                 Cite as: 583 U. S. ____ (2018)           1

                        Per Curiam
                   Statement of BREYER, J.

SUPREME COURT OF THE UNITED STATES
         ABEL DANIEL HIDALGO v. ARIZONA
  ON PETITION FOR WRIT OF CERTIORARI TO THE SUPREME 

                  COURT OF ARIZONA

             No. 17–251.   Decided March 19, 2018


  The petition for a writ of certiorari is denied.
  Statement of JUSTICE BREYER, with whom JUSTICE
GINSBURG, JUSTICE SOTOMAYOR, and JUSTICE KAGAN join,
respecting the denial of certiorari.
  The petition in this capital case asks an important
Eighth Amendment question:
    “Whether Arizona’s capital sentencing scheme, which
    includes so many aggravating circumstances that vir-
    tually every defendant convicted of first-degree mur-
    der is eligible for death, violates the Eighth Amend-
    ment.” Pet. for Cert. (i).
                             I
  “Our capital punishment cases under the Eighth
Amendment address two different aspects of the capital
decisionmaking process: the eligibility decision and the
selection decision.” Tuilaepa v. California, 512 U. S. 967,
971 (1994). States must comply with requirements for
each decision. See Kansas v. Marsh, 548 U. S. 163, 173–
174 (2006) (“Together, our decisions in Furman v. Georgia,
408 U. S. 238 (1972) (per curiam), and Gregg v. Georgia,
428 U. S. 153 (1976) (joint opinion of Stewart, Powell,
and Stevens, JJ.), establish that a state capital sentenc-
ing scheme must” comport with requirements for each
decision).
  In respect to the first, the “eligibility decision,” our
precedent imposes what is commonly known as the “nar-
rowing” requirement. “To pass constitutional muster, a
2                   HIDALGO v. ARIZONA

                    Statement of BREYER, J.

capital sentencing scheme must ‘genuinely narrow the
class of persons eligible for the death penalty and must
reasonably justify the imposition of a more severe sen-
tence on the defendant compared to others found guilty of
murder.’ ” Lowenfield v. Phelps, 484 U. S. 231, 244 (1988)
(quoting Zant v. Stephens, 462 U. S. 862, 877 (1983)). To
satisfy the “narrowing requirement,” a state legislature
must adopt “statutory factors which determine death
eligibility” and thereby “limit the class of murderers to
which the death penalty may be applied.” Brown v. Sand-
ers, 546 U. S. 212, 216, and n. 2 (2006) (emphasis added);
see also Tuilaepa, supra, at 979 (“ ‘Once the jury finds that
the defendant falls within the legislatively defined category
of persons eligible for the death penalty, . . . the jury then
is free to consider a myriad of factors to determine whether
death is the appropriate punishment’ ” (quoting Califor-
nia v. Ramos, 463 U. S. 992, 1008 (1983); emphasis
added)); Lowenfield, supra, at 246 (specifying that the
“legislature” may provide for the “narrowing function”
by statute (emphasis added)); Zant, supra, at 878
(“[S]tatutory aggravating circumstances play a constitu-
tionally necessary function at the stage of legislative defi-
nition: they circumscribe the class of persons eligible for
the death penalty” (emphasis added)).
   The second aspect of the capital decisionmaking process,
the “selection decision,” determines whether a death-
eligible defendant should actually receive the death penalty.
Tuilaepa, supra, at 972. In making this individualized
determination, the jury must “consider relevant mitigating
evidence of the character and record of the defendant and
the circumstances of the crime.” Ibid.; see also Marsh,
supra, at 173–174 (“[A] state capital sentencing system
must . . . permit a jury to render a reasoned, individual-
ized sentencing determination based on a death-eligible
defendant’s record, personal characteristics, and the cir-
cumstances of his crime”). This second aspect of the capi-
                   Cite as: 583 U. S. ____ (2018)               3

                     Statement of BREYER, J.

