midazolam,’ ”
ante, at 25 (quoting App. 232)—is completely nonresponsive. “Inhibit­
ing” is a perfectly good word; the problem here is the manner in which
Dr. Evans used it in a sentence.
14                   GLOSSIP v. GROSS

                   SOTOMAYOR, J., dissenting

   These inconsistencies and inaccuracies go to the very
heart of Dr. Evans’ expert opinion, as they were the key
components of his professed belief that one can extrapolate
from what is known about midazolam’s effect at low doses
to conclude that the drug would “paralyz[e] the brain” at
Oklahoma’s planned dose. Id., at 314. All three experts
recognized that there had been no scientific testing on the
use of this amount of midazolam in conjunction with these
particular lethal injection drugs. See ante, at 19; App. 176
(Lubarsky), 243–244 (Sasich), 327 (Evans). For this rea­
son, as the Court correctly observes, “extrapolation was
reasonable.” Ante, at 20. But simply because extrapola­
tion may be reasonable or even required does not mean
that every conceivable method of extrapolation can be
credited, or that all estimates stemming from purported
extrapolation are worthy of belief. Dr. Evans’ view was
that because 40 milligrams of midazolam could be used to
induce unconsciousness, App. 294, and because more drug
will generally produce more effect, a significantly larger
dose of 500 milligrams would not just induce unconscious­
ness but allow for its maintenance in the face of extremely
painful stimuli, and ultimately even cause death itself. In
his words: “[A]s you increase the dose of midazolam, it’s a
linear effect, so you’re going to continue to get an impact
from higher doses of the drug.” Id., at 332. If, however,
there is a ceiling with respect to midazolam’s effect on the
brain—as petitioners’ experts established there is—then
such simplistic logic is not viable. In this context, more is
not necessarily better, and Dr. Evans was plainly wrong to
presume it would be.
   If Dr. Evans had any other basis for the “extrapolation”
that led him to conclude 500 milligrams of midazolam
would “paralyz[e] the brain,” id., at 314, it was even fur­
ther divorced from scientific evidence and logic. Having
emphasized that midazolam had been known to cause
approximately 80 deaths, Dr. Evans asserted that his
                     Cite as: 576 U. S. ____ (2015)                    15

                       SOTOMAYOR, J., dissenting

opinion regarding the efficacy of Oklahoma’s planned use
of the drug represented “essentially an extrapolation from
a toxic effect.” Id., at 327 (emphasis added); see id., at
308. Thus, Dr. Evans appeared to believe—and again, I
say “appeared” because his rationale is not clear—that
because midazolam caused some deaths, it would neces­
sarily cause complete unconsciousness and then death at
especially high doses. But Dr. Evans also thought, and
Dr. Lubarsky confirmed, that these midazolam fatalities
had occurred at very low doses—well below what any
expert said would produce unconsciousness. See id., at
207, 308. These deaths thus seem to represent the rare,
unfortunate side effects that one would expect to see with
any drug at normal therapeutic doses; they provide no
indication of the effect one would expect midazolam to
have on the brain at substantially higher doses. Deaths
occur with almost any product. One might as well say
that because some people occasionally die from eating one
peanut, one hundred peanuts would necessarily induce a
coma and death in anyone.3
  In sum, then, Dr. Evans’ conclusions were entirely
unsupported by any study or third-party source, contra­
dicted by the extrinsic evidence proffered by petitioners,
inconsistent with the scientific understanding of midazo­
lam’s properties, and apparently premised on basic logical
errors. Given these glaring flaws, the District Court’s
——————
  3 For all the reasons discussed in Part II–B, infra, and contrary to the
Court’s claim, see ante, at 20, n. 4, there are good reasons to doubt that
500 milligrams of midazolam will, in light of the ceiling effect, inevita­
bly kill someone. The closest the record comes to providing support for
this contention is the fleeting mention in the FDA-approved product
label that one of the possible consequences of midazolam overdosage is
coma. See ante, at 21, n. 5. Moreover, even if this amount of the drug
could kill some people in “under an hour,” ante, at 20, n. 4, that would
not necessarily mean that the condemned would be insensate during
the approximately 10 minutes it takes for the paralytic and potassium
chloride to do their work.
16                   GLOSSIP v. GROSS

