(Slip Opinion)              OCTOBER TERM, 2010                                       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

        CULLEN, ACTING WARDEN v. PINHOLSTER

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

    No. 09–1088. Argued November 9, 2010—Decided April 4, 2011
A California jury convicted respondent Pinholster on two counts of first
  degree murder. At the penalty phase before the same jury, the prose
  cution produced eight witnesses, who testified about Pinholster’s his
  tory of threatening and violent behavior. Pinholster’s trial counsel,
  who unsuccessfully sought to exclude the aggravating evidence on the
  ground that the prosecution had not given Pinholster proper notice
  under California law, called only Pinholster’s mother. Counsel did
  not call a psychiatrist, though they had consulted with Dr. Stalberg,
  who had diagnosed Pinholster with antisocial personality disorder.
  The jury recommended the death penalty, and Pinholster was sen
  tenced to death. Pinholster twice sought habeas relief in the Califor
  nia Supreme Court, alleging, inter alia, that his trial counsel had
  failed to adequately investigate and present mitigating evidence dur
  ing the penalty phase. He introduced additional evidence to support
  his claim: school, medical, and legal records; and declarations from
  family members, one of his trial attorneys, and Dr. Woods, a psychia
  trist who diagnosed him with bipolar mood disorder and seizure dis
  orders, and who criticized Dr. Stalberg’s report. Each time, the State
  Supreme Court unanimously and summarily denied the claim on the
  merits. Subsequently, a Federal District Court held an evidentiary
  hearing and granted Pinholster federal habeas relief under 28
  U. S. C. §2254. Affirming, the en banc Ninth Circuit considered the
  new evidence adduced in the District Court hearing and held that the
  State Supreme Court’s decision “involved an unreasonable applica
  tion of . . . clearly established Federal law,” §2254(d)(1).
Held:
    1. Review under §2254(d)(1) is limited to the record that was before
 the state court that adjudicated the claim on the merits. Pp. 8–14.
2                       CULLEN v. PINHOLSTER

                                  Syllabus

          (a) As amended by the Antiterrorism and Effective Death Pen
    alty Act of 1996 (AEDPA), §2254 sets several limits on a federal
    court’s power to grant habeas relief to a state prisoner. As relevant
    here, a claim that has been “adjudicated on the merits in State court
    proceedings,” “shall not be granted . . . unless the adjudication” “(1)
    resulted in a decision that was contrary to, or involved an unreason
    able application of, clearly established Federal law,” or “(2) resulted
    in a decision that was based on an unreasonable determination of the
    facts in light of the evidence presented in the State court proceeding.”
    §2254(d). This “difficult to meet,” Harrington v. Richter, 562 U. S.
    ___, ___, and “ ‘highly deferential standard’ . . . demands that state
    court decisions be given the benefit of the doubt,” Woodford v. Vis
    ciotti, 537 U. S. 19, 24. Section 2254(d)(1)’s backward-looking lan
    guage—“resulted in” and “involved”—requires an examination of the
    state-court decision at the time it was made. It follows that the re
    cord under review is also limited to the record in existence at that
    same time—i.e., the state-court record. This understanding is com
    pelled by “the broader context of the statute as a whole,” which dem
    onstrates Congress’ intent to channel prisoners’ claims first to state
    courts. Robinson v. Shell Oil Co., 519 U. S. 337, 341. It is also con
    sistent with this Court’s precedents, which emphasize that
    §2254(d)(1) review focuses on what a state court knew and did. See,
    e.g., Lockyer v. Andrade, 538 U. S. 63, 71–72. Moreover, it is consis
    tent with Schriro v. Landrigan, 550 U. S. 465, 474, which explained
    that a federal habeas court is “not required to hold an evidentiary
    hearing” when the state-court record “precludes habeas relief” under
    §2254(d)’s limitations. The Ninth Circuit wrongly interpreted Wil
    liams v. Taylor, 529 U. S. 420, and Holland v. Jackson, 542 U. S. 649,
    as supporting the contrary view. Pp. 8–12.
          (b) This holding does not render superfluous §2254(e)(2)—which
    limits the federal habeas courts’ discretion to take new evidence in an
    evidentiary hearing. At a minimum, §2254(e)(2) still restricts their
    discretion in claims that were not adjudicated on the merits in state
    court. Although state prisoners may sometimes submit new evidence
    in federal court, AEDPA’s statutory scheme is designed to strongly
    discourage them from doing so. Pp. 13–14.
          (c) Remand for a properly limited review is inappropriate here,
    because the Ninth Circuit ruled, in the alternative, that Pinholster
    merited habeas relief on the state-court record alone. P. 14.
       2. On the record before the state court, Pinholster was not entitled
    to federal habeas relief. Pp. 14‘–31.
          (a) To satisfy §2254(d)(1)’s “unreasonable application” prong, he
    must show that “there was no reasonable basis” for the State Su
    preme Court’s summary decision. Richter, supra, at ___. Pp. 15–16.
                   Cite as: 563 U. S. ____ (2011)                     3

                              Syllabus

     (b) Strickland v. Washington, 466 U. S. 668, provides the clearly
established federal law here. To overcome the strong presumption
that counsel has acted competently, id., at 690, a defendant must
show that counsel failed to act “reasonabl[y] considering all the cir
cumstances,” id., at 688, and must prove the “reasonable probability
that, but for counsel’s unprofessional errors, the result of the proceed
ing would have been different,” id., at 694. Review here is thus “dou
bly deferential,” Knowles v. Mirzayance, 556 U. S. ___, ___, requiring
a “highly deferential” look at counsel’s performance, Strickland, su
pra, at 689, through §2254(d)’s “deferential lens,” Mirzayance, supra,
at ___, n. 2. Pp. 16–18.
     (c) Pinholster has not shown that the State Supreme Court’s de
cision that he could not demonstrate deficient performance by his
trial counsel necessarily involved an unreasonable application of fed
eral law. Pp. 18–26.
        (1) The state-court record supports the idea that his counsel
acted strategically to get the prosecution’s aggravation witnesses ex
cluded for lack of notice, and if that failed, to put on his mother as a
mitigation witness. Billing records show that they spent time inves
tigating mitigating evidence. The record also shows that they had an
unsympathetic client who had boasted about his criminal history dur
ing the guilt phase, leaving them with limited mitigation strategies.
In addition, when Dr. Stalberg concluded that Pinholster had no sig
nificant mental disorder or defect, he was aware of Pinholster’s medi
cal and social history. Given these impediments, it would have been
a reasonable penalty-phase strategy to focus on evoking sympathy for
Pinholster’s mother. Pinholster has responded with only a handful of
post-hoc nondenials by one of his lawyers. Pp. 18–23.
        (2) The Ninth Circuit misapplied Strickland when it drew from
this Court’s recent cases a “constitutional duty to investigate” and a
principle that it was prima facie ineffective for counsel to abandon an
investigation based on rudimentary knowledge of Pinholster’s back
ground. Beyond the general requirement of reasonableness, “specific
guidelines are not appropriate” under Strickland. 466 U. S., at 688.
Nor did the Ninth Circuit properly apply the strong presumption of
competence mandated by Strickland. Pp. 23–26.
     (d) Even if his trial counsel had performed deficiently, Pinholster
also has failed to show that the State Supreme Court must have un
reasonably concluded that he was not prejudiced. Pp. 26–31.
        (1) To determine “whether there is a reasonable probability
that, absent the errors, the sentencer . . . would have concluded that”
death was not warranted, Strickland, supra, at 695, the aggravating
evidence is reweighed “against the totality of available mitigating
evidence,” Wiggins v. Smith, 539 U. S. 510, 534. Here, the State pre
4                       CULLEN v. PINHOLSTER

                                 Syllabus

    sented extensive aggravating evidence at both the guilt and penalty
    phases. The mitigating evidence consisted primarily of the penalty
    phase testimony of Pinholster’s mother and guilt-phase testimony
    given by his brother. After considering the evidence, the jury re
    turned a sentence of death, which the state trial court found sup
    ported overwhelmingly by the weight of the evidence. Pp. 26–29.
           (2) There is no reasonable probability that the additional evi
    dence presented at Pinholster’s state proceedings would have
    changed the verdict. The “new” evidence largely duplicated the miti
    gation evidence of his mother and brother at trial. To the extent that
    there were new factual allegations or evidence, much of it is of ques
    tionable mitigating value. Dr. Woods’ testimony would have opened
    the door to rebuttal by a state expert; and new evidence relating to
    Pinholster’s substance abuse, mental illness, and criminal problems
    could lead a jury to conclude that he was beyond rehabilitation. The
    remaining new material in the state habeas record is sparse. Given
    what little additional mitigating evidence Pinholster presented in
    state habeas, the Court cannot say that the State Supreme Court’s
    determination was unreasonable. Pp. 29–30.
           (3) Because this Court did not apply AEDPA deference to the
    question of prejudice in Williams v. Taylor, 529 U. S. 362, and Rom
    pilla v. Beard, 545 U. S. 374, those cases lack the important “doubly
    deferential” standard of Strickland and AEDPA, and thus offer no
    guidance with respect to whether a state court has unreasonably de
    termined that prejudice is lacking. Pp. 30–31.
590 F. 3d 651, reversed.

   THOMAS, J., delivered the opinion of the Court, in which ROBERTS,
C. J., and SCALIA and KENNEDY, JJ., joined in full; in which ALITO, J.,
joined as to all but Part II; in which BREYER, J., joined as to Parts I and
II; and in which GINSBURG and KAGAN, JJ., joined as to Part II. ALITO,
J., filed an opinion concurring in part and concurring in the judgment.
BREYER, J., filed an opinion concurring in part and dissenting in part.
SOTOMAYOR, J., filed a dissenting opinion, in which GINSBURG and KA-
GAN, JJ., joined as to Part II.
                        Cite as: 563 U. S. ____ (2011)                              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. 09–1088
                                   _________________


VINCENT CULLEN, ACTING WARDEN, PETITIONER
         v. SCOTT LYNN PINHOLSTER
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

            APPEALS FOR THE NINTH CIRCUIT

                                 [April 4, 2011]


   JUSTICE THOMAS delivered the opinion of the Court.*
   Scott Lynn Pinholster and two accomplices broke into a
house in the middle of the night and brutally beat and
stabbed to death two men who happened to interrupt the
burglary. A jury convicted Pinholster of first-degree mur­
der, and he was sentenced to death.
   After the California Supreme Court twice unanimously
denied Pinholster habeas relief, a Federal District Court
held an evidentiary hearing and granted Pinholster ha­
beas relief under 28 U. S. C. §2254. The District Court
concluded that Pinholster’s trial counsel had been consti­
tutionally ineffective at the penalty phase of trial. Sitting
en banc, the Court of Appeals for the Ninth Circuit af­
firmed. Pinholster v. Ayers, 590 F. 3d 651 (2009). Consid­
ering the new evidence adduced in the District Court
hearing, the Court of Appeals held that the California
Supreme Court’s decision “was contrary to, or involved an
unreasonable application of, clearly established Federal
law.” §2254(d)(1).
   We granted certiorari and now reverse.
——————
 *JUSTICE GINSBURG and JUSTICE KAGAN join only Part II.
2                  CULLEN v. PINHOLSTER

                      Opinion of the Court

                               I

                               A

  On the evening of January 8, 1982, Pinholster solicited
Art Corona and Paul David Brown to help him rob Mi­
chael Kumar, a local drug dealer. On the way, they
stopped at Lisa Tapar’s house, where Pinholster put his
buck knife through her front door and scratched a swas­
tika into her car after she refused to talk to him. The
three men, who were all armed with buck knives, found no
one at Kumar’s house, broke in, and began ransacking the
home. They came across only a small amount of mari­
juana before Kumar’s friends, Thomas Johnson and
Robert Beckett, arrived and shouted that they were calling
the police.
  Pinholster and his accomplices tried to escape through
the rear door, but Johnson blocked their path. Pinholster
backed Johnson onto the patio, demanding drugs and
money and repeatedly striking him in the chest. Johnson
dropped his wallet on the ground and stopped resisting.
Beckett then came around the corner, and Pinholster
attacked him, too, stabbing him repeatedly in the chest.
Pinholster forced Beckett to the ground, took both men’s
wallets, and began kicking Beckett in the head. Mean­
while, Brown stabbed Johnson in the chest, “ ‘bury[ing] his
knife to the hilt.’ ” 35 Reporter’s Tr. 4947 (hereinafter Tr.).
Johnson and Beckett died of their wounds.
  Corona drove the three men to Pinholster’s apartment.
While in the car, Pinholster and Brown exulted, “ ‘We got
’em, man, we got ’em good.’ ” Ibid. At the apartment,
Pinholster washed his knife, and the three split the pro­
ceeds of the robbery: $23 and one quarter-ounce of mari­
juana. Although Pinholster instructed Corona to “lay
low,” Corona turned himself in to the police two weeks
later. Id., at 4955. Pinholster was arrested shortly there­
after and threatened to kill Corona if he did not keep quiet
about the burglary and murders. Corona later became the
                 Cite as: 563 U. S. ____ (2011)            3

                     Opinion of the Court

State’s primary witness. The prosecution brought numer­
ous charges against Pinholster, including two counts of
first-degree murder.
                             B
  The California trial court appointed Harry Brainard and
Wilbur Dettmar to defend Pinholster on charges of first­
degree murder, robbery, and burglary. Before their ap­
pointment, Pinholster had rejected other attorneys and
insisted on representing himself. During that time, the
State had mailed Pinholster a letter in jail informing him
that the prosecution planned to offer aggravating evidence
during the penalty phase of trial to support a sentence of
death.
  The guilt phase of the trial began on February 28, 1984.
Pinholster testified on his own behalf and presented an
alibi defense. He claimed that he had broken into
Kumar’s house alone at around 8 p.m. on January 8, 1982,
and had stolen marijuana but denied killing anyone.
Pinholster asserted that later that night around 1 a.m.,
while he was elsewhere, Corona went to Kumar’s house to
steal more drugs and did not return for three hours.
Pinholster told the jury that he was a “professional rob­
ber,” not a murderer. 43 id., at 6204. He boasted of com­
mitting hundreds of robberies over the previous six years
but insisted that he always used a gun, never a knife. The
jury convicted Pinholster on both counts of first-degree
murder.
  Before the penalty phase, Brainard and Dettmar moved
to exclude any aggravating evidence on the ground that
the prosecution had failed to provide notice of the evidence
to be introduced, as required by Cal. Penal Code Ann.
§190.3 (West 2008). At a hearing on April 24, Dettmar
argued that, in reliance on the lack of notice, he was “not
presently prepared to offer anything by way of mitigation.”
52 Tr. 7250. He acknowledged, however, that the prosecu­
4                CULLEN v. PINHOLSTER

                    Opinion of the Court

tor “possibly ha[d] met the [notice] requirement.” Ibid.
The trial court asked whether a continuance might be
helpful, but Dettmar declined, explaining that he could
not think of a mitigation witness other than Pinholster’s
mother and that additional time would not “make a great
deal of difference.” Id., at 7257–7258. Three days later,
after hearing testimony, the court found that Pinholster
had received notice while representing himself and denied
the motion to exclude.
  The penalty phase was held before the same jury that
had convicted Pinholster. The prosecution produced eight
witnesses, who testified about Pinholster’s history of
threatening and violent behavior, including resisting
arrest and assaulting police officers, involvement with
juvenile gangs, and a substantial prison disciplinary
record. Defense counsel called only Pinholster’s mother,
Burnice Brashear. She gave an account of Pinholster’s
troubled childhood and adolescent years, discussed Pin­
holster’s siblings, and described Pinholster as “a perfect
gentleman at home.” Id., at 7405. Defense counsel did not
call a psychiatrist, though they had consulted Dr. John
Stalberg at least six weeks earlier. Dr. Stalberg noted
Pinholster’s “psychopathic personality traits,” diagnosed
him with antisocial personality disorder, and concluded
that he “was not under the influence of extreme mental or
emotional disturbance” at the time of the murders. App.
131.
  After 2½ days of deliberation, the jury unanimously
voted for death on each of the two murder counts. On
mandatory appeal, the California Supreme Court affirmed
the judgment. People v. Pinholster, 1 Cal. 4th 865, 824
P. 2d 571 (1992).
                           C
  In August 1993, Pinholster filed his first state habeas
petition. Represented by new counsel, Pinholster alleged,
                    Cite as: 563 U. S. ____ (2011)                  5