tal punishment decision—the selection requirement—is
not before us.
                             II
    Our precedent makes clear that the legislature may
satisfy the “narrowing function . . . in either of . . . two
ways.” Lowenfield, 484 U. S., at 246. First, “[t]he legisla-
ture may itself narrow the definition of capital offenses . . . .”
Ibid. (emphasis added). Second, “the legislature may more
broadly define capital offenses,” but set forth by statute
“aggravating circumstances” which will permit the “jury
. . . at the penalty phase” to make “findings” that will
narrow the legislature’s broad definition of the capital
offense. Ibid.; see also Tuilaepa, supra, at 972 (“The
aggravating circumstance may be contained in the defini-
tion of the crime or in a separate sentencing factor (or in
both)”). The petitioner here, Abel Daniel Hidalgo, con-
tends that the Arizona Legislature has failed to satisfy
the narrowing requirement through either of these two
methods.
                                 A
    Consider the first way a state legislature may satisfy
the Constitution’s narrowing requirement—namely, by
enacting a narrow statutory definition of capital murder.
Some States have followed this approach. For example, in
Lowenfield, this Court upheld Louisiana’s use of this
method because it concluded that the State’s capital mur-
der statute narrowed the class of intentional murderers to
a smaller class of death-eligible murderers. 484 U. S., at
246. Specifically, Louisiana’s capital murder statute was
limited to cases in which “ ‘the offender’ ” not only had
“ ‘specific intent to kill or to inflict great bodily harm’ ” but
also (1) targeted one of three specifically enumerated
categories of victims (children, “ ‘a fireman or peace officer
engaged’ ” in “ ‘lawful duties,’ ” or multiple victims); or (2)
4                    HIDALGO v. ARIZONA

                     Statement of BREYER, J.

was “ ‘engaged in the perpetration or attempted perpetra-
tion of ’ ” certain other serious specified crimes; or (3) was a
murder-for-hire. Id., at 242 (quoting La. Rev. Stat. Ann.
§§14:30(A)(1)–(5) (West 1986)). The Lowenfield Court also
noted that Texas’ capital murder statute “narrowly de-
fined the categories of murder for which a death sentence
could be imposed.” 484 U. S., at 245; see also Jurek v.
Texas, 428 U. S. 262, 271 (1976) (joint opinion of Stewart,
Powell, and Stevens, JJ.) (upholding the Texas capital
murder statute, which made “a smaller class of murders in
Texas” death eligible).
   Unlike the Louisiana and Texas statutes, Arizona’s
capital murder statute makes all first-degree murderers
eligible for death and defines first-degree murder broadly
to include all premeditated homicides along with felony
murder based on 22 possible predicate felony offenses. See
Ariz. Rev. Stat. Ann. §§13–1105(A)(1)–(2) (2010) (includ-
ing, for example, transporting marijuana for sale). Per-
haps not surprisingly, Arizona did not argue below and
does not suggest now that the State’s first-degree murder
statute alone can meet the Eighth Amendment’s narrow-
ing requirement.
                              B
  Because Arizona law broadly defines capital murder, the
State has sought to comply with the narrowing require-
ment through the second method—namely, by setting
forth statutory “aggravating circumstances” designed to
permit the “jury . . . at the penalty phase” to make “find-
ings” that will narrow the legislature’s broad definition of
the capital offense. Lowenfield, supra, at 246. The Arizona
Legislature has set forth a list of statutory aggravating
factors that the jury must consider “in determining
whether to impose a sentence of death.” Ariz. Rev. Stat.
Ann. §13–751(F) (Cum. Supp. 2017); see Appendix, infra.
And under Arizona law, a person convicted of first-degree
                 Cite as: 583 U. S. ____ (2018)           5

                   Statement of BREYER, J.