                   SOTOMAYOR, J., dissenting

acceptance of Dr. Evans’ claim that 500 milligrams of
midazolam would “paralyz[e] the brain” cannot be credited.
This is not a case “[w]here there are two permissible
views of the evidence,” and the District Court chose one;
rather, it is one where the trial judge credited “one of two
or more witnesses” even though that witness failed to tell
“a coherent and facially plausible story that is not contra­
dicted by extrinsic evidence.” Anderson v. Bessemer City,
470 U. S. 564, 574–575 (1985). In other words, this is a
case in which the District Court clearly erred. See ibid.
                               B
   Setting aside the District Court’s erroneous factual
finding that 500 milligrams of midazolam will necessarily
“paralyze the brain,” the question is whether the Court is
nevertheless correct to hold that petitioners failed to
demonstrate that the use of midazolam poses an “objec­
tively intolerable risk” of severe pain. See Baze, 553 U. S.,
at 50 (plurality opinion) (internal quotation marks omit­
ted). I would hold that they made this showing. That is
because, in stark contrast to Dr. Evans, petitioners’ ex­
perts were able to point to objective evidence indicating
that midazolam cannot serve as an effective anesthetic
that “render[s] a person insensate to pain caused by the
second and third [lethal injection] drugs.” Ante, at 23.
   As observed above, these experts cited multiple sources
supporting the existence of midazolam’s ceiling effect.
That evidence alone provides ample reason to doubt mid­
azolam’s efficacy. Again, to prevail on their claim, peti­
tioners need only establish an intolerable risk of pain, not
a certainty. See Baze, 553 U. S., at 50. Here, the State is
attempting to use midazolam to produce an effect the drug
has never previously been demonstrated to produce, and
despite studies indicating that at some point increasing
the dose will not actually increase the drug’s effect. The
State is thus proceeding in the face of a very real risk that
                      Cite as: 576 U. S. ____ (2015)                    17

                       SOTOMAYOR, J., dissenting

the drug will not work in the manner it claims.
    Moreover, and perhaps more importantly, the record
provides good reason to think this risk is substantial. The
Court insists that petitioners failed to provide “probative
evidence” as to whether “midazolam’s ceiling effect occurs
below the level of a 500-milligram dose and at a point at
which the drug does not have the effect of rendering a
person insensate to pain.” Ante, at 23. It emphasizes that
Dr. Lubarsky was unable to say “at what dose the ceiling
effect occurs,” and could only estimate that it was
“ ‘[p]robably after about . . . 40 to 50 milligrams.’ ” Ante, at
23 (quoting App. 225).
    But the precise dose at which midazolam reaches its
ceiling effect is irrelevant if there is no dose at which the
drug can, in the Court’s words, render a person “insensate
to pain.” Ante, at 23. On this critical point, Dr. Lubarsky
was quite clear.4 He explained that the drug “does not
work to produce” a “lack of consciousness as noxious stim­
uli are applied,” and is “not sufficient to produce a surgical
plane of anesthesia in human beings.” App. 204. He also
——————
  4 Dr. Sasich, as the Court emphasizes, was perhaps more hesitant to
reach definitive conclusions, see ante, at 19–21, and n. 5, 23–24, but the
statements highlighted by the Court largely reflect his (truthful)
observations that no testing has been done at doses of 500 milligrams,
and his inability to pinpoint the precise dose at which midazolam's
ceiling effect might be reached. Dr. Sasich did not, as the Court sug­
gests, claim that midazolam’s ceiling effect would be reached only after
a person became fully insensate to pain. Ante, at 24. What Dr. Sasich
actually said was: “As the dose increases, the benzodiazepines are
expected to produce sedation, amnesia, and finally lack of response to
stimuli such as pain (unconsciousness).” App. 243. In context, it is
clear that Dr. Sasich was simply explaining that a drug like midazolam
can be used to induce unconsciousness—an issue that was and remains
undisputed—not that it could render an inmate sufficiently unconscious
to resist all noxious stimuli. Indeed, it was midazolam’s possible
inability to serve the latter function that led Dr. Sasich to conclude that
“it is not an appropriate drug to use when administering a paralytic
followed by potassium chloride.” Id., at 248.
18                       GLOSSIP v. GROSS