                        Opinion of the Court

inter alia, ineffective assistance of counsel at the penalty
phase of his trial. He alleged that Brainard and Dettmar
had failed to adequately investigate and present mitigat­
ing evidence, including evidence of mental disorders.
Pinholster supported this claim with school, medical, and
legal records, as well as declarations from family mem­
bers, Brainard, and Dr. George Woods, a psychiatrist who
diagnosed Pinholster with bipolar mood disorder and
seizure disorders. Dr. Woods criticized Dr. Stalberg’s
report as incompetent, unreliable, and inaccurate. The
California Supreme Court unanimously and summarily1
denied Pinholster’s penalty-phase ineffective-assistance
claim “on the substantive ground that it is without merit.”
App. to Pet. for Cert. 302.
  Pinholster filed a federal habeas petition in April 1997.
He reiterated his previous allegations about penalty-phase
ineffective assistance and also added new allegations that
his trial counsel had failed to furnish Dr. Stalberg with
adequate background materials. In support of the new
allegations, Dr. Stalberg provided a declaration stating
that in 1984, Pinholster’s trial counsel had provided him
with only some police reports and a 1978 probation report.
Dr. Stalberg explained that, had he known about the
material that had since been gathered by Pinholster’s
habeas counsel, he would have conducted “further inquiry”
before concluding that Pinholster suffered only from a
personality disorder. App. to Brief in Opposition 219. He
noted that Pinholster’s school records showed evidence of
“some degree of brain damage.” Ibid. Dr. Stalberg did
not, however, retract his earlier diagnosis. The parties
stipulated that this declaration had never been submitted
to the California Supreme Court, and the federal petition
——————
  1 Although the California Supreme Court initially issued an order

asking the State to respond, it ultimately withdrew that order as “im-
providently issued.” App. to Pet. for Cert. 302.
6                     CULLEN v. PINHOLSTER

                         Opinion of the Court

was held in abeyance to allow Pinholster to go back to
state court.
   In August 1997, Pinholster filed his second state habeas
petition, this time including Dr. Stalberg’s declaration and
requesting judicial notice of the documents previously
submitted in support of his first state habeas petition. His
allegations of penalty-phase ineffective assistance of coun­
sel mirrored those in his federal habeas petition. The
California Supreme Court again unanimously and sum­
marily denied the petition “on the substantive ground that
it is without merit.”2 App. to Pet. for Cert. 300.
   Having presented Dr. Stalberg’s declaration to the state
court, Pinholster returned to the District Court. In No­
vember 1997, he filed an amended petition for a writ of
habeas corpus. His allegations of penalty-phase ineffec­
tive assistance of counsel were identical to those in his
second state habeas petition. Both parties moved for
summary judgment and Pinholster also moved, in the
alternative, for an evidentiary hearing.
   The District Court concluded that the Antiterrorism and
Effective Death Penalty Act of 1996 (AEDPA), 110 Stat.
1214, did not apply and granted an evidentiary hearing.
Before the hearing, the State deposed Dr. Stalberg, who
stated that none of the new material he reviewed altered
his original diagnosis. Dr. Stalberg disagreed with Dr.
Woods’ conclusion that Pinholster suffers from bipolar
disorder. Pinholster did not call Dr. Stalberg to testify at
the hearing. He presented two new medical experts: Dr.
Sophia Vinogradov, a psychiatrist who diagnosed Pinhol­
ster with organic personality syndrome and ruled out
antisocial personality disorder, and Dr. Donald Olson, a
——————
  2 A majority also “[s]eparately and independently” denied several

claims, including penalty-phase ineffective assistance of counsel, as
untimely, successive, and barred by res judicata. Id., at 300. The State
has not argued that these procedural rulings constitute adequate and
independent state grounds that bar federal habeas review.
                 Cite as: 563 U. S. ____ (2011)           7

                     Opinion of the Court

pediatric neurologist who suggested that Pinholster suf­
fers from partial epilepsy and brain injury. The State
called Dr. F. David Rudnick, a psychiatrist who, like Dr.
Stalberg, diagnosed Pinholster with antisocial personality
disorder and rejected any diagnosis of bipolar disorder.
                              D
   The District Court granted habeas relief. Applying pre-
AEDPA standards, the court granted the habeas petition
“for inadequacy of counsel by failure to investigate and
present mitigation evidence at the penalty hearing.” App.
to Pet. for Cert. 262. After Woodford v. Garceau, 538 U. S.
202 (2003), clarified that AEDPA applies to cases like
Pinholster’s, the court amended its order but did not alter
its conclusion. Over a dissent, a panel of the Court of
Appeals for the Ninth Circuit reversed. Pinholster v.
Ayers, 525 F. 3d 742 (2008).
   On rehearing en banc, the Court of Appeals vacated the
panel opinion and affirmed the District Court’s grant of
habeas relief. The en banc court held that the District
Court’s evidentiary hearing was not barred by 28 U. S. C.
§2254(e)(2). The court then determined that new evidence
from the hearing could be considered in assessing whether
the California Supreme Court’s decision “was contrary to,
or involved an unreasonable application of, clearly estab­
lished Federal law” under §2254(d)(1). See 590 F. 3d, at
666 (“Congress did not intend to restrict the inquiry under
§2254(d)(1) only to the evidence introduced in the state
habeas court”). Taking the District Court evidence into
account, the en banc court determined that the California
Supreme Court unreasonably applied Strickland v. Wash
ington, 466 U. S. 668 (1984), in denying Pinholster’s claim
of penalty-phase ineffective assistance of counsel.
   Three judges dissented and rejected the majority’s
conclusion that the District Court hearing was not barred
by §2254(e)(2). 590 F. 3d, at 689 (opinion of Kozinski,
8                 CULLEN v. PINHOLSTER

                     Opinion of the Court

C. J.) (characterizing Pinholster’s efforts as “habeas-by­
sandbagging”). Limiting its review to the state-court
record, the dissent concluded that the California Supreme
Court did not unreasonably apply Strickland. 590 F. 3d,
at 691–723.
   We granted certiorari to resolve two questions. 560
U. S. ___ (2010). First, whether review under §2254(d)(1)
permits consideration of evidence introduced in an eviden­
tiary hearing before the federal habeas court. Second,
whether the Court of Appeals properly granted Pinholster
habeas relief on his claim of penalty-phase ineffective
assistance of counsel.
                            II
  We first consider the scope of the record for a
§2254(d)(1) inquiry. The State argues that review is
limited to the record that was before the state court that
adjudicated the claim on the merits. Pinholster contends
that evidence presented to the federal habeas court may
also be considered. We agree with the State.
                              A
   As amended by AEDPA, 28 U. S. C. §2254 sets several
limits on the power of a federal court to grant an applica­
tion for a writ of habeas corpus on behalf of a state pris­
oner. Section 2254(a) permits a federal court to entertain
only those applications alleging that a person is in state
custody “in violation of the Constitution or laws or treaties
of the United States.” Sections 2254(b) and (c) provide
that a federal court may not grant such applications
unless, with certain exceptions, the applicant has ex­
hausted state remedies.
   If an application includes a claim that has been “adjudi­
cated on the merits in State court proceedings,” §2254(d),
an additional restriction applies. Under §2254(d), that
application “shall not be granted with respect to [such a]
                  Cite as: 563 U. S. ____ (2011)           9

                      Opinion of the Court

claim . . . unless the adjudication of the claim”:
       “(1) resulted in a decision that was contrary to, or
    involved an unreasonable application of, clearly estab­
    lished Federal law, as determined by the Supreme
    Court of the United States; or
       “(2) resulted in a decision that was based on an un­
    reasonable determination of the facts in light of the
    evidence presented in the State court proceeding.”
This is a “difficult to meet,” Harrington v. Richter, 562
U. S. ___, ___ (2011) (slip op., at 12), and “highly deferen­
tial standard for evaluating state-court rulings, which
demands that state-court decisions be given the benefit of
the doubt,” Woodford v. Visciotti, 537 U. S. 19, 24 (2002)
(per curiam) (citation and internal quotation marks omit­
ted). The petitioner carries the burden of proof. Id., at 25.
   We now hold that review under §2254(d)(1) is limited to
the record that was before the state court that adjudicated
the claim on the merits. Section 2254(d)(1) refers, in the
past tense, to a state-court adjudication that “resulted in”
a decision that was contrary to, or “involved” an unrea­
sonable application of, established law. This backward­
looking language requires an examination of the state­
court decision at the time it was made. It follows that the
record under review is limited to the record in existence at
that same time⎯i.e., the record before the state court.
   This understanding of the text is compelled by “the
broader context of the statute as a whole,” which demon­
strates Congress’ intent to channel prisoners’ claims first
to the state courts. Robinson v. Shell Oil Co., 519 U. S.
337, 341 (1997). “The federal habeas scheme leaves pri­
mary responsibility with the state courts . . . .” Visciotti,
supra, at 27. Section 2254(b) requires that prisoners must
ordinarily exhaust state remedies before filing for federal
habeas relief. It would be contrary to that purpose to
allow a petitioner to overcome an adverse state-court
10                    CULLEN v. PINHOLSTER

                         Opinion of the Court

decision with new evidence introduced in a federal habeas
court and reviewed by that court in the first instance
effectively de novo.
  Limiting §2254(d)(1) review to the state-court record is
consistent with our precedents interpreting that statu­
tory provision. Our cases emphasize that review under
§2254(d)(1) focuses on what a state court knew and did.
State-court decisions are measured against this Court’s
precedents as of “the time the state court renders its deci­
sion.” Lockyer v. Andrade, 538 U. S. 63, 71–72 (2003). To
determine whether a particular decision is “contrary to”
then-established law, a federal court must consider
whether the decision “applies a rule that contradicts
[such] law” and how the decision “confronts [the] set of
facts” that were before the state court. Williams v. Taylor,
529 U. S. 362, 405, 406 (2000) (Terry Williams). If the
state-court decision “identifies the correct governing legal
principle” in existence at the time, a federal court must
assess whether the decision “unreasonably applies that
principle to the facts of the prisoner’s case.” Id., at 413. It
would be strange to ask federal courts to analyze whether
a state court’s adjudication resulted in a decision that
unreasonably applied federal law to facts not before the
state court.3
——————
  3 JUSTICE SOTOMAYOR argues that there is nothing strange about al­

lowing consideration of new evidence under §2254(d)(1) because, in her
view, it would not be “so different” from some other tasks that courts
undertake. Post, at 13 (dissenting opinion). What makes the consid­
eration of new evidence strange is not how “different” the task would
be, but rather the notion that a state court can be deemed to have
unreasonably applied federal law to evidence it did not even know
existed. We cannot comprehend how exactly a state court would have
any control over its application of law to matters beyond its knowledge.
Adopting JUSTICE SOTOMAYOR’s approach would not take seriously
AEDPA’s requirement that federal courts defer to state-court decisions
and would effectively treat the statute as no more than a “ ‘mood’ that
the Federal Judiciary must respect,” Terry Williams, 529 U. S., at 386
                     Cite as: 563 U. S. ____ (2011)                  11

                         Opinion of the Court

   Our recent decision in Schriro v. Landrigan, 550 U. S.
465 (2007), is consistent as well with our holding here. We
explained that “[b]ecause the deferential standards pre­
scribed by §2254 control whether to grant habeas relief, a
federal court must take into account those standards in
deciding whether an evidentiary hearing is appropriate.”
Id., at 474. In practical effect, we went on to note, this
means that when the state-court record “precludes habeas
relief” under the limitations of §2254(d), a district court is
“not required to hold an evidentiary hearing.” Id., at 474
(citing with approval the Ninth Circuit’s recognition that
“an evidentiary hearing is not required on issues that can
be resolved by reference to the state court record” (internal
quotation marks omitted)).
   The Court of Appeals wrongly interpreted Williams v.
Taylor, 529 U. S. 420 (2000) (Michael Williams), as sup­
porting the contrary view.        The question there was
whether the lower court had correctly determined that
§2254(e)(2) barred the petitioner’s request for a federal
evidentiary hearing.4 Michael Williams did not concern
whether evidence introduced in such a hearing could be
considered under §2254(d)(1). In fact, only one claim at
issue in that case was even subject to §2254(d); the rest
had not been adjudicated on the merits in state-court
proceedings. See id., at 429 (“Petitioner did not develop,
or raise, his claims . . . until he filed his federal habeas
petition”).5
——————
(opinion of Stevens, J.).
  4 If a prisoner has “failed to develop the factual basis of a claim in

State court proceedings,” §2254(e)(2) bars a federal court from holding
an evidentiary hearing, unless the applicant meets certain statutory
requirements.
  5 JUSTICE SOTOMAYOR’s suggestion that Michael Williams “rejected”

the conclusion here, see post, at 15, is thus quite puzzling. In the
passage that she quotes, see ibid., the Court merely explains that
§2254(e)(2) should be interpreted in a way that does not preclude a
state prisoner, who was diligent in state habeas court and who can
12                    CULLEN v. PINHOLSTER

                         Opinion of the Court

   If anything, the decision in Michael Williams supports
our holding. The lower court in that case had determined
that the one claim subject to §2254(d)(1) did not satisfy
that statutory requirement. In light of that ruling, this
Court concluded that it was “unnecessary to reach the
question whether §2254(e)(2) would permit a [federal]
hearing on th[at] claim.” Id., at 444. That conclusion is
fully consistent with our holding that evidence later intro­
duced in federal court is irrelevant to §2254(d)(1) review.
   The Court of Appeals’ reliance on Holland v. Jackson,
542 U. S. 649 (2004) (per curiam), was also mistaken. In
Holland, we initially stated that “whether a state court’s
decision was unreasonable [under §2254(d)(1)] must be
assessed in light of the record the court had before it.” Id.,
at 652. We then went on to assume for the sake of argu­
ment what some Courts of Appeals had held⎯that
§2254(d)(1), despite its mandatory language, simply does
not apply when a federal habeas court has admitted new
evidence that supports a claim previously adjudicated in
state court.6 Id., at 653. There was no reason to decide
that question because regardless, the hearing should have
been barred by §2254(e)(2). Today, we reject that assump­
tion and hold that evidence introduced in federal court
has no bearing on §2254(d)(1) review. If a claim has
been adjudicated on the merits by a state court, a fed­
eral habeas petitioner must overcome the limitation of
§2254(d)(1) on the record that was before that state court.7
——————
satisfy §2254(d), from receiving an evidentiary hearing.
  6 In Bradshaw v. Richey, 546 U. S. 74 (2005) (per curiam), on which

the Court of Appeals also relied, we made the same assumption. Id., at
79–80 (discussing the State’s “Holland argument”).
  7 Pinholster and JUSTICE SOTOMAYOR place great weight on the fact

that §2254(d)(2) includes the language “in light of the evidence pre­
sented in the State court proceeding,” whereas §2254(d)(1) does not.
See post, at 6–7. The additional clarity of §2254(d)(2) on this point,
however, does not detract from our view that §2254(d)(1) also is plainly
limited to the state-court record. The omission of clarifying language
                     Cite as: 563 U. S. ____ (2011) 
                  13

                          Opinion of the Court 


                                B

   Pinholster’s contention that our holding renders
§2254(e)(2) superfluous is incorrect. Section 2254(e)(2)
imposes a limitation on the discretion of federal habeas
courts to take new evidence in an evidentiary hearing.
See Landrigan, supra, at 473 (noting that district courts,
under AEDPA, generally retain the discretion to grant an
evidentiary hearing). Like §2254(d)(1), it carries out
“AEDPA’s goal of promoting comity, finality, and federal­
ism by giving state courts the first opportunity to review
[a] claim, and to correct any constitutional violation in the
first instance.” Jimenez v. Quarterman, 555 U. S. 113, ___
(2009) (slip op., at 8) (internal quotation marks omitted).8
   Section 2254(e)(2) continues to have force where
§2254(d)(1) does not bar federal habeas relief. For exam­
ple, not all federal habeas claims by state prisoners fall
within the scope of §2254(d), which applies only to claims
“adjudicated on the merits in State court proceedings.” At
a minimum, therefore, §2254(e)(2) still restricts the discre­
tion of federal habeas courts to consider new evidence
when deciding claims that were not adjudicated on the
merits in state court. See, e.g., Michael Williams, 529
U. S., at 427–429.9
   Although state prisoners may sometimes submit new
——————
from §2254(d)(1) just as likely reflects Congress’ belief that such lan­
guage was unnecessary as it does anything else.
  8 JUSTICE SOTOMAYOR’s argument that §2254(d)(1) must be read in a

way that “accommodates” §2254(e)(2), see post, at 9, rests on a funda­
mental misunderstanding of §2254(e)(2). The focus of that section is
not on “preserving the opportunity” for hearings, post, at 9, but rather
on limiting the discretion of federal district courts in holding hearings.
We see no need in this case to address the proper application of
§2254(e)(2). See n. 20, infra. But see post, at 12 (suggesting that we
have given §2254(e)(2) “an unnaturally cramped reading”).
  9 In all events, of course, the requirements of §§2254(a) through (c)

remain significant limitations on the power of a federal court to grant
habeas relief.
14                   CULLEN v. PINHOLSTER