murder may be sentenced to death only if at least one of
these aggravating factors is present. §13–752(E).
   In this case, the petitioner sought an evidentiary hear-
ing to establish through witnesses, expert testimony, and
documentary evidence that the statutory aggravating
circumstances set forth in §13–751(F) apply to virtually
every first-degree murder case in the State. The state
trial court consolidated the petitioner’s motion for an
evidentiary hearing with similar motions filed by 17 other
first-degree murder defendants. See Brief in Opposition 4.
Unlike the petitioner, the other defendants had committed
their crimes after the Arizona Legislature increased the
number of statutory aggravating factors from 10 to 14.
Compare Ariz. Rev. Stat. Ann. §13–703(F) (2001) (10
aggravators) with Appendix, infra (14 aggravators).
   In his request for a hearing, the petitioner pointed to,
among other things, evidence he obtained through public
records requests regarding more than 860 first-degree
murder cases in Maricopa County (the county where he
was charged) between 2002 and 2012. As the Arizona
Supreme Court noted, this evidence indicated that “one or
more aggravating circumstances were present in 856 of
866” cases examined. 241 Ariz. 543, 550, 390 P. 3d 783,
789 (2017). In other words, about 98% of first-degree
murder defendants were eligible for the death penalty.
The petitioner adds in his briefing before this Court that
this is true under either the 10 aggravating factors in
effect when he was sentenced or the 14 factors set forth
under the expanded provisions Arizona has since adopted.
See Reply Brief 5 (citing C. Spohn, Aggravating Circum-
stances in First-Degree Murder Cases, Maricopa County,
AZ: 2002–2012).       Narrowing an impermissibly broad
capital murder statute by about 2% is not, the petitioner
says, sufficient under this Court’s precedents.
   The state trial court denied the petitioner’s request for
an evidentiary hearing, and the Arizona Supreme Court
6                   HIDALGO v. ARIZONA

                    Statement of BREYER, J.

affirmed. 241 Ariz., at 548–549, 390 P. 3d, at 788–789.
However, the Arizona Supreme Court did not dispute the
petitioner’s evidence. It assumed that “Hidalgo is right in
his factual assertion that nearly every charged first degree
murder could support at least one aggravating circum-
stance.” Id., at 551, 390 P. 3d, at 791.
                             C
   Despite assuming that the aggravating circumstances
fail to materially narrow the class of death-eligible first-
degree murder defendants, the Arizona Supreme Court
nevertheless concluded that the State’s death penalty
system meets the Constitution’s narrowing requirement.
It said that the petitioner was “mistaken . . . insofar as he
focuses only on the legislatively defined aggravating cir-
cumstances” because use of those circumstances “is not the
only way in which Arizona’s sentencing scheme narrows
the class of persons eligible for death.” Id., at 551–552,
390 P. 3d, at 791–792. The Arizona Supreme Court men-
tioned five other ways it thought Arizona’s death penalty
system meets the Constitution’s narrowing requirement.
They were: (1) Arizona’s first-degree murder statute; (2)
the “identified aggravating circumstances”; (3) the fact
that the State must prove “one or more” of the “alleged
aggravating circumstances” “beyond a reasonable doubt”;
(4) the existence of “mandatory appellate review”; and (5)
Arizona’s statutory provisions applicable to “individual-
ized sentencing determinations” through consideration of
“mitigating circumstances.” Id., at 552, 390 P. 3d, at 792.
   We have considered (and rejected) the first of these
other ways since Arizona’s first-degree murder statute
does not “provid[e] for categorical narrowing at the defini-
tion stage.” Zant, 462 U. S., at 879. What about the
second way—that is, narrowing by means of the “statutory
aggravators”? Again, the Arizona Supreme Court as-
sumed that those factors do not, in fact, narrow the class
                  Cite as: 583 U. S. ____ (2018)            7

                    Statement of BREYER, J.

of death-eligible first-degree murder defendants. Instead
it assumed that “Hidalgo is right in his factual assertion
that nearly every charged first degree murder could sup-
port at least one aggravating circumstance.” 241 Ariz., at
551, 390 P. 3d, at 791. That assumption, without more,
would seem to deny the constitutional need to “genuinely”
narrow the class of death-eligible defendants. Zant, su-
pra, at 877. Moreover, the third and fourth narrowing
methods the Arizona Supreme Court invoked are basically
beside the point—they do not show the necessary legisla-
tive narrowing that our precedents require. And the final
other way (individualized sentencing determinations)
concerns an entirely different capital punishment re-
quirement—the selection decision—which is not at issue in
this case. See supra, at 2–3.
   Finally, the Arizona Supreme Court seemed to suggest
that prosecutors may perform the narrowing requirement
by choosing to ask for the death penalty only in those
cases in which a particularly wrongful first-degree murder
is at issue. See 241 Ariz., at 551–552, 390 P. 3d, at 791–
792. However, that reasoning cannot be squared with this
Court’s precedent—precedent that insists that States
perform the “constitutionally necessary” narrowing func-
tion “at the stage of legislative definition.” Zant, supra, at
878 (emphasis added); see also Tuilaepa, 512 U. S., at 979;
Lowenfield, 484 U. S., at 246; Ramos, 463 U. S., at 1008.
                        *     *    *
   Although, in my view, the Arizona Supreme Court mis-
applied our precedent, I agree with the Court’s decision
today to deny certiorari.       In support of his Eighth
Amendment challenge, the petitioner points to empirical
evidence about Arizona’s capital sentence system that
suggests about 98% of first-degree murder defendants in
Arizona were eligible for the death penalty. That evidence
is unrebutted. It points to a possible constitutional prob-
8                   HIDALGO v. ARIZONA