                      SOTOMAYOR, J., dissenting

noted that “[t]he drug would never be used and has never
been used as a sole anesthetic to give anesthesia during a
surgery,” id., at 223, and asserted that “the drug was not
approved by the FDA as a sole anesthetic because after
the use of fairly large doses that were sufficient to reach
the ceiling effect and produce induction of unconscious­
ness, the patients responded to the surgery,” id., at 219.
Thus, Dr. Lubarsky may not have been able to identify
whether this effect would be reached at 40, 50, or 60 milli­
grams or some higher threshold, but he could specify
that at no level would midazolam reliably keep an in-
mate unconscious once the second and third drugs were
delivered.5
   These assertions were amply supported by the evidence
of the manner in which midazolam is and can be used. All
three experts agreed that midazolam is utilized as the sole
sedative only in minor procedures. Dr. Evans, for exam­
ple, acknowledged that while midazolam may be used as
the sole drug in some procedures that are not “terribly
invasive,” even then “you would [generally] see it used in
combination with a narcotic.” Id., at 307. And though, as
the Court observes, Dr. Sasich believed midazolam could
be “used for medical procedures like colonoscopies and
gastroscopies,” ante, at 21, he insisted that these proce­
dures were not necessarily painful, and that it would be a
——————
  5 The Court claims that the District Court could have properly disre­

garded Dr. Lubarsky’s testimony because he asserted that a protocol
with sodium thiopental would “ ‘produce egregious harm and suffer­
ing.’ ” Ante, at 24, n. 6 (quoting App. 227). But Dr. Lubarsky did not
testify that, like midazolam, sodium thiopental would not render an
inmate fully insensate even if properly administered; rather, he simply
observed that he had previously contended that protocols using that
drug were ineffective. See App. 227. He was presumably referring to
an article he coauthored that found many condemned inmates were not
being successfully delivered the dose of sodium thiopental necessary to
fully anesthetize them. See Baze, 553 U. S., at 67 (ALITO, J., concur­
ring) (discussing this study).
                 Cite as: 576 U. S. ____ (2015)          19

                  SOTOMAYOR, J., dissenting

“big jump” to conclude that midazolam would be effective
to maintain unconsciousness throughout an execution. Tr.
369–370. Indeed, the record provides no reason to think
that these procedures cause excruciating pain remotely
comparable to that produced by the second and third
lethal injection drugs Oklahoma intends to use.
   As for more painful procedures, the consensus was also
clear: Midazolam is not FDA-approved for, and is not used
as, a sole drug to maintain unconsciousness. See App. 171
(Lubarsky), 262 (Sasich), 327 (Evans). One might infer
from the fact that midazolam is not used as the sole anes­
thetic for more serious procedures that it cannot be used
for them. But drawing such an inference is unnecessary,
as petitioners’ experts invoked sources expressly stating
as much. In particular, Dr. Lubarsky pointed to a survey
article that cited four separate authorities and declared
that “[m]idazolam cannot be used alone . . . to maintain
adequate anesthesia.” Reves 318; see also Stoelting &
Hillier 145 (explaining that midzolam is used for “induc­
tion of anesthesia,” and that, “[i]n combination with other
drugs, [it] may be used for maintenance of anesthesia”
(emphasis added)).
   This evidence was alone sufficient, but if one wanted
further support for these conclusions it was provided by
the Lockett and Wood executions. The procedural flaws
that marred the Lockett execution created the conditions
for an unintended (and grotesque) experiment on midazo­
lam’s efficacy. Due to problems with the IV line, Lockett
was not fully paralyzed after the second and third drugs
were administered. He had, however, been administered
more than enough midazolam to “render an average per­
son unconscious,” as the District Court found. App. 57.
When Lockett awoke and began to writhe and speak, he
demonstrated the critical difference between midazolam’s
ability to render an inmate unconscious and its ability to
maintain the inmate in that state. The Court insists that
20                       GLOSSIP v. GROSS