                        Opinion of the Court

evidence in federal court, AEDPA’s statutory scheme is
designed to strongly discourage them from doing so.
Provisions like §§2254(d)(1) and (e)(2) ensure that
“[f]ederal courts sitting in habeas are not an alternative
forum for trying facts and issues which a prisoner made
insufficient effort to pursue in state proceedings.” Id., at
437; see also Richter, 562 U. S., at ___ (slip op., at 13)
(“Section 2254(d) is part of the basic structure of federal
habeas jurisdiction, designed to confirm that state courts
are the principal forum for asserting constitutional chal­
lenges to state convictions”); Wainwright v. Sykes, 433
U. S. 72, 90 (1977) (“[T]he state trial on the merits [should
be] the ‘main event,’ so to speak, rather than a ‘tryout on
the road’ for what will later be the determinative federal
habeas hearing”).10
                              C
  Accordingly, we conclude that the Court of Appeals
erred in considering the District Court evidence in its
review under §2254(d)(1). Although we might ordinarily
remand for a properly limited review, the Court of Appeals
also ruled, in the alternative, that Pinholster merited
habeas relief even on the state-court record alone. 590
F. 3d, at 669. Remand is therefore inappropriate, and we
turn next to a review of the state-court record.
                           III
  The Court of Appeals’ alternative holding was also
erroneous. Pinholster has failed to demonstrate that the
California Supreme Court unreasonably applied clearly
established federal law to his penalty-phase ineffective­
——————
  10 Though we do not decide where to draw the line between new

claims and claims adjudicated on the merits, see n. 11, infra, JUSTICE
SOTOMAYOR’s hypothetical involving new evidence of withheld exculpa­
tory witness statements, see post, at 9–10, may well present a new
claim.
                     Cite as: 563 U. S. ____ (2011)                    15

                          Opinion of the Court

assistance claim on the state-court record. Section 2254(d)
prohibits habeas relief.
                             A
  Section 2254(d) applies to Pinholster’s claim because
that claim was adjudicated on the merits in state-court
proceedings. No party disputes that Pinholster’s federal
petition alleges an ineffective-assistance-of-counsel claim
that had been included in both of Pinholster’s state habeas
petitions. The California Supreme Court denied each of
those petitions “on the substantive ground that it is with­
out merit.”11
  Section 2254(d) applies even where there has been a
summary denial. See Richter, 562 U. S., at ___ (slip op., at
8). In these circumstances, Pinholster can satisfy the
“unreasonable application” prong of §2254(d)(1) only by
showing that “there was no reasonable basis” for the
California Supreme Court’s decision. Id., at ___ (slip op.,
at 8). “[A] habeas court must determine what arguments
or theories . . . could have supporte[d] the state court’s
decision; and then it must ask whether it is possible fair­
minded jurists could disagree that those arguments or
——————
  11 The State does not contest that the alleged claim was adjudicated

on the merits by the California Supreme Court, but it asserts that some
of the evidence adduced in the federal evidentiary hearing fundamen­
tally changed Pinholster’s claim so as to render it effectively unadjudi­
cated. See Brief for Petitioner 28–31; Reply Brief for Petitioner 4–5; Tr.
of Oral Arg. 18. Pinholster disagrees and argues that the evidence
adduced in the evidentiary hearing simply supports his alleged claim.
Brief for Respondent 33–37.
  We need not resolve this dispute because, even accepting Pinholster’s
position, he is not entitled to federal habeas relief. Pinholster has
failed to show that the California Supreme Court unreasonably applied
clearly established federal law on the record before that court, infra, at
18–23, 26–30, which brings our analysis to an end. Even if the evi­
dence adduced in the District Court additionally supports his claim, as
Pinholster contends, we are precluded from considering it. See n. 20,
infra.
16                     CULLEN v. PINHOLSTER

                          Opinion of the Court

theories are inconsistent with the holding in a prior deci­
sion of this Court.” Id., at ___ (slip op., at 12). After a
thorough review of the state-court record,12 we conclude
that Pinholster has failed to meet that high threshold.
                            B
  There is no dispute that the clearly established federal
law here is Strickland v. Washington. In Strickland, this
Court made clear that “the purpose of the effective assis­
tance guarantee of the Sixth Amendment is not to improve
the quality of legal representation . . . [but] simply to
——————
   12 The parties agree that the state-court record includes both the

“allegations of [the] habeas corpus petition . . . and . . . ‘any matter of
record pertaining to the case.’ ” In re Hochberg, 2 Cal. 3d 870, 874, n. 2,
471 P. 2d 1, 3–4, n. 2 (1970) (quoting Cal. Rule of Court 60), rejected on
another ground by In re Fields, 51 Cal. 3d 1063, 1070, n. 3, 800 P. 2d
862, 866, n. 3 (1990); see Reply Brief for Petitioner 16–17; Tr. of Oral
Arg. 45. Under California law, the California Supreme Court’s sum­
mary denial of a habeas petition on the merits reflects that court’s
determination that “the claims made in th[e] petition do not state a
prima facie case entitling the petitioner to relief.” In re Clark, 5
Cal. 4th 750, 770, 855 P. 2d 729, 741–742 (1993). It appears that the
court generally assumes the allegations in the petition to be true, but
does not accept wholly conclusory allegations, People v. Duvall, 9
Cal. 4th 464, 474, 886 P. 2d 1252, 1258 (1995), and will also “review the
record of the trial . . . to assess the merits of the petitioner’s claims,”
Clark, supra, at 770, 855 P. 2d, at 742.
   The specific contents of the state-court record depend on which of the
two state habeas proceedings is at issue. One amicus curiae suggests
that both are at issue⎯that is, Pinholster must prove that both Cali­
fornia Supreme Court proceedings involved an unreasonable applica­
tion of law under §2254(d)(1). See Brief for Criminal Justice Legal
Foundation 26. By contrast, the most favorable approach for Pinholster
would be review of only the second state habeas proceeding, the record
of which includes all of the evidence that Pinholster ever submitted in
state habeas. We have not previously ruled on how to proceed in these
circumstances, and we need not do so here. Even taking the approach
most favorable to Pinholster, and reviewing only whether the California
Supreme Court was objectively unreasonable in the second state
habeas proceeding, we find that Pinholster has failed to satisfy
§2254(d)(1).
                  Cite as: 563 U. S. ____ (2011)            17

                      Opinion of the Court

ensure that criminal defendants receive a fair trial.” 466
U. S., at 689. Thus, “[t]he benchmark for judging any
claim of ineffectiveness must be whether counsel’s conduct
so undermined the proper functioning of the adversarial
process that the trial cannot be relied on as having pro­
duced a just result.” Id., at 686 (emphasis added). The
Court acknowledged that “[t]here are countless ways to
provide effective assistance in any given case,” and that
“[e]ven the best criminal defense attorneys would not
defend a particular client in the same way.” Id., at 689.
   Recognizing the “tempt[ation] for a defendant to second­
guess counsel’s assistance after conviction or adverse
sentence,” ibid., the Court established that counsel should
be “strongly presumed to have rendered adequate assis­
tance and made all significant decisions in the exercise of
reasonable professional judgment,” id., at 690. To over­
come that presumption, a defendant must show that
counsel failed to act “reasonabl[y] considering all the
circumstances.” Id., at 688. The Court cautioned that
“[t]he availability of intrusive post-trial inquiry into attor­
ney performance or of detailed guidelines for its evalua­
tion would encourage the proliferation of ineffectiveness
challenges.” Id., at 690.
   The Court also required that defendants prove preju­
dice. Id., at 691–692. “The defendant must show that
there is a reasonable probability that, but for counsel’s
unprofessional errors, the result of the proceeding would
have been different.” Id., at 694. “A reasonable probabil­
ity is a probability sufficient to undermine confidence in
the outcome.” Ibid. That requires a “substantial,” not just
“conceivable,” likelihood of a different result. Richter, 562
U. S., at ___ (slip op., at 22).
   Our review of the California Supreme Court’s decision is
thus “doubly deferential.” Knowles v. Mirzayance, 556
U. S. ___, ___ (2009) (slip op., at 11) (citing Yarborough v.
Gentry, 540 U. S. 1, 5–6 (2003) (per curiam)). We take a
18                CULLEN v. PINHOLSTER

                     Opinion of the Court

“highly deferential” look at counsel’s performance, Strick
land, supra, at 689, through the “deferential lens of
§2254(d),” Mirzayance, supra, at ___, n. 2 (slip op., at 9,
n. 2). Pinholster must demonstrate that it was necessarily
unreasonable for the California Supreme Court to con­
clude: (1) that he had not overcome the strong presump­
tion of competence; and (2) that he had failed to under­
mine confidence in the jury’s sentence of death.
                              C
                              1
   Pinholster has not shown that the California Supreme
Court’s decision that he could not demonstrate deficient
performance by his trial counsel necessarily involved an
unreasonable application of federal law. In arguing to the
state court that his counsel performed deficiently, Pinhol­
ster contended that they should have pursued and pre­
sented additional evidence about: his family members and
their criminal, mental, and substance abuse problems; his
schooling; and his medical and mental health history,
including his epileptic disorder. To support his allegation
that his trial counsel had “no reasonable tactical basis” for
the approach they took, Pinholster relied on statements
his counsel made at trial. App. to Brief in Opposition 143.
When arguing the motion to exclude the State’s aggravat­
ing evidence at the penalty phase for failure to comply
with Cal. Penal Code Ann. §190.3, Dettmar, one of Pinhol­
ster’s counsel, contended that because the State did not
provide notice, he “[was] not presently prepared to offer
anything by way of mitigation,” 52 Tr. 7250. In response
to the trial court’s inquiry as to whether a continuance
might be helpful, Dettmar noted that the only mitigation
witness he could think of was Pinholster’s mother. Addi­
tional time, Dettmar stated, would not “make a great deal
of difference.” Id., at 7257–7258.
   We begin with the premise that “under the circum­
                 Cite as: 563 U. S. ____ (2011)          19

                     Opinion of the Court

stances, the challenged action[s] might be considered
sound trial strategy. ” Strickland, supra, at 689 (internal
quotation marks omitted). The Court of Appeals dissent
described one possible strategy:
    “[Pinholster’s attorneys] were fully aware that they
    would have to deal with mitigation sometime during
    the course of the trial, did spend considerable time
    and effort investigating avenues for mitigation[,] and
    made a reasoned professional judgment that the best
    way to serve their client would be to rely on the fact
    that they never got [the required §190.3] notice and
    hope the judge would bar the state from putting on
    their aggravation witnesses.” 590 F. 3d, at 701–702
    (opinion of Kozinski, C. J.).
Further, if their motion was denied, counsel were pre­
pared to present only Pinholster’s mother in the penalty
phase to create sympathy not for Pinholster, but for his
mother. After all, the “ ‘family sympathy’ ” mitigation
defense was known to the defense bar in California at the
time and had been used by other attorneys. Id., at 707.
Rather than displaying neglect, we presume that Dett­
mar’s arguments were part of this trial strategy. See
Gentry, supra, at 8 (“[T]here is a strong presumption that
[counsel took certain actions] for tactical reasons rather
than through sheer neglect” (citing Strickland, supra, at
690)).
  The state-court record supports the idea that Pinhol­
ster’s counsel acted strategically to get the prosecution’s
aggravation witnesses excluded for lack of notice, and if
that failed, to put on Pinholster’s mother. Other state­
ments made during the argument regarding the motion to
exclude suggest that defense counsel were trying to take
advantage of a legal technicality and were not truly sur­
prised. Brainard and Dettmar acknowledged that the
prosecutor had invited them on numerous occasions to
20                     CULLEN v. PINHOLSTER

                          Opinion of the Court

review Pinholster’s state prison file but argued that such
an invitation did not meet with the “strict demands” of
§190.3. 52 Tr. 7260. Dettmar admitted that the prosecu­
tor, “being as thorough as she is, possibly ha[d] met the
requirement.” Id., at 7250. But if so, he wanted her “to
make that representation to the court.”13 Ibid.
   Timesheets indicate that Pinholster’s trial counsel
investigated mitigating evidence.14 Long before the guilty
verdict, Dettmar talked with Pinholster’s mother and
contacted a psychiatrist.15 On February 26, two months
before the penalty phase started, he billed six hours
for “[p]reparation argument, death penalty phase.” See
Clerk’s Tr. 864. Brainard, who merely assisted Dettmar
for the penalty phase, researched epilepsy and also inter­
viewed Pinholster’s mother.16 We know that Brainard
likely spent additional time, not reflected in these entries,
preparing Pinholster’s brother, Terry, who provided some
mitigation testimony about Pinholster’s background dur­

——————
  13 Counsel’s argument was persuasive enough to cause the trial court

to hold a hearing and take testimony before denying the motion to
exclude.
  14 Both parties agree that these billing records were before the Cali­

fornia Supreme Court. See Tr. of Oral Arg. 45, 48–49.
  15 See Clerk’s Tr. 798 (entry on Jan. 13 for “phone call to defendant’s

mother re medical history”); id., at 864 (entries on Feb. 21 for “Penal
Code research on capital punishment”; Feb. 23 for “conference with
defendant’s mother re childhood problems”; Feb. 25 for “Research on
Pen. C. 190.3”; and Feb. 29 for “photocopying reports for appointed
expert,” “Preparation of Declaration and Order for appointment of
psychiatrist,” “Preparation order of visitation for investigator,” and
“Further research on Pen. C. 190.3”). The time records for Dettmar
unfortunately stop with Mar. 14, so we do not know what he did during
the critical weeks leading up to the penalty phase on May 1.
  16 See id., at 869 (entries on Feb. 23 for “Conf. with Bernice Brasher,

Pinholster’s mother”; and Feb. 25 for “Research re; epilepsy and conf.
with nurse”); id., at 1160 (entries on Apr. 11 for “Start prep. for penalty
phase”; Apr. 25 for “Prep. penalty phase and conf. with Mrs. Brashear”;
and Apr. 26 for “Prep. penalty phase”).
                  Cite as: 563 U. S. ____ (2011)           21

                      Opinion of the Court

ing the guilt phase. Infra, at 28.
   The record also shows that Pinholster’s counsel con­
fronted a challenging penalty phase with an unsympa­
thetic client, which limited their feasible mitigation
strategies. By the end of the guilt phase, the jury had
observed Pinholster “glor[y]” in “his criminal disposition”
and “hundreds of robberies.” Pinholster, 1 Cal. 4th, at
945, 907, 824 P. 2d, at 611, 584. During his cross­
examination, Pinholster laughed or smirked when he told
the jury that his “occupation” was “a crook,” when he was
asked whether he had threatened a potential witness, and
when he described thwarting police efforts to recover a
gun he had once used. 44 Tr. 6225. He bragged about
being a “professional robber.” 43 id., at 6204. To sup-
port his defense, Pinholster claimed that he used only
guns⎯not knives⎯to commit his crimes. But during
cross-examination, Pinholster admitted that he had previ­
ously been convicted of using a knife in a kidnaping.
Pinholster also said he was a white supremacist and that
he frequently carved swastikas into other people’s prop­
erty as “a sideline to robbery.” 44 id., at 6246.
   Trial counsel’s psychiatric expert, Dr. Stalberg, had
concluded that Pinholster showed no significant signs or
symptoms of mental disorder or defect other than his
“psychopathic personality traits.” App. 131. Dr. Stalberg
was aware of Pinholster’s hyperactivity as a youngster,
hospitalization at age 14 for incorrigibility, alleged epilep­
tic disorder, and history of drug dependency. Neverthe­
less, Dr. Stalberg told counsel that Pinholster did not
appear to suffer from brain damage, was not significantly
intoxicated or impaired on the night in question, and did
not have an impaired ability to appreciate the criminality
of his conduct.
   Given these impediments, it would have been a reason­
able penalty-phase strategy to focus on evoking sympathy
for Pinholster’s mother. In fact, such a family sympathy
22                CULLEN v. PINHOLSTER