                   Statement of BREYER, J.

lem. And it was assumed to be true by the state courts
below. Evidence of this kind warrants careful attention
and evaluation. However, in this case, the opportunity to
develop the record through an evidentiary hearing was
denied. As a result, the record as it has come to us is
limited and largely unexamined by experts and the courts
below in the first instance. We do not have evidence, for
instance, as to the nature of the 866 cases (perhaps they
implicate only a small number of aggravating factors).
Nor has it been fully explained whether and to what ex-
tent an empirical study would be relevant to resolving the
constitutional question presented. Capital defendants
may have the opportunity to fully develop a record with
the kind of empirical evidence that the petitioner points to
here. And the issue presented in this petition will be
better suited for certiorari with such a record.
                 Cite as: 583 U. S. ____ (2018)            9

                   Statement
               Appendix       of BREYER
                        to opinion      , J. , J.
                                   of BREYER

                       APPENDIX
   Ariz. Rev. Stat. Ann. §13–751(F) (Cum. Supp. 2017)

   “F. The trier of fact shall consider the following aggra-
vating circumstances in determining whether to impose a
sentence of death:
   “1. The defendant has been convicted of another offense
in the United States for which under Arizona law a sen-
tence of life imprisonment or death was imposable.
   “2. The defendant has been or was previously convicted
of a serious offense, whether preparatory or completed.
Convictions for serious offenses committed on the same
occasion as the homicide, or not committed on the same
occasion but consolidated for trial with the homicide, shall
be treated as a serious offense under this paragraph.
   “3. In the commission of the offense the defendant
knowingly created a grave risk of death to another person
or persons in addition to the person murdered during the
commission of the offense.
   “4. The defendant procured the commission of the of-
fense by payment, or promise of payment, of anything of
pecuniary value.
   “5. The defendant committed the offense as considera-
tion for the receipt, or in expectation of the receipt, of
anything of pecuniary value.
   “6. The defendant committed the offense in an especially
heinous, cruel or depraved manner.
   “7. The defendant committed the offense while:
   “(a) In the custody of or on authorized or unauthorized
release from the state department of corrections, a law
enforcement agency or a county or city jail.
   “(b) On probation for a felony offense.
   “8. The defendant has been convicted of one or more
other homicides . . . that were committed during the com-
mission of the offense.
   “9. The defendant was an adult at the time the offense
10                 HIDALGO v. ARIZONA

                   Statement
               Appendix       of BREYER
                        to opinion      , J. , J.
                                   of BREYER

was committed or was tried as an adult and the murdered
person was under fifteen years of age, was an unborn child
in the womb at any stage of its development or was seventy
years of age or older.
  “10. The murdered person was an on duty peace officer
who was killed in the course of performing the officer’s
official duties and the defendant knew, or should have
known, that the murdered person was a peace officer.
  “11. The defendant committed the offense with the
intent to promote, further or assist the objectives of a
criminal street gang or criminal syndicate or to join a
criminal street gang or criminal syndicate.
  “12. The defendant committed the offense to prevent a
person’s cooperation with an official law enforcement
investigation, to prevent a person’s testimony in a court
proceeding, in retaliation for a person’s cooperation with
an official law enforcement investigation or in retaliation
for a person’s testimony in a court proceeding.
  “13. The offense was committed in a cold, calculated
manner without pretense of moral or legal justification.
  “14. The defendant used a remote stun gun or an au-
thorized remote stun gun in the commission of the offense.

  [Note: Since 2001, the Arizona Legislature has added
aggravators 11 through 14.]