                      SOTOMAYOR, J., dissenting

Lockett’s execution involved “only 100 milligrams of mid­
azolam,” ante, at 28, but as explained previously, more is
not necessarily better given midazolam’s ceiling effect.
  The Wood execution is perhaps even more probative.
Despite being given over 750 milligrams of midazolam,
Wood gasped and snorted for nearly two hours. These
reactions were, according to Dr. Lubarsky, inconsistent
with Wood being fully anesthetized, App. 177–178, and
belie the claim that a lesser dose of 500 milligrams would
somehow suffice. The Court attempts to distinguish the
Wood execution on the ground that the timing of Arizona’s
administration of midazolam was different. Ante, at 28.
But as Dr. Lubarsky testified, it did not “matter” whether
in Wood’s execution the “midazolam was introduced all at
once or over . . . multiple doses,” because “[t]he drug has a
sufficient half life that the effect is cumulative.” App. 220;
see also Saari 253 (midazolam’s “elimination half-life
ranges from 1.7 to 3.5 h[ours]”).6 Nor does the fact that
Wood’s dose of midazolam was paired with hydromor­
phone rather than a paralytic and potassium chromide,
see ante, at 29, appear to have any relevance—other than
that the use of this analgesic drug may have meant that
Wood did not experience the same degree of searing pain
that an inmate executed under Oklahoma’s protocol may
face.
  By contrast, Florida’s use of this same three-drug proto­
col in 11 executions, see ante, at 28 (citing Brief for State
of Florida as Amicus Curiae 1), tells us virtually nothing.
Although these executions have featured no obvious mis­
haps, the key word is “obvious.” Because the protocol
——————
  6 The Court asserts that the State refuted these contentions, pointing

to Dr. Evans’ testimony that 750 milligrams of the drug “might not
have the effect that was sought” if administered over an hour. Tr. 667;
see ante, at 28, n. 6. But as has been the theme here, this pronounce­
ment was entirely unsupported, and appears to be contradicted by the
secondary sources cited by petitioners’ experts.
                    Cite as: 576 U. S. ____ (2015)                 21

                      SOTOMAYOR, J., dissenting

involves the administration of a powerful paralytic, it is,
as Drs. Sasich and Lubarsky explained, impossible to tell
whether the condemned inmate in fact remained uncon­
scious. App. 218, 273; see also Baze, 553 U. S., at 71
(Stevens, J., concurring in judgment). Even in these
executions, moreover, there have been indications of the
inmates’ possible awareness. See Brief for State of Ala­
bama et al. as Amici Curiae 9–13 (describing the 11 Flor-
ida executions, and noting that some allegedly involved
blinking and other movement after administration of the
three drugs).7
   Finally, none of the State’s “safeguards” for administer­
ing these drugs would seem to mitigate the substantial
risk that midazolam will not work, as the Court contends.
See ante, at 21–22. Protections ensuring that officials
have properly secured a viable IV site will not enable
midazolam to have an effect that it is chemically incapable
of having. Nor is there any indication that the State’s
monitoring of the inmate’s consciousness will be able to
anticipate whether the inmate will remain unconscious
while the second and third drugs are administered. No
one questions whether midazolam can induce uncon­
sciousness. The problem, as Lockett’s execution vividly
illustrates, is that an unconscious inmate may be awak­
ened by the pain and respiratory distress caused by ad­
ministration of the second and third drugs. At that point,
even if it were possible to determine whether the inmate is
conscious—dubious, given the use of a paralytic—it is
already too late. Presumably for these reasons, the Tenth
Circuit characterized the District Court’s reliance on these
procedural mechanisms as “not relevant to its rejection of
——————
  7 The fact that courts in Florida have approved the use of midazolam

in this fashion is arguably slightly more relevant, though it is worth
noting that the majority of these decisions were handed down before
the Lockett and Wood executions, and that some relied, as here, on Dr.
Evans’ testimony. See ante, at 17.
22                   GLOSSIP v. GROSS

                   SOTOMAYOR, J., dissenting

[petitioners’] claims regarding the inherent characteristics
of midazolam.” Warner, 776 F. 3d, at 733.
                             C
  The Court not only disregards this record evidence of
midazolam’s inadequacy, but also fails to fully appreciate
the procedural posture in which this case arises. Petition­
ers have not been accorded a full hearing on the merits of
their claim. They were granted only an abbreviated evi­
dentiary proceeding that began less than three months
after the State issued its amended execution protocol; they
did not even have the opportunity to present rebuttal
evidence after Dr. Evans testified. They sought a prelimi­
nary injunction, and thus were not required to prove their
claim, but only to show that they were likely to succeed on
the merits. See Winter v. Natural Resources Defense
Council, Inc., 555 U. S. 7, 20 (2008); Hill v. McDonough,
547 U. S. 573, 584 (2006).
  Perhaps the State could prevail after a full hearing,
though this would require more than Dr. Evans’ unsup­
ported testimony. At the preliminary injunction stage,
however, petitioners presented compelling evidence sug­
gesting that midazolam will not work as the State intends.
The State, by contrast, offered absolutely no contrary
evidence worth crediting. Petitioners are thus at the very
least likely to prove that, due to midazolam’s inherent
deficiencies, there is a constitutionally intolerable risk
that they will be awake, yet unable to move, while chemi­
cals known to cause “excruciating pain” course through
their veins. Baze, 553 U. S., at 71 (Stevens, J., concurring
in judgment).
                            III
  The Court’s determination that the use of midazolam
poses no objectively intolerable risk of severe pain is fac­
tually wrong. The Court’s conclusion that petitioners’
                 Cite as: 576 U. S. ____ (2015)           23