                     Opinion of the Court

defense is precisely how the State understood defense
counsel’s strategy. The prosecutor carefully opened her
cross-examination of Pinholster’s mother with, “I hope you
understand I don’t enjoy cross-examining a mother of
anybody.” 52 Tr. 7407. And in her closing argument, the
prosecutor attempted to undercut defense counsel’s strat­
egy by pointing out, “Even the most heinous person born,
even Adolph Hitler[,] probably had a mother who loved
him.” 53 id., at 7452.
   Pinholster’s only response to this evidence is a series of
declarations from Brainard submitted with Pinholster’s
first state habeas petition, seven years after the trial.
Brainard declares that he has “no recollection” of inter­
viewing any family members (other than Pinholster’s
mother) regarding penalty-phase testimony, of attempting
to secure Pinholster’s school or medical records, or of
interviewing any former teachers or counselors. Pet. for
Writ of Habeas Corpus in No. S004616 (Cal.), Exh. 3.
Brainard also declares that Dettmar was primarily re­
sponsible for mental health issues in the case, but he has
“no recollection” of Dettmar ever having secured Pinhol­
ster’s medical records. Id., Exh. 2. Dettmar neither con­
firmed nor denied Brainard’s statements, as he had died
by the time of the first state habeas petition. 590 F. 3d, at
700 (Kozinski, C. J., dissenting).
   In sum, Brainard and Dettmar made statements sug­
gesting that they were not surprised that the State in­
tended to put on aggravating evidence, billing records
show that they spent time investigating mitigating evi­
dence, and the record demonstrates that they represented
a psychotic client whose performance at trial hardly en­
deared him to the jury. Pinholster has responded to this
evidence with only a handful of post-hoc nondenials by one
of his lawyers. The California Supreme Court could have
reasonably concluded that Pinholster had failed to rebut
the presumption of competence mandated by Strickland—
                 Cite as: 563 U. S. ____ (2011)           23

                     Opinion of the Court

here, that counsel had adequately performed at the pen­
alty phase of trial.
                              2
   The Court of Appeals held that the California Supreme
Court had unreasonably applied Strickland because Pin­
holster’s attorneys “w[ere] far more deficient than . . . the
attorneys in Terry Williams, Wiggins [v. Smith, 539 U. S.
510 (2003)], and Rompilla [v. Beard, 545 U. S. 374 (2005)],
where in each case the Supreme Court upheld the peti­
tioner’s ineffective assistance claim.” 590 F. 3d, at 671.
The court drew from those cases a “constitutional duty to
investigate,” id., at 674, and the principle that “[i]t is
prima facie ineffective assistance for counsel to ‘abandon[ ]
their investigation of [the] petitioner’s background after
having acquired only rudimentary knowledge of his his­
tory from a narrow set of sources,’ ” ibid. (quoting Wiggins
v. Smith, 539 U. S. 510, 524–525 (2003)). The court ex­
plained that it could not “lightly disregard” a failure to
introduce evidence of “excruciating life history” or “night­
marish childhood.” 590 F. 3d, at 684 (internal quotation
marks omitted).
   The Court of Appeals misapplied Strickland and over­
looked “the constitutionally protected independence of
counsel and . . . the wide latitude counsel must have in
making tactical decisions.” 466 U. S., at 689. Beyond the
general requirement of reasonableness, “specific guide­
lines are not appropriate.” Id., at 688. “No particular set
of detailed rules for counsel’s conduct can satisfactorily
take account of the variety of circumstances faced by
defense counsel or the range of legitimate decisions . . . .”
Id., at 688–689. Strickland itself rejected the notion that
the same investigation will be required in every case. Id.,
at 691 (“[C]ounsel has a duty to make reasonable investi­
gations or to make a reasonable decision that makes par­
ticular investigations unnecessary” (emphasis added)). It
24                   CULLEN v. PINHOLSTER

                         Opinion of the Court

is “[r]are” that constitutionally competent representation
will require “any one technique or approach.” Richter, 562
U. S., at ___ (slip op., at 17). The Court of Appeals erred
in attributing strict rules to this Court’s recent case law.17
   Nor did the Court of Appeals properly apply the strong
presumption of competence that Strickland mandates.
The court dismissed the dissent’s application of the pre­
sumption as “fabricat[ing] an excuse that the attorneys
themselves could not conjure up.” 590 F. 3d, at 673. But
Strickland specifically commands that a court “must
indulge [the] strong presumption” that counsel “made all
significant decisions in the exercise of reasonable profes­
sional judgment.” 466 U. S., at 689–690. The Court of
Appeals was required not simply to “give [the] attorneys
the benefit of the doubt,” 590 F. 3d, at 673, but to affirma­
tively entertain the range of possible “reasons Pinholster’s
counsel may have had for proceeding as they did,” id., at
692 (Kozinski, C. J., dissenting). See also Richter, supra,
at ___ (slip op., at 20) (“Strickland . . . calls for an inquiry
into the objective reasonableness of counsel’s performance,
not counsel’s subjective state of mind”).
   JUSTICE SOTOMAYOR questions whether it would have
been a reasonable professional judgment for Pinholster’s
trial counsel to adopt a family-sympathy mitigation de­
fense. Post, at 27. She cites no evidence, however, that
such an approach would have been inconsistent with the
standard of professional competence in capital cases that
prevailed in Los Angeles in 1984. Indeed, she does not
contest that, at the time, the defense bar in California had
been using that strategy. See supra, at 19; post, at 28,
n. 21. JUSTICE SOTOMAYOR relies heavily on Wiggins, but
——————
  17 The Court of Appeals was not necessarily wrong in looking to other

precedents of this Court for guidance, but “the Strickland test ‘of
necessity requires a case-by-case examination of the evidence.’ ” Terry
Williams, 529 U. S. 362, 391 (2000) (quoting Wright v. West, 505 U. S.
277, 308 (1992) (KENNEDY, J., concurring in judgment)).
                 Cite as: 563 U. S. ____ (2011)           25

                     Opinion of the Court

in that case the defendant’s trial counsel specifically ac­
knowledged a standard practice for capital cases in Mary­
land that was inconsistent with what he had done. 539
U. S., at 524.
   At bottom, JUSTICE SOTOMAYOR’s view is grounded in
little more than her own sense of “prudence,” post, at 26
(internal quotation marks omitted), and what appears to
be her belief that the only reasonable mitigation strategy
in capital cases is to “help” the jury “understand” the
defendant, post, at 35. According to JUSTICE SOTOMAYOR,
that Pinholster was an unsympathetic client “com­
pound[ed], rather than excuse[d], counsel’s deficiency” in
pursuing further evidence “that could explain why Pinhol­
ster was the way he was.” Post, at 30. But it certainly can
be reasonable for attorneys to conclude that creating
sympathy for the defendant’s family is a better idea be­
cause the defendant himself is simply unsympathetic.
   JUSTICE SOTOMAYOR’s approach is flatly inconsistent
with Strickland’s recognition that “[t]here are countless
ways to provide effective assistance in any given case.”
466 U. S., at 689. There comes a point where a defense
attorney will reasonably decide that another strategy is in
order, thus “mak[ing] particular investigations unneces­
sary.” Id., at 691; cf. 590 F. 3d, at 692 (Kozinski, C. J.,
dissenting) (“The current infatuation with ‘humanizing’
the defendant as the be-all and end-all of mitigation disre­
gards the possibility that this may be the wrong tactic in
some cases because experienced lawyers conclude that the
jury simply won’t buy it”). Those decisions are due “a
heavy measure of deference.” Strickland, supra, at 691.
The California Supreme Court could have reasonably
concluded that Pinholster’s counsel made such a reasoned
decision in this case.
   We have recently reiterated that “ ‘[s]urmounting Strick
land’s high bar is never an easy task.’ ” Richter, supra, at
___ (slip op., at 15) (quoting Padilla v. Kentucky, 559 U. S.
26                CULLEN v. PINHOLSTER

                     Opinion of the Court

___, ___ (2010) (slip op., at 14)). The Strickland standard
must be applied with “scrupulous care.” Richter, supra, at
___ (slip op., at 15). The Court of Appeals did not do so
here.
                              D
  Even if his trial counsel had performed deficiently,
Pinholster also has failed to show that the California
Supreme Court must have unreasonably concluded that
Pinholster was not prejudiced. “[T]he question is whether
there is a reasonable probability that, absent the errors,
the sentencer . . . would have concluded that the balance of
aggravating and mitigating circumstances did not warrant
death.” Strickland, supra, at 695. We therefore “reweigh
the evidence in aggravation against the totality of avail­
able mitigating evidence.” Wiggins, supra, at 534.
                             1
  We turn first to the aggravating and mitigating evi­
dence that the sentencing jury considered. See Strickland,
supra, at 695 (“[A] court hearing an ineffectiveness claim
must consider the totality of the evidence before the judge
or jury”). Here, the same jury heard both the guilt and
penalty phases and was instructed to consider all the
evidence presented. Cf. Visciotti, 537 U. S., at 25 (noting
that the state habeas court had correctly considered miti­
gating evidence introduced during the guilt phase).
  The State presented extensive aggravating evidence. As
we have already discussed, the jury watched Pinholster
revel in his extensive criminal history. Supra, at 21.
Then, during the penalty phase, the State presented evi­
dence that Pinholster had threatened to kill the State’s
lead witness, assaulted a man with a straight razor, and
kidnaped another person with a knife. The State showed
that Pinholster had a history of violent outbursts, includ­
ing striking and threatening a bailiff after a court proceed­
                      Cite as: 563 U. S. ____ (2011)                     27

                           Opinion of the Court

ing at age 17, breaking his wife’s jaw,18 resisting arrest by
faking seizures, and assaulting and spitting on police
officers. The jury also heard about Pinholster’s involve­
ment in juvenile gangs and his substantial disciplinary
record in both county and state jails, where he had threat­
ened, assaulted, and thrown urine at guards, and fought
with other inmates. While in jail, Pinholster had been
segregated for a time due to his propensity for violence
and placed on a “special disciplinary diet” reserved only
for the most disruptive inmates. 52 Tr. 7305.
   The mitigating evidence consisted primarily of the
penalty-phase testimony of Pinholster’s mother, Brashear,
who gave a detailed account of Pinholster’s troubled child­
hood and adolescence. Early childhood was quite difficult.
The family “didn’t have lots of money.” Id., at 7404.
When he was very young, Pinholster suffered two serious
head injuries, first at age 2 or 3 when he was run over by a
car, and again at age 4 or 5 when he went through the
windshield during a car accident. When he was 5, Pinhol­
ster’s stepfather moved in and was abusive, or nearly so.
   Pinholster always struggled in school. He was disrup­
tive in kindergarten and was failing by first grade. He got
in fights and would run out of the classroom. In third
grade, Pinholster’s teacher suggested that he was more
than just a “ ‘disruptive child.’ ” Id., at 7394. Following
tests at a clinic, Pinholster was sent to a school for educa­
tionally handicapped children where his performance
improved.
   At age 10, psychiatrists recommended that Pinholster
be sent to a mental institution, although he did not go.
Pinholster had continued to initiate fights with his broth­
ers and to act like “Robin Hood” around the neighborhood,
——————
  18 Pinholster’s wife waived her spousal privilege to testify to this fact.

She acknowledged that her testimony would be used to argue that her
husband should be executed.
28                   CULLEN v. PINHOLSTER

                         Opinion of the Court

“[s]tealing from the rich and giving to the poor.” Id., at
7395. Brashear had thought then that “[s]omething was
not working right.” Id., at 7396.
   By age 10 or 11, Pinholster was living in boy’s homes
and juvenile halls. He spent six months when he was 12
in a state mental institution for emotionally handicapped
children. By the time he was 18, Pinholster was in county
jail, where he was beaten badly. Brashear suspected that
the beating caused Pinholster’s epilepsy, for which he has
been prescribed medication. After a stint in state prison,
Pinholster returned home but acted “unusual” and had
trouble readjusting to life. Id., at 7405.
   Pinholster’s siblings were “basically very good children,”
although they would get into trouble. Id., at 7401. His
brother, Terry, had been arrested for drunk driving and
his sister, Tammy, for public intoxication. Tammy also
was arrested for drug possession and was self-destructive
and “wild.” Ibid. Pinholster’s eldest brother, Alvin, died a
fugitive from California authorities.19
   In addition to Brashear’s penalty-phase testimony,
Pinholster had previously presented mitigating evidence
during the guilt phase from his brother, Terry. Terry
testified that Pinholster was “more or less in institutions
all his life,” suffered from epilepsy, and was “more or less”
drunk on the night of the murders. 42 id., at 6015, 6036.
   After considering this aggravating and mitigating evi­
dence, the jury returned a sentence of death. The state

——————
  19 JUSTICE SOTOMAYOR criticizes Brashear’s testimony as “self­

interested,” post, at 31, but the whole premise of the family-sympathy
defense is the family’s interest. She similarly makes much of the fact
that the prosecutor “belittle[d]” Brashear’s testimony in closing argu­
ment. Post, at 33. We fail to see the point. Any diligent prosecutor
would have challenged whatever mitigating evidence the defense had
put on. And, we would certainly not expect the prosecutor’s closing
argument to have described the evidence in the light most favorable to
Pinholster. But see ibid., n. 26.
                 Cite as: 563 U. S. ____ (2011)           29

                     Opinion of the Court

trial court found that the jury’s determination was “sup­
ported overwhelmingly by the weight of the evidence” and
added that “the factors in aggravation beyond all reason­
able doubt outweigh those in mitigation.” Clerk’s Tr.
1184, 1186.
                               2
   There is no reasonable probability that the additional
evidence Pinholster presented in his state habeas proceed­
ings would have changed the jury’s verdict. The “new”
evidence largely duplicated the mitigation evidence at
trial. School and medical records basically substantiate
the testimony of Pinholster’s mother and brother. Decla­
rations from Pinholster’s siblings support his mother’s
testimony that his stepfather was abusive and explain
that Pinholster was beaten with fists, belts, and even
wooden boards.
   To the extent the state habeas record includes new
factual allegations or evidence, much of it is of question­
able mitigating value. If Pinholster had called Dr. Woods
to testify consistently with his psychiatric report, Pinhol­
ster would have opened the door to rebuttal by a state
expert. See, e.g., Wong v. Belmontes, 558 U. S. ___, ___
(2009) (per curiam) (slip op., at 10–12) (taking into account
that certain mitigating evidence would have exposed the
petitioner to further aggravating evidence). The new
evidence relating to Pinholster’s family⎯their more seri­
ous substance abuse, mental illness, and criminal prob­
lems, see post, at 22⎯is also by no means clearly mitigat­
ing, as the jury might have concluded that Pinholster was
simply beyond rehabilitation. Cf. Atkins v. Virginia, 536
U. S. 304, 321 (2002) (recognizing that mitigating evidence
can be a “two-edged sword” that juries might find to show
future dangerousness).
   The remaining new material in the state habeas record
is sparse. We learn that Pinholster’s brother Alvin died of
30                  CULLEN v. PINHOLSTER

                       Opinion of the Court

suicide by drug overdose, and there are passing references
to Pinholster’s own drug dependency. According to Dr.
Stalberg, Pinholster’s “school records” apparently evi­
denced “some degree” of brain damage. App. to Brief in
Opposition 219. Mostly, there are just a few new details
about Pinholster’s childhood.       Pinholster apparently
looked like his biological father, whom his grandparents
“loathed.” Pet. for Writ of Habeas Corpus in No. S004616
(Cal.), Exh. 98, p. 1. Accordingly, whenever his grandpar­
ents “spanked or disciplined” the kids, Pinholster “always
got the worst of it.” Ibid. Pinholster was mostly unsuper­
vised and “didn’t get much love,” because his mother and
stepfather were always working and “were more concerned
with their own lives than the welfare of their kids.” Id., at
2. Neither parent seemed concerned about Pinholster’s
schooling. Finally, Pinholster’s aunt once saw the children
mixing flour and water to make something to eat, al­
though “[m]ost meals consisted of canned spaghetti and
foods of that ilk.” Id., at 1.
   Given what little additional mitigating evidence Pinhol­
ster presented in state habeas, we cannot say that the
California Supreme Court’s determination was unreason­
able. Having already heard much of what is included in
the state habeas record, the jury returned a sentence of
death. Moreover, some of the new testimony would likely
have undercut the mitigating value of the testimony by
Pinholster’s mother. The new material is thus not so
significant that, even assuming Pinholster’s trial counsel
performed deficiently, it was necessarily unreasonable for
the California Supreme Court to conclude that Pinholster
had failed to show a “substantial” likelihood of a different
sentence. Richter, 562 U. S., at ___ (slip op., at 22) (citing
Strickland, 466 U. S., at 693).
                               3
     As with deficiency, the Court of Appeals found this case
                    Cite as: 563 U. S. ____ (2011)                  31

                         Opinion of the Court

to be “materially indistinguishable” from Terry Williams
and Rompilla v. Beard, 545 U. S. 374 (2005). 590 F. 3d, at
684. But this Court did not apply AEDPA deference to the
question of prejudice in those cases; each of them lack the
important “doubly deferential” standard of Strickland and
AEDPA. See Terry Williams, 529 U. S., at 395–397 (re­
viewing a state-court decision that did not apply the cor­
rect legal standard); Rompilla, supra, at 390 (reviewing
Strickland prejudice de novo because the state-court deci­
sion did not reach the question). Those cases therefore
offer no guidance with respect to whether a state court has
unreasonably determined that prejudice is lacking. We
have said time and again that “an unreasonable applica­
tion of federal law is different from an incorrect applica­
tion of federal law.” Richter, supra, at ___ (slip op., at 11)
(internal quotation marks omitted). Even if the Court of
Appeals might have reached a different conclusion as an
initial matter, it was not an unreasonable application of
our precedent for the California Supreme Court to con­
clude that Pinholster did not establish prejudice.20
                        *    *  *
  The judgment of the United States Court of Appeals for
the Ninth Circuit is reversed.
                                        It is so ordered.