                   SOTOMAYOR, J., dissenting

challenge also fails because they identified no available
alternative means by which the State may kill them is
legally indefensible.
                               A
    This Court has long recognized that certain methods of
execution are categorically off-limits. The Court first
confronted an Eighth Amendment challenge to a method
of execution in Wilkerson v. Utah, 99 U. S. 130 (1879).
Although Wilkerson approved the particular method at
issue—the firing squad—it made clear that “public dissec­
tion,” “burning alive,” and other “punishments of torture
. . . in the same line of unnecessary cruelty, are forbidden
by [the Eighth A]mendment to the Constitution.” Id., at
135–136. Eleven years later, in rejecting a challenge to
the first proposed use of the electric chair, the Court again
reiterated that “if the punishment prescribed for an of­
fense against the laws of the State were manifestly cruel
and unusual, as burning at the stake, crucifixion, breaking
on the wheel, or the like, it would be the duty of the courts
to adjudge such penalties to be within the constitutional
prohibition.” In re Kemmler, 136 U. S. 436, 446 (1890).
    In the more than a century since, the Members of this
Court have often had cause to debate the full scope of the
Eighth Amendment’s prohibition of cruel and unusual
punishment. See, e.g., Furman v. Georgia, 408 U. S. 238
(1972). But there has been little dispute that it at the
very least precludes the imposition of “barbarous physical
punishments.” Rhodes v. Chapman, 452 U. S. 337, 345
(1981); see, e.g., Solem v. Helm, 463 U. S. 277, 284 (1983);
id., at 312–313 (Burger, C. J., dissenting); Baze, 553 U. S.,
at 97–99 (THOMAS, J., concurring in judgment); Harmelin
v. Michigan, 501 U. S. 957, 976 (1991) (opinion of SCALIA,
J.). Nor has there been any question that the Amendment
prohibits such “inherently barbaric punishments under all
circumstances.” Graham v. Florida, 560 U. S. 48, 59
24                   GLOSSIP v. GROSS

                   SOTOMAYOR, J., dissenting

(2010) (emphasis added). Simply stated, the “Eighth
Amendment categorically prohibits the infliction of cruel
and unusual punishments.” Penry v. Lynaugh, 492 U. S.
302, 330 (1989) (emphasis added).
                               B
   The Court today, however, would convert this categori­
cal prohibition into a conditional one. A method of execu­
tion that is intolerably painful—even to the point of being
the chemical equivalent of burning alive—will, the Court
holds, be unconstitutional if, and only if, there is a “known
and available alternative” method of execution. Ante, at
15. It deems Baze to foreclose any argument to the con­
trary. Ante, at 14.
   Baze held no such thing. In the first place, the Court
cites only the plurality opinion in Baze as support for its
known-and-available-alternative requirement. See ibid.
Even assuming that the Baze plurality set forth such a
requirement—which it did not—none of the Members of
the Court whose concurrences were necessary to sustain
the Baze Court’s judgment articulated a similar view. See
553 U. S., at 71–77, 87 (Stevens, J., concurring in judg­
ment); id., at 94, 99–107 (THOMAS, J., concurring in judg­
ment); id., at 107–108, 113 (BREYER, J., concurring in
judgment). In general, “the holding of the Court may be
viewed as that position taken by those Members who
concurred in the judgments on the narrowest grounds.”
Marks v. United States, 430 U. S. 188, 193 (1977) (internal
quotation marks omitted). And as the Court observes,
ante, at 14, n. 2, the opinion of JUSTICE THOMAS, joined by
JUSTICE SCALIA, took the broadest position with respect to
the degree of intent that state officials must have in
order to have violated the Eighth Amendment, concluding
that only a method of execution deliberately designed
to inflict pain, and not one simply designed with deliberate
indifference to the risk of severe pain, would be un­
                 Cite as: 576 U. S. ____ (2015)           25

                   SOTOMAYOR, J., dissenting

constitutional. 553 U. S., at 94 (THOMAS, J., concurring
in judgment). But this understanding of the Eighth
Amendment’s intent requirement is unrelated to, and thus
not any broader or narrower than, the requirement the
Court now divines from Baze. Because the position that a
plaintiff challenging a method of execution under the
Eighth Amendment must prove the availability of an
alternative means of execution did not “represent the
views of a majority of the Court,” it was not the holding of
the Baze Court. CTS Corp. v. Dynamics Corp. of America,
481 U. S. 69, 81 (1987).
   In any event, even the Baze plurality opinion provides
no support for the Court’s proposition. To be sure, that
opinion contains the following sentence: “[The condemned]
must show that the risk is substantial when compared to
the known and available alternatives.” 553 U. S., at 61.
But the meaning of that key sentence and the limits of the
requirement it imposed are made clear by the sentence
directly preceding it: “A stay of execution may not be
granted on grounds such as those asserted here unless the
condemned prisoner establishes that the State’s lethal
injection protocol creates a demonstrated risk of severe
pain.” Ibid. (emphasis added). In Baze, the very premise
of the petitioners’ Eighth Amendment claim was that they
had “identified a significant risk of harm [in Kentucky’s
protocol] that [could] be eliminated by adopting alterna­
tive procedures.” Id., at 51. Their basic theory was that
even if the risk of pain was only, say, 25%, that risk would
be objectively intolerable if there was an obvious alterna­
tive that would reduce the risk to 5%. See Brief for Peti­
tioners in Baze v. Rees, O. T. 2007, No. 07–5439, p. 29 (“In
view of the severity of the pain risked and the ease with
which it could be avoided, Petitioners should not have
been required to show a high likelihood that they would
suffer such pain . . . ”). Thus, the “grounds . . . asserted”
for relief in Baze were that the State’s protocol was intol­
26                   GLOSSIP v. GROSS

                   SOTOMAYOR, J., dissenting

erably risky given the alternative procedures the State
could have employed.
   Addressing this claim, the Baze plurality clarified that
“a condemned prisoner cannot successfully challenge a
State’s method of execution merely by showing a slightly
or marginally safer alternative,” 553 U. S., at 51; instead,
to succeed in a challenge of this type, the comparative risk
must be “substantial,” id., at 61. Nowhere did the plurality
suggest that all challenges to a State’s method of execu­
tion would require this sort of comparative-risk analysis.
Recognizing the relevance of available alternatives is not
at all the same as concluding that their absence precludes
a claimant from showing that a chosen method carries
objectively intolerable risks. If, for example, prison offi­
cials chose a method of execution that has a 99% chance of
causing lingering and excruciating pain, certainly that
risk would be objectively intolerable whether or not the
officials ignored other methods in making this choice.
Irrespective of the existence of alternatives, there are
some risks “so grave that it violates contemporary stand­
ards of decency to expose anyone unwillingly to” them.
Helling v. McKinney, 509 U. S. 25, 36 (1993) (emphasis in
original).
   That the Baze plurality’s statement regarding a con­
demned inmate’s ability to point to an available alterna­
tive means of execution pertained only to challenges prem­
ised on the existence of such alternatives is further
evidenced by the opinion’s failure to distinguish or even
mention the Court’s unanimous decision in Hill v.
McDonough, 547 U. S. 573. Hill held that a §1983 plain­
tiff challenging a State’s method of execution need not
“identif[y] an alternative, authorized method of execution.”
Id., at 582. True, as the Court notes, ante, at 14–15, Hill
did so in the context of addressing §1983’s pleading stand­
ard, rejecting the proposed alternative-means requirement
because the Court saw no basis for the “[i]mposition of
                 Cite as: 576 U. S. ____ (2015)          27