——————
  20 Because Pinholster has failed to demonstrate that the adjudication
of his claim based on the state-court record resulted in a decision
“contrary to” or “involv[ing] an unreasonable application” of federal
law, a writ of habeas corpus “shall not be granted” and our analysis is
at an end. 28 U. S. C. §2254(d). We are barred from considering the
evidence Pinholster submitted in the District Court that he contends
additionally supports his claim. For that reason, we need not decide
whether §2254(e)(2) prohibited the District Court from holding the
evidentiary hearing or whether a district court may ever choose to hold
an evidentiary hearing before it determines that §2254(d) has been
satisfied.
                 Cite as: 563 U. S. ____ (2011)           1

                     ALITO, J., concurring

SUPREME COURT OF THE UNITED STATES
                         _________________

                         No. 09–1088
                         _________________


VINCENT CULLEN, ACTING WARDEN, PETITIONER
         v. SCOTT LYNN PINHOLSTER
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

            APPEALS FOR THE NINTH CIRCUIT

                        [April 4, 2011]


  JUSTICE ALITO, concurring in part and concurring in the
judgment.
  Although I concur in the Court’s judgment, I agree with
the conclusion reached in Part I of the dissent, namely,
that, when an evidentiary hearing is properly held in
federal court, review under 28 U. S. C. §2254(d)(1) must
take into account the evidence admitted at that hearing.
As the dissent points out, refusing to consider the evidence
received in the hearing in federal court gives §2254(e)(2)
an implausibly narrow scope and will lead either to results
that Congress surely did not intend or to the distortion of
other provisions of the Antiterrorism and Effective Death
Penalty Act of 1996 (AEDPA), 110 Stat. 1214, and the law
on “cause and prejudice.” See post, at 9–12 (opinion of
SOTOMAYOR, J.).
  Under AEDPA evidentiary hearings in federal court
should be rare. The petitioner generally must have made
a diligent effort to produce in state court the new evidence
on which he seeks to rely. See §2254(e)(2); Williams v.
Taylor, 529 U. S. 420, 433–434 (2000). If that requirement
is not satisfied, the petitioner may establish the factual
predicate for a claim in a federal-court hearing only if,
among other things, “the facts underlying the claim would
be sufficient to establish by clear and convincing evidence
that but for constitutional error, no reasonable factfinder
2                 CULLEN v. PINHOLSTER

                      Opinion of ALITO, J.

would have found the applicant guilty of the underlying
offense.” §2254(e)(2)(B).
   Even when the petitioner does satisfy the diligence
standard adopted in Williams v. Taylor, supra, a hearing
should not be held in federal court unless the new evi
dence that the petitioner seeks to introduce was not and
could not have been offered in the state-court proceeding.
Section 2254(e)(2) bars a hearing in certain situations, but
it does not mean that a hearing is allowed in all other
situations. See Schriro v. Landrigan, 550 U. S. 465, 473–
474 (2007). The whole thrust of AEDPA is essentially to
reserve federal habeas relief for those cases in which the
state courts acted unreasonably. See §§2254(d)(1), (2),
(e)(1). Permitting a petitioner to obtain federal habeas
relief on the basis of evidence that could have been but
was not offered in state court would upset this scheme.
   In this case, for essentially the reasons set out in the
dissent from the Court of Appeals’ en banc decision, see
Pinholster v. Ayers, 590 F. 3d 651, 688–691 (CA9 2009)
(opinion of Kozinski, J.), I would hold that the federal
court hearing should not have been held because respon
dent did not diligently present his new evidence to the
California courts. And I join all but Part II of the opinion
of the Court, as I agree that the decision of the state court
represented a reasonable application of clearly established
Supreme Court precedent in light of the state-court record.
                  Cite as: 563 U. S. ____ (2011)             1

                      Opinion of BREYER, J.

SUPREME COURT OF THE UNITED STATES
                          _________________

                          No. 09–1088
                          _________________


VINCENT CULLEN, ACTING WARDEN, PETITIONER
         v. SCOTT LYNN PINHOLSTER
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

            APPEALS FOR THE NINTH CIRCUIT

                         [April 4, 2011]


   JUSTICE BREYER, concurring in part and dissenting in
part.
   I join Parts I and II of the Court’s opinion. I do not join
Part III, for I would send this case back to the Court of
Appeals so that it can apply the legal standards that Part
II announces to the complex facts of this case. Compare
ante, at 14–31 (majority opinion), with post, at 17–42
(SOTOMAYOR, J., dissenting).
   Like the Court, I believe that its understanding of
28 U. S. C. §2254(d)(1) does not leave AEDPA’s hearing
section, §2254(e), without work to do. An offender who
believes he is entitled to habeas relief must first present a
claim (including his evidence) to the state courts. If the
state courts reject the claim, then a federal habeas court
may review that rejection on the basis of the materials
considered by the state court. If the federal habeas court
finds that the state-court decision fails (d)’s test (or if (d)
does not apply), then an (e) hearing may be needed.
   For example, if the state-court rejection assumed the
habeas petitioner’s facts (deciding that, even if those facts
were true, federal law was not violated), then (after find
ing the state court wrong on a (d) ground) an (e) hearing
might be needed to determine whether the facts alleged
were indeed true. Or if the state-court rejection rested on
a state ground, which a federal habeas court found inade
2                  CULLEN v. PINHOLSTER

                     Opinion of BREYER, J.

quate, then an (e) hearing might be needed to consider the
petitioner’s (now unblocked) substantive federal claim. Or
if the state-court rejection rested on only one of several
related federal grounds (e.g., that counsel’s assistance was
not “inadequate”), then, if the federal court found that the
state court’s decision in respect to the ground it decided
violated (d), an (e) hearing might be needed to consider
other related parts of the whole constitutional claim (e.g.,
whether the counsel’s “inadequate” assistance was also
prejudicial). There may be other situations in which an (e)
hearing is needed as well.
   In this case, however, we cannot say whether an (e)
hearing is needed until we know whether the state court,
in rejecting Pinholster’s claim on the basis presented to
that state court, violated (d). (In my view, the lower
courts’ analysis in respect to this matter is inadequate.)
   There is no role in (d) analysis for a habeas petitioner to
introduce evidence that was not first presented to the
state courts. But that does not mean that Pinholster is
without recourse to present new evidence. He can always
return to state court presenting new evidence not previ
ously presented. If the state court again denies relief, he
might be able to return to federal court to make claims
related to the latest rejection, subject to AEDPA’s limita
tions on successive petitions. See §2244.
   I am not trying to predict the future course of these
proceedings. I point out only that, in my view, AEDPA is
not designed to take necessary remedies from a habeas
petitioner but to give the State a first opportunity to con
sider most matters and to insist that federal courts prop
erly respect state-court determinations.
                 Cite as: 563 U. S. ____ (2011)           1

                   SOTOMAYOR, J., dissenting

SUPREME COURT OF THE UNITED STATES
                         _________________

                         No. 09–1088
                         _________________


VINCENT CULLEN, ACTING WARDEN, PETITIONER
         v. SCOTT LYNN PINHOLSTER
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

            APPEALS FOR THE NINTH CIRCUIT

                        [April 4, 2011]


   JUSTICE SOTOMAYOR, with whom JUSTICE GINSBURG
and JUSTICE KAGAN join as to Part II, dissenting.
   Some habeas petitioners are unable to develop the fac
tual basis of their claims in state court through no fault
of their own. Congress recognized as much when it en
acted the Antiterrorism and Effective Death Penalty Act of
1996 (AEDPA), 110 Stat. 1214, and permitted therein the
introduction of new evidence in federal habeas proceed
ings in certain limited circumstances. See 28 U. S. C.
§2254(e)(2). Under the Court’s novel interpretation of
§2254(d)(1), however, federal courts must turn a blind eye
to new evidence in deciding whether a petitioner has
satisfied §2254(d)(1)’s threshold obstacle to federal habeas
relief—even when it is clear that the petitioner would be
entitled to relief in light of that evidence. In reading
the statute to “compe[l]” this harsh result, ante, at 9,
the Court ignores a key textual difference between
§§2254(d)(1) and 2254(d)(2) and discards the previous
understanding in our precedents that new evidence can, in
fact, inform the §2254(d)(1) inquiry. I therefore dissent
from the Court’s first holding.
   I also disagree with the Court that, even if the
§2254(d)(1) analysis is limited to the state-court record,
respondent Scott Pinholster failed to demonstrate that the
California Supreme Court’s decision denying his ineffec
2                 CULLEN v. PINHOLSTER

                   SOTOMAYOR, J., dissenting

tive-assistance-of-counsel claim was an unreasonable
application of Strickland v. Washington, 466 U. S. 668
(1984). There is no reason for the majority to decide
whether the §2254(d)(1) analysis is limited to the state
court record because Pinholster satisfied §2254(d)(1) on
either the state- or federal-court record.
                             I
  The Court first holds that, in determining whether a
state-court decision is an unreasonable application of
Supreme Court precedent under §2254(d)(1), “review . . . is
limited to the record that was before the state court that
adjudicated the claim on the merits.” Ante, at 9. New
evidence adduced at a federal evidentiary hearing is
now irrelevant to determining whether a petitioner has
satisfied §2254(d)(1). This holding is unnecessary to pro
mote AEDPA’s purposes, and it is inconsistent with the
provision’s text, the structure of the statute, and our
precedents.
                              A
   To understand the significance of the majority’s holding,
it is important to view the issue in context. AEDPA’s
entire structure—which gives state courts the opportunity
to decide factual and legal questions in the first instance—
ensures that evidentiary hearings in federal habeas pro
ceedings are very rare. See N. King, F. Cheesman, & B.
Ostrom, Final Technical Report: Habeas Litigation in
U. S. District Courts 35–36 (2007) (evidentiary hearings
under AEDPA occur in 0.4 percent of noncapital cases and
9.5 percent of capital cases). Even absent the new restric
tion created by today’s holding, AEDPA erects multiple
hurdles to a state prisoner’s ability to introduce new evi
dence in a federal habeas proceeding.
   First, “[u]nder the exhaustion requirement, a habeas
petitioner challenging a state conviction must first at
                    Cite as: 563 U. S. ____ (2011)                 3

                      SOTOMAYOR, J., dissenting

tempt to present his claim in state court.” Harrington v.
Richter, 562 U. S. ___, ___ (2011) (slip op., at 13); see also
§2254(b)(1)(A). With certain narrow exceptions, federal
courts cannot consider a claim at all, let alone accept new
evidence relevant to the claim, if it has not been exhausted
in state court.1 The exhaustion requirement thus reserves
to state courts the first opportunity to resolve factual
disputes relevant to a state prisoner’s claim.            See
O’Sullivan v. Boerckel, 526 U. S. 838, 845 (1999).
  Second, the exhaustion requirement is “complement[ed]”
by the standards set forth in §2254(d). Harrington, 562
U. S., at ___ (slip op., at 14). Under this provision, a fed
eral court may not grant habeas relief on any “claim that
was adjudicated on the merits in State court proceedings”
unless the adjudication
        “(1) resulted in a decision that was contrary to, or
     involved an unreasonable application of, clearly estab
     lished Federal law, as determined by the Supreme
     Court of the United States; or
        “(2) resulted in a decision that was based on an un
     reasonable determination of the facts in light of the
     evidence presented in the State court proceeding.”
These standards “control whether to grant habeas relief.”
Schriro v. Landrigan, 550 U. S. 465, 474 (2007). Accord
ingly, we have said, if the factual allegations a petitioner
seeks to prove at an evidentiary hearing would not satisfy
these standards, there is no reason for a hearing. See id.,
at 481. In such a case, the district court may exercise its
“discretion to deny an evidentiary hearing.” Ibid.; see also
infra, at 13–14. This approach makes eminent sense: If
district courts held evidentiary hearings without first
——————
  1 Relatedly,a state prisoner must, as a general matter, properly ex
haust his federal claims in state court to avoid having his claim de
faulted on procedural grounds. See Coleman v. Thompson, 501 U. S.
722, 750 (1991).
4                     CULLEN v. PINHOLSTER

                       SOTOMAYOR, J., dissenting

asking whether the evidence the petitioner seeks to pre
sent would satisfy AEDPA’s demanding standards, they
would needlessly prolong federal habeas proceedings.
  Third, even when a petitioner seeks to introduce new
evidence that would entitle him to relief, AEDPA prohibits
him from doing so, except in a narrow range of cases,
unless he “made a reasonable attempt, in light of the
information available at the time, to investigate and pur
sue claims in state court.” Williams v. Taylor, 529 U. S.
420, 435 (2000) (Michael Williams). Thus, §2254(e)(2)
provides:
     “If the applicant has failed to develop the factual basis
     of a claim in State court proceedings, the court shall
     not hold an evidentiary hearing on the claim unless
     the applicant shows that—
        “(A) the claim relies on—
        “(i) a new rule of constitutional law, made retroac
     tive to cases on collateral review by the Supreme
     Court, that was previously unavailable; or
        “(ii) a factual predicate that could not have been
     previously discovered through the exercise of due dili
     gence; and
        “(B) the facts underlying the claim would be suffi
     cient to establish by clear and convincing evidence
     that but for constitutional error, no reasonable fact
     finder would have found the applicant guilty of the
     underlying offense.”
In Michael Williams, we construed the opening clause of
this provision—which triggers the bar on evidentiary
hearings—to apply when “there is lack of diligence, or
some greater fault, attributable to the prisoner or the
prisoner’s counsel.”2 Id., at 432. AEDPA thus bars an
——————
  2 Section 2254(e)(2) also governs an attempt to obtain relief “based on

new evidence without an evidentiary hearing.” Holland v. Jackson, 542
U. S. 649, 653 (2004) (per curiam) (emphasis deleted).
                        Cite as: 563 U. S. ____ (2011)     5

                          SOTOMAYOR, J., dissenting

evidentiary hearing for a nondiligent petitioner unless the
petitioner can satisfy both §§2254(e)(2)(A) and (B), which
few petitioners can. Section 2254(e)(2) in this way incen
tivizes state petitioners to develop the factual basis of
their claims in state court.
   To the limited extent that federal evidentiary hearings
are available under AEDPA, they ensure that petitioners
who diligently developed the factual basis of their claims
in state court, discovered new evidence after the state
court proceeding, and cannot return to state court retain
the ability to access the Great Writ. See ante, at 2 (ALITO,
J., concurring in part and concurring in judgment). “When
Congress codified new rules governing this previously
judicially managed area of law, it did so without losing
sight of the fact that the ‘writ of habeas corpus plays a
vital role in protecting constitutional rights.’ ” Holland v.
Florida, 560 U. S. ___, ___ (2010) (slip op., at 16) (quoting
Slack v. McDaniel, 529 U. S. 473, 483 (2000)). Allowing a
petitioner to introduce new evidence at a hearing in the
limited circumstance permitted by §2254(e)(2) does not
upset the balance that Congress struck in AEDPA be
tween the state and federal courts.           By construing
§2254(d)(1) to do the work of other provisions in AEDPA,
the majority has subverted Congress’ careful balance of
responsibilities. It has also created unnecessarily a brand
new set of procedural complexities that lower courts will
have to confront.3
                             B
  The majority’s interpretation of §2254(d)(1) finds no
support in the provision’s text or the statute’s structure as
a whole.
                          1
  Section 2254(d)(1) requires district courts to ask
——————
 3 See,   e.g., nn. 5, 7, and 13, infra.
6                  CULLEN v. PINHOLSTER