                   SOTOMAYOR, J., dissenting

heightened pleading requirements.” 547 U. S., at 582.
But that only confirms that the Court in Hill did not view
the availability of an alternative means of execution as an
element of an Eighth Amendment claim: If it had, then
requiring the plaintiff to plead this element would not
have meant imposing a heightened standard at all, but
rather would have been entirely consistent with “tradi­
tional pleading requirements.” Ibid.; see Ashcroft v. Iqbal,
556 U. S. 662, 678 (2009). The Baze plurality opinion
should not be understood to have so carelessly tossed aside
Hill’s underlying premise less than two years later.
                              C
   In reengineering Baze to support its newfound rule, the
Court appears to rely on a flawed syllogism. If the death
penalty is constitutional, the Court reasons, then there
must be a means of accomplishing it, and thus some avail­
able method of execution must be constitutional. See ante,
at 4, 15–16. But even accepting that the death penalty is,
in the abstract, consistent with evolving standards of
decency, but see ante, p. ___ (BREYER, J., dissenting), the
Court’s conclusion does not follow. The constitutionality of
the death penalty may inform our conception of the degree
of pain that would render a particular method of imposing
it unconstitutional. See Baze, 553 U. S., at 47 (plurality
opinion) (because “[s]ome risk of pain is inherent in any
method of execution,” “[i]t is clear . . . the Constitution
does not demand the avoidance of all risk of pain”). But a
method of execution that is “barbarous,” Rhodes, 452
U. S., at 345, or “involve[s] torture or a lingering death,”
Kemmler, 136 U. S., at 447, does not become less so just
because it is the only method currently available to a
State. If all available means of conducting an execution
constitute cruel and unusual punishment, then conducting
the execution will constitute cruel and usual punishment.
Nothing compels a State to perform an execution. It does
28                        GLOSSIP v. GROSS

                       SOTOMAYOR, J., dissenting

not get a constitutional free pass simply because it desires
to deliver the ultimate penalty; its ends do not justify any
and all means. If a State wishes to carry out an execution,
it must do so subject to the constraints that our Constitu­
tion imposes on it, including the obligation to ensure that
its chosen method is not cruel and unusual. Certainly the
condemned has no duty to devise or pick a constitutional
instrument of his or her own death.
   For these reasons, the Court’s available-alternative
requirement leads to patently absurd consequences.
Petitioners contend that Oklahoma’s current protocol is a
barbarous method of punishment—the chemical equiva­
lent of being burned alive. But under the Court’s new
rule, it would not matter whether the State intended to
use midazolam, or instead to have petitioners drawn and
quartered, slowly tortured to death, or actually burned at
the stake: because petitioners failed to prove the availabil­
ity of sodium thiopental or pentobarbital, the State could
execute them using whatever means it designated. But
see Baze, 553 U. S., at 101–102 (THOMAS, J., concurring in
judgment) (“It strains credulity to suggest that the defin­
ing characteristic of burning at the stake, disemboweling,
drawing and quartering, beheading, and the like was that
they involved risks of pain that could be eliminated by
using alternative methods of execution”).8 The Eighth
Amendment cannot possibly countenance such a result.
                            D
 In concocting this additional requirement, the Court is
motivated by a desire to preserve States’ ability to conduct
——————
   8 The Court protests that its holding does not extend so far, deriding

this description of the logical implications of its legal rule as “simply
not true” and “outlandish rhetoric.” Ante, at 29. But presumably when
the Court imposes a “requirement o[n] all Eighth Amendment method-
of-execution claims,” that requirement in fact applies to “all” methods
of execution, without exception. Ante, at 1 (emphasis added).
                 Cite as: 576 U. S. ____ (2015)           29

                   SOTOMAYOR, J., dissenting

executions in the face of changing circumstances. See
ante, at 4–6, 27–28. It is true, as the Court details, that
States have faced “practical obstacle[s]” to obtaining lethal
injection drugs since Baze was decided. Ante, at 4. One
study concluded that recent years have seen States change
their protocols “with a frequency that is unprecedented
among execution methods in this country’s history.” Denno,
Lethal Injection Chaos Post-Baze, 102 Geo. L. J. 1331,
1335 (2014).
   But why such developments compel the Court’s imposi­
tion of further burdens on those facing execution is a
mystery. Petitioners here had no part in creating the
shortage of execution drugs; it is odd to punish them for
the actions of pharmaceutical companies and others who
seek to disassociate themselves from the death penalty—
actions which are, of course, wholly lawful. Nor, certainly,
should these rapidly changing circumstances give us any
greater confidence that the execution methods ultimately
selected will be sufficiently humane to satisfy the Eighth
Amendment. Quite the contrary. The execution protocols
States hurriedly devise as they scramble to locate new and
untested drugs, see supra, at 3, are all the more likely to
be cruel and unusual—presumably, these drugs would
have been the States’ first choice were they in fact more
effective. But see Denno, The Lethal Injection Quandry:
How Medicine Has Dismantled the Death Penalty, 76
Ford. L. Rev. 49, 65–79 (2007) (describing the hurried and
unreasoned process by which States first adopted the
original three-drug protocol). Courts’ review of execution
methods should be more, not less, searching when States
are engaged in what is in effect human experimentation.
   It is also worth noting that some condemned inmates
may read the Court’s surreal requirement that they iden­
tify the means of their death as an invitation to propose
methods of executions less consistent with modern sensi­
bilities. Petitioners here failed to meet the Court’s new
30                   GLOSSIP v. GROSS