                   SOTOMAYOR, J., dissenting

whether a state-court adjudication on the merits “resulted
in a decision that was contrary to, or involved an unrea
sonable application of, clearly established Federal law, as
determined by the Supreme Court of the United States.”
Because this provision uses “backward-looking lan
guage”—i.e., past-tense verbs—the majority believes that
it limits review to the state-court record. Ante, at 9. But
both §§2254(d)(1) and 2254(d)(2) use “backward-looking
language,” and §2254(d)(2)—unlike §2254(d)(1)—expressly
directs district courts to base their review on “the evidence
presented in the State court proceeding.” If use of the past
tense were sufficient to indicate Congress’ intent to re
strict analysis to the state-court record, the phrase “in
light of the evidence presented in the State court proceed
ing” in §2254(d)(2) would be superfluous. The majority’s
construction of §2254(d)(1) fails to give meaning to Con
gress’ decision to include language referring to the evi
dence presented to the state court in §2254(d)(2). Cf.
Bates v. United States, 522 U. S. 23, 29–30 (1997) (“Where
Congress includes particular language in one section of a
statute but omits it in another section of the same Act, it
is generally presumed that Congress acts intentionally
and purposely in the disparate inclusion or exclusion”
(internal quotation marks and brackets omitted)).
   Ignoring our usual “reluctan[ce] to treat statutory terms
as surplusage in any setting,” TRW Inc. v. Andrews, 534
U. S. 19, 31 (2001) (internal quotation marks omitted), the
majority characterizes the phrase appearing in §2254(d)(2)
as mere “clarifying language,” ante, at 12, n. 7. It specu
lates that “[t]he omission of clarifying language from
§2254(d)(1) just as likely reflects Congress’ belief that such
language was unnecessary as it does anything else.” Ante,
at 12–13, n. 7. The argument that this phrase is merely
“clarifying” might have more force, however, had Congress
included this phrase in §2254(d)(1) but not in §2254(d)(2).
As between the two provisions, §2254(d)(2)—which re
                     Cite as: 563 U. S. ____ (2011)                     7

                       SOTOMAYOR, J., dissenting

quires review of the state court’s “determination of the
facts”—more logically depends on the facts presented to
the state court. Because this provision needs less clarifi
cation on this point than §2254(d)(1), it is all the more
telling that Congress included this phrase in §2254(d)(2)
but elected to exclude it from §2254(d)(1).
  Unlike my colleagues in the majority, I refuse to assume
that Congress simply engaged in sloppy drafting. The
inclusion of this phrase in §2254(d)(2)—coupled with its
omission     from     §2254(d)(2)’s   partner    provision,
§2254(d)(1)—provides strong reason to think that Con
gress did not intend for the §2254(d)(1) analysis to be
limited categorically to “the evidence presented in the
State court proceeding.”
                              2
  The “ ‘broader context of the statute as a whole,’ ” ante,
at 9 (quoting Robinson v. Shell Oil Co., 519 U. S. 337, 341
(1997)), reinforces this conclusion. In particular, Con
gress’ decision to include in AEDPA a provision,
§2254(e)(2), that permits federal evidentiary hearings in
certain circumstances provides further evidence that
Congress did not intend to limit the §2254(d)(1) inquiry to
the state-court record in every case.
  We have long recognized that some diligent habeas
petitioners are unable to develop all of the facts support
ing their claims in state court.4 As discussed above, in
——————
  4 See, e.g., Michael Williams, 529 U. S. 420, 432 (2000) (noting that

diligent efforts to develop the facts might be “thwarted, for example, by
the conduct of another or by happenstance”); id., at 434 (noting that the
prosecution might have “concealed the facts” supporting “a claim which
was pursued with diligence”); Townsend v. Sain, 372 U. S. 293, 313
(1963) (requiring federal courts to grant evidentiary hearings when,
inter alia, “the fact-finding procedure employed by the state court was
not adequate to afford a full and fair hearing” or “there is a substantial
allegation of newly discovered evidence”), overruled in part on other
grounds by Keeney v. Tamayo-Reyes, 504 U. S. 1, 5 (1992).
8                      CULLEN v. PINHOLSTER

                       SOTOMAYOR, J., dissenting

enacting AEDPA, Congress generally barred evidentiary
hearings for petitioners who did not “exercise diligence in
pursuing their claims” in state court. Michael Williams,
529 U. S., at 436; see also §2254(e)(2). Importantly, it did
not impose any express limit on evidentiary hearings for
petitioners who had been diligent in state court. See id.,
at 436 (“[T]he statute does not equate prisoners who exer
cise diligence in pursuing their claims with those who do
not”). For those petitioners, Congress left the decision to
hold a hearing “to the sound discretion of district courts.”
Landrigan, 550 U. S., at 473.
   Faced with situations in which a diligent petitioner
offers additional evidence in federal court, the courts of
appeals have taken two approaches to applying
§2254(d)(1). Some courts have held that when a federal
court admits new evidence supporting a claim adjudicated
on the merits in state court, §2254(d)(1) does not apply at
all and the federal court may review the claim de novo.
See ante, at 12; Holland v. Jackson, 542 U. S. 649, 653
(2004) (per curiam); see, e.g., Winston v. Kelly, 592 F. 3d
535, 555–556 (CA4 2010). I agree with the majority’s
rejection of this approach. See ante, at 12. It would un
dermine the comity principles motivating AEDPA to de
cline to defer to a state-court adjudication of a claim
because the state court, through no fault of its own,
lacked all the relevant evidence.5
——————
    5 Of
       course, §2254(d)(1) only applies when a state court has adjudi
cated a claim on the merits. There may be situations in which new
evidence supporting a claim adjudicated on the merits gives rise to an
altogether different claim. See, e.g., Reply Brief for Petitioner 10–11
(evidence withheld by the prosecutor relating to one claim may give rise
to a separate claim under Brady v. Maryland, 373 U. S. 83 (1963)). The
majority opinion does not foreclose this possibility.
  I assume that the majority does not intend to suggest that review is
limited to the state-court record when a petitioner’s inability to develop
the facts supporting his claim was the fault of the state court itself. See
generally Tr. of Oral Arg. in Bell v. Kelly, O. T. 2008, No. 07–1223.
                 Cite as: 563 U. S. ____ (2011)            9

                   SOTOMAYOR, J., dissenting

  Other courts of appeals, including the court below, have
struck a more considered balance. These courts have held
that §2254(d)(1) continues to apply but that new evidence
properly presented in a federal hearing is relevant to the
reasonableness of the state-court decision. See Pinholster
v. Ayers, 590 F. 3d 651, 668 (CA9 2009) (en banc) (“If the
evidence is admissible under Michael Williams or
§2254(e)(2), and if it does not render the petitioner’s
claims unexhausted . . . , then it is properly considered in
evaluating whether the legal conclusion reached by the
state habeas court was a reasonable application of Su
preme Court law”); accord, Wilson v. Mazzuca, 570 F. 3d
490, 500 (CA2 2009); Pecoraro v. Walls, 286 F. 3d 439, 443
(CA7 2002); Valdez v. Cockrell, 274 F. 3d 941, 952 (CA5
2001). This approach accommodates the competing goals,
reflected in §§2254(d) and 2254(e)(2), of according defer
ence to reasonable state-court decisions and preserving
the opportunity for diligent petitioners to present evidence
to the federal court when they were unable to do so in
state court.
  The majority charts a third, novel course that, so far as I
am aware, no court of appeals has adopted: §2254(d)(1)
continues to apply when a petitioner has additional evi
dence that he was unable to present to the state court, but
the district court cannot consider that evidence in deciding
whether the petitioner has satisfied §2254(d)(1). The
problem with this approach is its potential to bar federal
habeas relief for diligent habeas petitioners who cannot
present new evidence to a state court.
   Consider, for example, a petitioner who diligently at
tempted in state court to develop the factual basis of a
claim that prosecutors withheld exculpatory witness
statements in violation of Brady v. Maryland, 373 U. S. 83
(1963). The state court denied relief on the ground that
the withheld evidence then known did not rise to the level
of materiality required under Brady. Before the time for
10                   CULLEN v. PINHOLSTER

                      SOTOMAYOR, J., dissenting

filing a federal habeas petition has expired, however, a
state court orders the State to disclose additional docu
ments the petitioner had timely requested under the
State’s public records Act. The disclosed documents reveal
that the State withheld other exculpatory witness state
ments, but state law would not permit the petitioner to
present the new evidence in a successive petition.6
   Under our precedent, if the petitioner had not presented
his Brady claim to the state court at all, his claim would
be deemed defaulted and the petitioner could attempt to
show cause and prejudice to overcome the default. See
Michael Williams, 529 U. S., at 444; see also n. 1, supra.
If, however, the new evidence merely bolsters a Brady
claim that was adjudicated on the merits in state court, it
is unclear how the petitioner can obtain federal habeas
relief after today’s holding. What may have been a rea
sonable decision on the state-court record may no longer
be reasonable in light of the new evidence. See Kyles v.
Whitley, 514 U. S. 419, 436 (1995) (materiality of Brady
evidence is viewed “collectively, not item by item”). Be
cause the state court adjudicated the petitioner’s Brady
claim on the merits, §2254(d)(1) would still apply. Yet,
under the majority’s interpretation of §2254(d)(1), a fed
eral court is now prohibited from considering the new
evidence in determining the reasonableness of the state
court decision.
   The majority’s interpretation of §2254(d)(1) thus sug
gests the anomalous result that petitioners with new
claims based on newly obtained evidence can obtain fed
eral habeas relief if they can show cause and prejudice for
their default but petitioners with newly obtained evidence
supporting a claim adjudicated on the merits in state court
——————
  6 See, e.g., id., at 37–38 (statement by counsel for the respondent

warden that Virginia law bars all successive habeas applications, even
in cases where the petitioner has new evidence).
                     Cite as: 563 U. S. ____ (2011)                   11

                       SOTOMAYOR, J., dissenting

cannot obtain federal habeas relief if they cannot first
satisfy §2254(d)(1) without the new evidence. That the
majority’s interpretation leads to this anomaly is good
reason to conclude that its interpretation is wrong. See
Keeney v. Tamayo-Reyes, 504 U. S. 1, 7–8 (1992) (“[I]t is
. . . irrational to distinguish between failing to properly
assert a federal claim in state court and failing in state
court to properly develop such a claim”).
    The majority responds to this anomaly by suggesting
that my hypothetical petitioner “may well [have] a new
claim.”7 Ante, at 14, n. 10. This suggestion is puzzling.
New evidence does not usually give rise to a new claim; it
merely provides additional proof of a claim already adjudi
cated on the merits.8 The majority presumably means
to suggest that the petitioner might be able to obtain
federal-court review of his new evidence if he can show
cause and prejudice for his failure to present the “new”
claim to a state court. In that scenario, however, the
federal court would review the purportedly “new” claim de
novo. The majority’s approach thus threatens to replace
deferential review of new evidence under §2254(d)(1) with
de novo review of new evidence in the form of “new”
claims.9 Because it is unlikely that Congress intended
de novo review—the result suggested by the majority’s
opinion—it must have intended for district courts to
consider newly discovered evidence in conducting the
§2254(d)(1) analysis.
——————
  7 The majority declines, however, to provide any guidance to the lower

courts on how to distinguish claims adjudicated on the merits from new
claims.
  8 Even if it can fairly be argued that my hypothetical petitioner has a

new claim, the majority fails to explain how a diligent petitioner with
new evidence supporting an existing claim can present his new evi
dence to a federal court.
  9 In this vein, it is the majority’s approach that “would not take seri

ously AEDPA’s requirement that federal courts defer to state-court
decisions.” Ante, at 10, n. 3.
12                    CULLEN v. PINHOLSTER

                       SOTOMAYOR, J., dissenting

  The majority’s reading of §2254(d)(1) appears ultimately
to rest on its understanding that state courts must have
the first opportunity to adjudicate habeas petitioners’
claims. See ante, at 9–10 (“It would be contrary to
[AEDPA’s exhaustion requirement] to allow a petitioner to
overcome an adverse state-court decision with new evi
dence introduced in a federal habeas court and reviewed
by that court in the first instance effectively de novo”).10
JUSTICE BREYER takes the same position. See ante, at 2
(opinion concurring in part and dissenting in part)
(AEDPA is designed “to give the State a first opportunity
to consider most matters”). I fully agree that habeas
petitioners must attempt to present evidence to state
courts in the first instance, as does JUSTICE ALITO, see
ante, at 2. Where I disagree with the majority is in my
understanding that §2254(e)(2) already accomplishes this
result.    By reading §2254(d)(1) to do the work of
§2254(e)(2), the majority gives §2254(e)(2) an unnaturally
cramped reading. As a result, the majority either has
foreclosed habeas relief for diligent petitioners who,
through no fault of their own, were unable to present
exculpatory evidence to the state court that adjudicated
their claims or has created a new set of procedural com
plexities for the lower courts to navigate to ensure the
availability of the Great Writ for diligent petitioners.
                             3
  These considerations lead me to agree with the courts of
appeals that have concluded that a federal court should
assess the reasonableness of a state court’s application of
clearly established federal law under §2254(d)(1) in light
of evidence properly admitted in a federal evidentiary
hearing. There is nothing “strange” about this approach.
——————
  10 Under my reading of §2254(d)(1), of course, the district court would

review properly admitted new evidence through the deferential lens of
§2254(d)(1), not de novo.
                 Cite as: 563 U. S. ____ (2011)          13

                   SOTOMAYOR, J., dissenting

Ante, at 10. Under §2254(d)(1), federal courts routinely
engage in analysis that the state court itself might never
have conducted or did not conduct. For example, when a
state court summarily denies a claim without explanation,
as the California Supreme Court did here, district courts
must deny habeas relief pursuant to §2254(d)(1) so long as
“there is any reasonable argument” supporting the denial
of the petitioner’s claim. Harrington, 562 U. S., at ___
(slip op., at 16). We likewise ask whether a state-court
decision unreasonably applied clearly established federal
law when the state court issued a reasoned decision but
failed to cite federal law altogether. See Early v. Packer,
537 U. S. 3, 8 (2002) (per curiam). Determining whether a
state court could reasonably have denied a petitioner relief
in light of newly discovered evidence is not so different
than determining whether there is any reasonable basis
for a state court’s unreasoned decision.
   Admittedly, the text of §2254(d)(1), standing alone, does
not compel either reading of that provision. But constru
ing §2254(d)(1) to permit consideration of evidence prop
erly introduced in federal court best accords with the text
of §2254(d)(2) and AEDPA’s structure as a whole. By
interpreting §2254(d)(1) to prevent nondiligent petitioners
from gaming the system—the very purpose of
§2254(e)(2)—the majority potentially has put habeas relief
out of reach for diligent petitioners with meritorious
claims based on new evidence.
                            C
  The majority claims that its holding is “consistent” with
our case law. Ante, at 10. Quite the opposite is true: Our
cases reflect our previous understanding that evidence
properly admitted pursuant to §2254(e)(2) is relevant to
the §2254(d)(1) analysis.
  In Landrigan, JUSTICE THOMAS, the author of today’s
opinion, confirmed this understanding of the interplay
14                    CULLEN v. PINHOLSTER

                       SOTOMAYOR, J., dissenting

between §§2254(d)(1) and 2254(e)(2). As noted above, we
admonished district courts to consider whether a peti
tioner’s allegations, if proved true, would satisfy §2254(d)
in determining whether to grant a hearing. After high
lighting the deference owed to state courts under
§§2254(d) and 2254(e)(1), we stated:
     “In deciding whether to grant an evidentiary hearing,
     a federal court must consider whether such a hearing
     could enable an applicant to prove the petition’s fac
     tual allegations, which, if true, would entitle the
     applicant to federal habeas relief. Because the defer
     ential standards prescribed by §2254 control whether
     to grant habeas relief, a federal court must take into
     account those standards in deciding whether an evi
     dentiary hearing is appropriate.” 550 U. S., at 474 (ci
     tation omitted).
By instructing district courts to consider the §2254(d)
standards in deciding whether to grant a hearing, we must
have understood that the evidence admitted at a hearing
could be considered in the §2254(d)(1) analysis. See Brief
for American Civil Liberties Union as Amicus Curiae 9
(“The whole point of Landrigan’s admonition that the
court must decide whether to hold a hearing with an eye
on §2254(d)(1) is that some proffers of evidence will not
justify federal fact-finding in view of §2254(d)(1), but that
other proffers of proof will”).11
   In Michael Williams, the warden argued that
§2254(e)(2) bars an evidentiary hearing whenever a peti
tioner was unable to develop the factual record in state
court, “whether or not through his own fault or neglect.”
——————
  11 The majority overlooks this aspect of Landrigan. It quotes Landri

gan’s observation that “if the record refutes the applicant’s factual
allegations or otherwise precludes habeas relief, a district court is not
required to hold an evidentiary hearing,” 550 U. S., at 474, but that
statement has no bearing on the question decided by the Court today.
                    Cite as: 563 U. S. ____ (2011)                  15