                   SOTOMAYOR, J., dissenting

test because of their assumption that the alternative
drugs to which they pointed, pentobarbital and sodium
thiopental, were available to the State. See ante, at 13–
14. This was perhaps a reasonable assumption, especially
given that neighboring Texas and Missouri still to this day
continue to use pentobarbital in executions. See The
Death Penalty Institute, Execution List 2015, online at
www.deathpenaltyinfo.org/execution-list-2015 (as visited
June 26, 2015, and available in the Clerk of the Court’s
case file).
   In the future, however, condemned inmates might well
decline to accept States’ current reliance on lethal injec­
tion. In particular, some inmates may suggest the firing
squad as an alternative. Since the 1920’s, only Utah has
utilized this method of execution. See S. Banner, The
Death Penalty 203 (2002); Johnson, Double Murderer
Executed by Firing Squad in Utah, N. Y. Times, June 19,
2010, p. A12. But there is evidence to suggest that the
firing squad is significantly more reliable than other
methods, including lethal injection using the various
combinations of drugs thus far developed. See A. Sarat,
Gruesome Spectacles: Botched Executions and America’s
Death Penalty, App. A, p. 177 (2014) (calculating that
while 7.12% of the 1,054 executions by lethal injection
between 1900 and 2010 were “botched,” none of the 34
executions by firing squad had been). Just as important,
there is some reason to think that it is relatively quick and
painless. See Banner, supra, at 203.
   Certainly, use of the firing squad could be seen as a
devolution to a more primitive era. See Wood v. Ryan, 759
F. 3d 1076, 1103 (CA9 2014) (Kozinski, C. J., dissenting
from denial of rehearing en banc). That is not to say, of
course, that it would therefore be unconstitutional. But
lethal injection represents just the latest iteration of the
States’ centuries-long search for “neat and non-disfiguring
homicidal methods.” C. Brandon, The Electric Chair: An
                 Cite as: 576 U. S. ____ (2015)           31

                   SOTOMAYOR, J., dissenting

Unnatural American History 39 (1999) (quoting Editorial,
New York Herald, Aug. 10, 1884); see generally Banner,
supra, at 169–207. A return to the firing squad—and the
blood and physical violence that comes with it—is a step in
the opposite direction. And some might argue that the
visible brutality of such a death could conceivably give rise
to its own Eighth Amendment concerns. See Campbell v.
Wood, 511 U. S. 1119, 1121–1123 (1994) (Blackmun, J.,
dissenting from denial of stay of execution and certiorari);
Glass v. Louisiana, 471 U. S. 1080, 1085 (1985) (Brennan,
J., dissenting from denial of certiorari). At least from a
condemned inmate’s perspective, however, such visible yet
relatively painless violence may be vastly preferable to an
excruciatingly painful death hidden behind a veneer of
medication. The States may well be reluctant to pull back
the curtain for fear of how the rest of us might react to
what we see. But we deserve to know the price of our
collective comfort before we blindly allow a State to make
condemned inmates pay it in our names.
                         *    *     *
   “By protecting even those convicted of heinous crimes,
the Eighth Amendment reaffirms the duty of the govern­
ment to respect the dignity of all persons.” Roper v. Sim-
mons, 543 U. S. 551, 560 (2005). Today, however, the
Court absolves the State of Oklahoma of this duty. It does
so by misconstruing and ignoring the record evidence
regarding the constitutional insufficiency of midazolam as
a sedative in a three-drug lethal injection cocktail, and by
imposing a wholly unprecedented obligation on the con­
demned inmate to identify an available means for his or
her own execution. The contortions necessary to save this
particular lethal injection protocol are not worth the price.
I dissent.