                      SOTOMAYOR, J., dissenting

529 U. S., at 430. Under the warden’s argument, a peti
tioner who did not develop the record in state court, what
ever the reason, would be barred from presenting evidence
to the federal court. In rejecting that argument, we
observed:
     “A prisoner who developed his claim in state court and
     can prove the state court’s decision was ‘contrary to,
     or involved an unreasonable application of, clearly es
     tablished Federal law, as determined by the Supreme
     Court of the United States,’ is not barred from obtain
     ing relief by §2254(d)(1). If the opening clause of
     §2254(e)(2) covers a request for an evidentiary hear
     ing on a claim which was pursued with diligence but
     remained undeveloped in state court because, for in
     stance, the prosecution concealed the facts, a prisoner
     lacking clear and convincing evidence of innocence
     could be barred from a hearing on the claim even if he
     could satisfy §2254(d).” Id., at 434 (citation omitted;
     emphasis added).
A petitioner in the latter situation would almost certainly
be unable to “satisfy §2254(d)” without introducing the
concealed facts in federal court. This passage thus reflects
our understanding that, in some circumstances, a peti
tioner might need an evidentiary hearing in federal court
to prove the facts necessary to satisfy §2254(d). To avoid
foreclosing habeas relief for such petitioners, we concluded
that §2254(e)(2) could not bear the warden’s “harsh read
ing,” which essentially would have held petitioners strictly
at fault for their inability to develop the facts in state
court. Ibid. The majority today gives an equally “harsh
reading” to §2254(d)(1) to achieve the result we rejected in
Michael Williams.12
——————
  12 The majority claims that Michael Williams supports its reading of

§2254(d)(1). With respect to one claim asserted by the petitioner, we
observed that “[t]he Court of Appeals rejected this claim on the merits
16                   CULLEN v. PINHOLSTER

                      SOTOMAYOR, J., dissenting

   None of the other cases cited by the majority supports
its result. In Williams v. Taylor, 529 U. S. 362 (2000)
(Terry Williams), we interpreted §2254(d)(1) to ask
whether the state-court decision “identifies the correct
governing legal principle from this Court’s decisions but
unreasonably applies that principle to the facts of the
prisoner’s case.” Id., at 413. However, we had no reason
to decide whether the §2254(d)(1) inquiry was limited to
the state-court record, as the District Court did not hold
an evidentiary hearing in that case. See id., at 372.
   In Holland v. Jackson, we stated that “we have made
clear that whether a state court’s decision was unreason
able must be assessed in light of the record the court had
before it.” 542 U. S., at 652. In the next sentence, how
ever, we observed that the evidence at issue “could have
been the subject of an evidentiary hearing by the District
Court, but only if respondent was not at fault in failing to
develop that evidence in state court.” Id., at 652–653. We
proceeded to find that the evidence was not properly ad
mitted under §2254(e)(2) before concluding that the Court
of Appeals had erred in its §2254(d)(1) analysis. Id., at
653; see also Bradshaw v. Richey, 546 U. S. 74, 79 (2005)
(per curiam).
   In sum, our cases reflect our recognition that it is some
times appropriate to consider new evidence in deciding
whether a petitioner can satisfy §2254(d)(1). In reading
our precedent to require the opposite conclusion, the ma
jority disregards the concerns that motivated our decision
in Michael Williams: Some petitioners, even if diligent,
——————
under §2254(d)(1), so it is unnecessary to reach the question whether
§2254(e)(2) would permit a hearing on the claim.” 529 U. S., at 444.
That statement merely reflects the fact that the Court of Appeals had
rejected that claim under §2254(d)(1) without considering whether the
petitioner was entitled to a hearing because the petitioner had not
requested a hearing on that claim. See Williams v. Taylor, 189 F. 3d
421, 425, 428–429 (CA4 1999).
                      Cite as: 563 U. S. ____ (2011)                      17

                        SOTOMAYOR, J., dissenting

may be unable to develop the factual record in state court
through no fault of their own. We should not interpret
§2254(d)(1) to foreclose these diligent petitioners from
accessing the Great Writ when the state court will not
consider the new evidence and could not reasonably have
reached the same conclusion with the new evidence before
it.
                          II
  I also disagree with the Court’s conclusion that the
Court of Appeals erred in holding that Pinholster had
satisfied §2254(d)(1) on the basis of the state-court
record.13
                              A
  The majority omits critical details relating to the per
formance of Pinholster’s trial counsel, the mitigating
evidence they failed to discover, and the history of these
proceedings. I therefore highlight several aspects of the
facts and history of this case.

——————
  13 I agree with the majority that the state-court record in this case
consists of “the ‘allegations of [the] habeas corpus petition . . . and . . .
any matter of record pertaining to the case.’ ” Ante, at 16, n. 12 (quot
ing In re Hochberg, 2 Cal. 3d 870, 874, n. 2, 471 P. 2d 1, 3–4, n. 2
(1970); some internal quotation marks omitted).
   The majority does not decide which of the two state-court decisions
should be reviewed. See ante, at 15, n. 11. One amicus argues that
Pinholster must prove that both state-court decisions involved an
unreasonable application of law. See Brief for Criminal Justice Legal
Foundation as Amicus Curiae 26. This argument is based on amicus’
understanding that the California Supreme Court rejected the second
petition as successive and, alternatively, on the merits. The State has
not argued, however, that the second ruling rests on a procedural
ground. See ante, at 6, n. 2. When a state court denies two petitions on
the merits and the difference between the petitions is that the second
petition contains additional evidence supporting the petitioner’s claim,
I see no reason why the petitioner must independently show that the
first decision was unreasonable.
18                 CULLEN v. PINHOLSTER

                   SOTOMAYOR, J., dissenting

                            1
  After the jury returned a guilty verdict, the court in
structed the jury to return six days later for the penalty
phase. This prompted discussion at sidebar regarding
whether the State had provided notice of its intent to offer
aggravating evidence. Pinholster’s court-appointed attor
ney, Wilbur Dettmar, argued that the State should be
precluded from offering aggravating evidence:
     “I am not presently prepared to offer anything by way
     of mitigation. If I was going to proceed on mitigation,
     the people would have the right to rebuttal with or
     without notice.
        “I took the position, since the people had not given
     notice, I had not prepared any evidence by way of miti
     gation. I would submit it on that basis.” 52 Re
     porter’s Tr. 7250 (hereinafter Tr.) (emphasis added).
Undoubtedly anticipating that counsel might need addi
tional time to prepare an adequate mitigation defense, the
court asked Dettmar whether a continuance would be
helpful in the event it ruled against him. He declined the
offer on the spot, stating: “I think we would probably still
go forward on Monday. Clearly the one person that comes
to mind is the defendant’s mother. How much beyond that
I don’t know. I don’t think the pa[ss]age of time would
make a great deal of difference.” Id., at 7257–7258. After
hearing testimony, the court denied Pinholster’s motion to
preclude aggravating evidence.
   At the penalty phase, defense counsel called only one
witness: Pinholster’s mother, Burnice Brashear. Brashear
testified that Pinholster “never really wanted for anything
at home too much” and “had everything normally materi
alwise that most people have.” Id., at 7395. She said that
Pinholster was “different” from his siblings, whom she
characterized as “basically very good children.” Id., at
7401–7402. Pinholster, she said, had a “friendly” relation
                    Cite as: 563 U. S. ____ (2011)                19

                      SOTOMAYOR, J., dissenting

ship with his stepfather, although his stepfather “some
times would lose his temper” with Pinholster, who “had a
mind of his own.” Id., at 7392–7393; see also id., at 7293
(stating that his stepfather was “at times” “abusive or
near abusive”).
   Brashear provided brief testimony regarding Pinhol
ster’s childhood. She described two car accidents—one
when she ran over him in the driveway and one when he
went through the windshield. Id., at 7389–7391. She
stated that he started failing school in the first grade and
that the school eventually “sent him to [an] educationally
handicapped class.” Id., at 7393–7394. When Pinholster
was 10, a psychologist recommended placing him in a
mental institution, but she “didn’t think he was that far
gone.” Id., at 7395. A few years later, she testified, he
spent six months in a state hospital for emotionally handi
capped children. Id., at 7402.
   According to Brashear, Pinholster had suffered from
epilepsy since age 18, when he was beaten in jail. Id.,
at 7397. She said that her family doctor, Dr. Dubin,
had given him medication to treat the epilepsy. Ibid.
Brashear also suggested that Pinholster did not have long
to live, stating that he had “a chip in his head floating
around” and that “they don’t think—he won’t be here very
much longer anyway.”14 Ibid.
   In closing argument, the prosecutor ridiculed Brashear’s
testimony. See 53 id., at 7442 (“She said his stepfather
disciplined him. So what? I am sure you have all disci
plined your children. I was disciplined myself”); ibid. (“He
was run over by a car when he was three years old. That’s
very unfortunate. There is no evidence of any brain dam
age. A lot of children get dropped, fall from their cribs or
——————
 14 The judge instructed the jury to disregard this testimony upon

motion by the prosecutor, but the prosecutor then discussed the testi
mony in her closing argument. See infra, at 33–34.
20                   CULLEN v. PINHOLSTER

                     SOTOMAYOR, J., dissenting

whatever”); id., at 7444–7445 (“I submit to you that if this
defendant truly had epilepsy, . . . a doctor would have been
brought in to tell you that. Medical records, something”).
The prosecutor also highlighted Brashear’s testimony
about Pinholster’s stable home environment, arguing, “He
came from a good home. You heard that he was not a
deprived child. Had many things going for him, probably
more than many children.” Id., at 7442.
  Notwithstanding the meager mitigation case presented
by Pinholster’s counsel, it took the jury two days to reach a
decision to sentence Pinholster to death. His counsel later
moved to modify the sentence to life imprisonment. In
denying the motion, the trial judge stated, “The evidence
which the defense offered concerning the defendant’s
extenuation was merely some testimony from his mother
that was not persuasive. His mother did not, in the court’s
opinion, present any evidence which the court would find
to be a moral justification or extenuation for his conduct.
No witness supplied such evidence.” 54 id., at 7514.
                                 2
  After his conviction and sentence were affirmed on
appeal, Pinholster filed a habeas petition in the California
Supreme Court alleging, among other things, that his
counsel had “unreasonably failed to investigate, prepare
and present available mitigating evidence during penalty
phase.” Record ER–103.
  Pinholster’s state-court petition included 121 exhibits.
In a series of declarations, his trial attorney Harry
Brainard (who had by then been disbarred) confirmed
what Dettmar had forthrightly told the trial court:
Brainard and Dettmar neither expected nor prepared to
present mitigation evidence.15 See id., at ER–333 (“Mr.

——————
 15 By the time of Pinholster’s state-court habeas petition, Dettmar

was deceased.
                     Cite as: 563 U. S. ____ (2011)                  21

                      SOTOMAYOR, J., dissenting

Dettmar and I did not prepare a case in mitigation. We
felt there would be no penalty phase hearing inasmuch as
we did not receive written notice of evidence in aggrava
tion pursuant to Penal Code §190.3”). Brainard further
confirmed what was apparent from the mitigation case
they eventually put on: They conducted virtually no miti
gation investigation. See id., at ER–182 (“I have no recol
lection of Mr. Dettmar having secured or reviewed any of
Scott’s medical records, nor did I see any of Scott’s medical
records. So far as I recollect, neither Mr. Dettmar nor
myself interviewed any of Scott’s previous medical provid
ers”); id., at ER–183 (“I do not recall interviewing or at
tempting to interview Scott’s family members or any other
persons regarding penalty phase testimony, except Mrs.
Brashears [sic]”); ibid. (“I have no recollection of seeing or
attempting to secure Scott’s school records, juvenile re
cords, medical records, or records of prior placements”);
ibid. (“I have no recollection of interviewing or attempting
to interview Scott’s former school teachers, counselors, or
juvenile officers”).16
   Statements by relatives (none of whom trial counsel had
attempted to interview regarding Pinholster’s background)
and documentary evidence revealed that the picture of
Pinholster’s family life painted by his mother at trial was
false. Pinholster was “raised in chaos and poverty.” Id.,
at ER–312. A relative remembered seeing the children
mix together flour and water in an attempt to get some
thing to eat. Pinholster’s stepfather beat him several
times a week, including at least once with a two-by-four
board. “There was so much violence in [the] home” that
Pinholster’s brother “dreaded coming home each day.” Id.,
at ER–313. Pinholster’s half sister was removed from the
home as a result of a beating by his stepfather.
——————
  16 Counsel’s billing records, which were before the California Supreme

Court as part of the trial record, confirmed Brainard’s recollection.
22                   CULLEN v. PINHOLSTER

                      SOTOMAYOR, J., dissenting

  Documentary evidence showed, directly contrary to
Brashear’s trial testimony, that Pinholster’s siblings had
very troubled pasts. Pinholster’s elder brother was ar
rested for armed burglary, robbery, and forcible rape of a
14-year-old with a deadly weapon. While in custody, he
was diagnosed as “catatonic-like” and “acutely psychotic,
probably suffering some type of schizophrenia.” Id., at
ER–219, ER–224. He later committed suicide.17 Pinhol
ster’s half sister, a recovering alcoholic, had been made a
ward of the juvenile court for prostitution and forcible
sexual battery on a 14-year-old.
  Pinholster’s petition and exhibits described a long his
tory of emotional disturbance and neurological problems.
A former schoolteacher stated that, as a child, Pinholster
“seemed incapable of relating either to his peers or to
adults,” that “[i]t was even hard to maintain eye contact
with him,” and that “[h]is hyperactivity was so extreme
that [she] formed the opinion it probably had an organic
base.” Id., at ER–231. School records revealed that he
“talk[ed] to self continuously,” had “many grimaces,”
fought in his sleep, and could “control self for only 1 hour
per day.” Id., at ER–230, ER–233. He “show[ed] progres
sive deterioration each semester since Kindergarten.” Id.,
at ER–230. School officials recommended placement in a
school for emotionally handicapped students and referral
to a neurologist. At age nine, he had an abnormal EEG,
revealing “an organic basis for his behavior.” Id., at ER–
157, ER–234. Just months before the homicides, a doctor
recommended placement in the Hope Psychiatric Insti
tute, but this did not occur.
  This and other evidence attached to the petition was

——————
  17 Accordingto Pinholster’s half sister, “The death of our brother Al
vin was a severe emotional blow to me and to Scott. I believed Scott’s
substance abuse (heroin) arose following and as a result of Alvin’s
death.” Record ER–314.
                     Cite as: 563 U. S. ____ (2011)                  23

                      SOTOMAYOR, J., dissenting

summarized in a declaration by Dr. George Woods. Dr.
Woods opined that Pinholster “suffer[ed] from severe and
long standing seizure disorders,” id., at ER–156, that his
childhood head traumas “may have been the precipitating
factors for [his] seizure disorder,” id., at ER–157, and that
he suffered from bipolar mood disorder. He pointed to
trial testimony that immediately before the burglary on
the night of the homicides, Pinholster announced that he
“ ‘ha[d] a message from God’ ”—which Dr. Woods believed
to reflect “[a]uditory hallucinations” and “severe psycho
sis.” Id., at ER–169. He concluded that at the time of the
homicides Pinholster “was suffering from bipolar mood
disorder with psychotic ideation and was suffering a com
plex partial seizure.” Id., at ER–170. He also observed
that Pinholster’s “grossly dysfunctional family, the abuse
he received as a child, his history of suffering from sub
stantial seizure and mood disorders, his frequently un
treated psychiatric and psychological disabilities and his
educational handicaps were relevant circumstances which
would extenuate the gravity of the crime.” Id., at ER–171.
   On the basis of Pinholster’s submission, the California
Supreme Court denied Pinholster’s ineffective-assistance
of-counsel claim.
   Pinholster then filed a habeas petition in Federal Dis
trict Court. He included an additional exhibit: a declara
tion by Dr. John Stalberg, a psychiatrist who had hastily
examined Pinholster and produced a two-page report in
the middle of the original trial.18 After reviewing the new
material collected by Pinholster’s habeas counsel, Dr.
Stalberg stated that the available evidence showed a
——————
  18 Counsel had arranged for Dr. Stalberg to examine Pinholster in the

middle of his original trial. The only documents they provided to him
were police reports relating to the case and a 1978 probation report. In
a two-page report that focused primarily on Pinholster’s mental state at
the time of the offenses, Dr. Stalberg concluded that Pinholster had
“psychopathic personality traits.” Id., at ER–187.
24                    CULLEN v. PINHOLSTER

                      SOTOMAYOR, J., dissenting

familial history of “severe psychiatric disorders,” “a history
of seizure disorders of unknown etiology,” “repeated head
traumas,” “an abnormal EEG,” and “evidence of mental
disturbance during Mr. Pinholster’s childhood and some
degree of brain damage.” Id., at ER–493. He also opined
that “there [was] voluminous mitigating evidence which
includes a childhood of physical abuse, emotional neglect,
and a family history of mental illness and criminal behav
ior.” Id., at ER–494.
  The District Court stayed the federal proceedings while
Pinholster sought state-court review of claims the District
Court deemed unexhausted. Pinholster’s second habeas
submission to the California Supreme Court included
Stalberg’s declaration. That court summarily denied
Pinholster’s petition on the merits.
  Pinholster returned to Federal District Court and filed
an amended petition. After an evidentiary hearing, the
District Court concluded that Pinholster had demon
strated deficient performance and prejudice under Strick
land.19 The Ninth Circuit, sitting en banc, affirmed. 590
F. 3d 651.
                             B
  As the majority notes, Pinholster’s claim arises under
Strickland v. Washington. “The benchmark for judging
any claim of ineffectiveness [under Strickland] must be
whether counsel’s conduct so undermined the proper
functioning of the adversarial process that the trial cannot
be relied on as having produced a just result.” 466 U. S.,

——————
  19 The District Court based its decision on the evidence adduced at an

evidentiary hearing. The District Court did not apply 28 U. S. C.
§2254(d) because it thought, erroneously, that the California Supreme
Court had not adjudicated Pinholster’s claim on the merits. App. to
Pet. for Cert. 257. For the reasons I discuss, however, the District
Court could have concluded that Pinholster had satisfied §2254(d)(1) on
the basis of the state-court record alone.
                  Cite as: 563 U. S. ____ (2011)             25

                    SOTOMAYOR, J., dissenting

at 686. To satisfy this benchmark, a defendant must show
both that “counsel’s performance was deficient” and that
“the deficient performance prejudiced the defense.” Id., at
687.
   When §2254(d)(1) applies, the question is whether “ ‘fair
minded jurists could disagree’ on the correctness of the
state court’s decision.” Harrington, 562 U. S., at ___ (slip
op., at 11) (quoting Yarborough v. Alvarado, 541 U. S. 652,
664 (2004)). When the state court rejected a Strickland
claim on the pleadings assuming the allegations to be
true, as here, see ante, at 16, n. 12, the federal court must
ask whether “there is any reasonable argument” support
ing the state court’s conclusion that the petitioner’s allega
tions did not state a claim, Harrington, 562 U. S., at ___
(slip op., at 16). This standard is “difficult,” but not im
possible, “to meet.” Id., at ___ (slip op., at 12). This case is
one in which fairminded jurists could not disagree that the
state court erred.
                             C
   Under Strickland, “the defendant must show that coun
sel’s representation fell below an objective standard of
reasonableness,” measured according to “prevailing pro
fessional norms.” 466 U. S., at 688. We “indulge a strong
presumption that counsel’s conduct falls within the wide
range of reasonable professional assistance.” Id., at 689.
When §2254(d) applies, federal-court review is “ ‘doubly’ ”
deferential. Harrington, 562 U. S., at ___ (slip op., at 16)
(quoting Knowles v. Mirzayance, 556 U. S. ___, ___ (2009)
(slip op., at 11)). In the present AEDPA posture, “[t]he
question is whether there is any reasonable argument that
counsel satisfied Strickland’s deferential standard.” Har
rington, 562 U. S., at ___ (slip op., at 16). Here, there is
none.
   The majority surmises that counsel decided on a strat
egy “to get the prosecution’s aggravation witnesses ex
26                     CULLEN v. PINHOLSTER

                        SOTOMAYOR, J., dissenting

cluded for lack of notice, and if that failed, to put on Pin
holster’s mother.” Ante, at 19. This is the sort of “ ‘post
hoc rationalization’ for counsel’s decisionmaking that
contradicts the available evidence of counsel’s actions”
that courts cannot indulge. Harrington, 562 U. S., at ___
(slip op., at 20) (quoting Wiggins v. Smith, 539 U. S. 510,
526–527 (2003)). The majority’s explanation for counsel’s
conduct contradicts the best available evidence of counsel’s
actions: Dettmar’s frank, contemporaneous statement to
the trial judge that he “had not prepared any evidence by
way of mitigation.” 52 Tr. 7250. The majority’s conjecture
that counsel had in fact prepared a mitigation defense,
based primarily on isolated entries in counsel’s billing
records, requires it to assume that Dettmar was lying to
the trial judge.20
   In any event, even if Pinholster’s counsel had a strategic
reason for their actions, that would not automatically
render their actions reasonable. For example, had counsel
decided their best option was to move to exclude the ag
gravating evidence, it would have been unreasonable to
forgo a mitigation investigation on the hope that the mo
tion would be granted. With a client’s life at stake, it
would “flou[t] prudence,” Rompilla v. Beard, 545 U. S. 374,
——————
  20 The majority misleadingly cites entries showing that counsel were
preparing Brashear’s penalty phase testimony after counsel learned
that the State intended to present aggravation evidence. The cited
entries predating that event show only that counsel conducted about
one day’s worth of investigation—consisting of talking to Brashear and
researching epilepsy—two months before the penalty phase. See 3
Clerk’s Tr. 798 (1.5-hour phone call to Brashear on Jan. 13); id., at 864,
869 (3-hour meeting with Brashear regarding “childhood problems” on
Feb. 23); id., at 869 (3.5 hours for “[r]esearch re; epilepsy and conf. with
nurse” on Feb. 25). There is no evidence in the records that counsel
actually planned to present mitigating evidence. Indeed, their complete
failure to follow up on any of the information they learned in their
minimal investigation only confirms that they were not planning to
present mitigating evidence. See infra, at 29–31.
                  Cite as: 563 U. S. ____ (2011)           27

                   SOTOMAYOR, J., dissenting

389 (2005), for an attorney to rely on the possibility that
the court might preclude aggravating evidence pursuant
to a “legal technicality” without any backup plan in place
in case the court denied the motion, ante, at 19. No rea
sonable attorney would pursue such a risky strategy. I do
not understand the majority to suggest otherwise.
  Instead, I understand the majority’s conclusion that
counsel’s actions were reasonable to rest on its belief that
they did have a backup plan: a family-sympathy defense.
In reaching this conclusion, the majority commits the
same Strickland error that we corrected, applying
§2254(d)(1), in Wiggins: It holds a purportedly “tactical
judgment” to be reasonable without assessing “the ade
quacy of the investigatio[n] supporting [that] judgmen[t],”
539 U. S., at 521. As we stated in Strickland:
    “[S]trategic choices made after thorough investigation
    of law and facts relevant to plausible options are vir
    tually unchallengeable; and strategic choices made af
    ter less than complete investigation are reasonable
    precisely to the extent that reasonable professional
    judgments support the limitations on investigation.
    In other words, counsel has a duty to make reasonable
    investigations or to make a reasonable decision that
    makes particular investigations unnecessary. In any
    ineffectiveness case, a particular decision not to inves
    tigate must be directly assessed for reasonableness in
    all the circumstances, applying a heavy measure of
    deference to counsel’s judgments.” 466 U. S., at 690–
    691.
We have repeatedly applied this principle since Strick
land. See Sears v. Upton, 561 U. S. ___, ___ (2010) (per
curiam) (slip op., at 9); Porter v. McCollum, 558 U. S. ___,
___ (2009) (per curiam) (slip op., at 10); Wiggins, 539 U. S.,
28                    CULLEN v. PINHOLSTER

                      SOTOMAYOR, J., dissenting

at 527; Terry Williams, 529 U. S., at 396.21
   As these cases make clear, the prevailing professional
norms at the time of Pinholster’s trial required his attor
neys to “conduct a thorough investigation of the defen
dant’s background,” ibid. (citing 1 ABA Standards for
Criminal Justice 4–4.1, commentary, p. 4–55 (2d ed. 1980)
(hereinafter ABA Standards)), or “to make a reasonable
decision that makes particular investigations unneces
sary,” Strickland, 466 U. S., at 691.22 “In judging the
defense’s investigation, as in applying Strickland gener
ally, hindsight is discounted by pegging adequacy to ‘coun
sel’s perspective at the time’ investigative decisions are
made, and by giving a ‘heavy measure of deference to
counsel’s judgments.’ ” Rompilla, 545 U. S., at 381 (quot
ing Strickland, 466 U. S., at 689, 691; citation omitted). In
some cases, “reasonably diligent counsel may draw a line
when they have good reason to think further investigation
would be a waste.” Rompilla, 545 U. S., at 383; see, e.g.,
Bobby v. Van Hook, 558 U. S. ___, ___ (2009) (per curiam)
(slip op., at 8); Burger v. Kemp, 483 U. S. 776, 794–795
(1987). In other cases, however, Strickland requires fur
ther investigation.

——————
   21 I do not doubt that a decision to present a family-sympathy mitiga

tion defense might be consistent “with the standard of professional
competence in capital cases that prevailed in Los Angeles in 1984” in
some cases. Ante, at 24. My point is that even if counsel made a
strategic decision to proceed with such a defense, that decision was
unreasonable because it was based on an unreasonably incomplete
investigation.
   22 See also 1 ABA Standards 4–4.1, commentary, at 4–55 (“Informa

tion concerning the defendant’s background, education, employment
record, mental and emotional stability, family relationships, and the
like, will be relevant, as will mitigating circumstances surrounding the
commission of the offense itself”). As we recognized in Strickland, the
ABA Standards, though not dispositive, “are guides to determining
what is reasonable.” 466 U. S., at 688; see also Wiggins v. Smith, 539
U. S. 510, 524 (2003).
                      Cite as: 563 U. S. ____ (2011)                    29

                       SOTOMAYOR, J., dissenting

   Wiggins is illustrative of the competence we have re
quired of counsel in a capital case. There, counsel’s in
vestigation was limited to three sources: psychological
testing, a presentencing report, and Department of Social
Services records. 539 U. S., at 523–524. The records
revealed that the petitioner’s mother was an alcoholic,
that he displayed emotional difficulties in foster care, that
he was frequently absent from school, and that on one
occasion, his mother left him alone for days without food.
Id., at 525. In these circumstances, we concluded, “any
reasonably competent attorney would have realized that
pursuing these leads was necessary to making an in
formed choice among possible defenses.” Ibid. Accord
ingly, we held, the state court’s assumption that counsel’s
investigation was adequate was an unreasonable applica
tion of Strickland. 539 U. S., at 528.23
   This case is remarkably similar to Wiggins. As the
majority reads the record, counsel’s mitigation investiga
tion consisted of talking to Pinholster’s mother, consulting
with Dr. Stalberg, and researching epilepsy.24 Ante, at 20.
What little information counsel gleaned from this “rudi
mentary” investigation, Wiggins, 539 U. S., at 524, would
have led any reasonable attorney “to investigate further,”
id., at 527. Counsel learned from Pinholster’s mother that
he attended a class for educationally handicapped chil
dren, that a psychologist had recommended placing him in
a mental institution, and that he spent time in a state
——————
  23 As the majority notes, see ante, at 24–25, Wiggins’ trial counsel

acknowledged that the investigation he conducted was inconsistent
with standard practice in Maryland. See 539 U. S., at 524. We inde
pendently concluded, however, that the investigation “was also unrea
sonable in light of what counsel actually discovered in the . . . records.”
Id., at 525 (emphasis added).
  24 The majority also posits that Brainard likely spent time preparing

Pinholster’s brother Terry. However, Terry averred in a declaration
that Pinholster’s attorneys “never asked [him] any questions relating to
Scott’s background or [their] family history.” Record ER–313.
30                CULLEN v. PINHOLSTER

                   SOTOMAYOR, J., dissenting

hospital for emotionally handicapped children. They knew
that Pinholster had been diagnosed with epilepsy.
   “[A]ny reasonably competent attorney would have real
ized that pursuing” the leads suggested by this informa
tion “was necessary to making an informed choice among
possible defenses.” Id., at 525; see also Penry v. Lynaugh,
492 U. S. 302, 319 (1989) (“[E]vidence about the defen
dant’s background and character is relevant because of the
belief, long held by this society, that defendants who
commit criminal acts that are attributable to a disadvan
taged background, or to emotional and mental problems,
may be less culpable than defendants who have no such
excuse” (internal quotation marks omitted)). Yet counsel
made no effort to obtain the readily available evidence
suggested by the information they learned, such as Pin
holster’s schooling or medical records, or to contact
Pinholster’s school authorities. They did not contact Dr.
Dubin or the many other health-care providers who had
treated Pinholster. Put simply, counsel “failed to act while
potentially powerful mitigating evidence stared them in
the face.” Bobby, 558 U. S., at ___ (slip op., at 8) (citing
Wiggins, 539 U. S., at 525).
   The “impediments” facing counsel, ante, at 21, did not
justify their minimal investigation. It is true that Pinhol
ster was “an unsympathetic client.” Ibid. But this fact
compounds, rather than excuses, counsel’s deficiency in
ignoring the glaring avenues of investigation that could
explain why Pinholster was the way he was. See Sears,
561 U. S., at ___ (slip op., at 7) (“This evidence might not
have made Sears any more likable to the jury, but it might
well have helped the jury understand Sears, and his hor
rendous acts—especially in light of his purportedly stable
upbringing”). Nor can Dr. Stalberg’s two-page report,
which was based on a very limited record and focused
primarily on Pinholster’s mental state at the time of
the homicides, excuse counsel’s failure to investigate the
                     Cite as: 563 U. S. ____ (2011)                  31

                      SOTOMAYOR, J., dissenting

broader range of potential mitigating circumstances.
   “The record of the actual sentencing proceedings under
scores the unreasonableness of counsel’s conduct by
suggesting that their failure to investigate thoroughly re
sulted from inattention, not reasoned strategic judgment.”
Wiggins, 539 U. S., at 526. Dettmar told the trial judge
that he was unprepared to present any mitigation evi
dence. The mitigation case that counsel eventually put on
can be described, at best, as “halfhearted.” Ibid. Counsel
made no effort to bolster Brashear’s self-interested testi
mony with school or medical records, as the prosecutor
effectively emphasized in closing argument. And because
they did not pursue obvious leads, they failed to recognize
that Brashear’s testimony painting Pinholster as the bad
apple in a normal, nondeprived family was false.
   In denying Pinholster’s claim, the California Supreme
Court necessarily overlooked Strickland’s clearly estab
lished admonition that “strategic choices made after less
than complete investigation are reasonable precisely to
the extent that reasonable professional judgments support
the limitations.” 466 U. S., at 690–691. As in Wiggins, in
light of the information available to Pinholster’s counsel, it
is plain that “reasonable professional judgments” could not
have supported their woefully inadequate investigation.25
466 U. S., at 691. Accordingly, the California Supreme
Court could not reasonably have concluded that Pinholster
——————
  25 The majority chastises the Court of Appeals for “attributing strict
rules to this Court’s recent case law.” Ante, at 24. I agree that courts
should not interpret our cases to prescribe strict rules regarding the
required scope of mitigation investigations. See Rompilla v. Beard, 545
U. S. 374, 394 (2005) (O’Connor, J., concurring) (noting “our longstand
ing case-by-case approach to determining whether an attorney’s per
formance was unconstitutionally deficient under Strickland”). The
Ninth Circuit, however, did no such thing. It appropriately gave
thoughtful consideration to the guideposts contained in these cases,
just as we have previously done. See, e.g., Bobby v. Van Hook, 558
U. S. ___, ___ (2009) (per curiam) (slip op., at 8).
32                CULLEN v. PINHOLSTER

                   SOTOMAYOR, J., dissenting

had failed to allege that his counsel’s investigation was
inadequate under Strickland.
                             D
   The majority also concludes that the California Supreme
Court could reasonably have concluded that Pinholster did
not state a claim of prejudice. This conclusion, in light of
the overwhelming mitigating evidence that was not before
the jury, is wrong. To establish prejudice, “[t]he defendant
must show that there is a reasonable probability that, but
for counsel’s unprofessional errors, the result of the pro
ceeding would have been different.” Id., at 694. When a
habeas petitioner challenges a death sentence, “the ques
tion is whether there is a reasonable probability that,
absent the errors, the sentencer . . . would have concluded
that the balance of aggravating and mitigating circum
stances did not warrant death.” Id., at 695. This inquiry
requires evaluating “the totality of the available mitiga
tion evidence—both that adduced at trial, and the evi
dence adduced in the habeas proceeding—in reweighing it
against the evidence in aggravation.” Terry Williams, 529
U. S., at 397–398. The ultimate question in this case is
whether, taking into account all the mitigating and aggra
vating evidence, “there is a reasonable probability that at
least one juror would have struck a different balance.”
Wiggins, 539 U. S., at 537; see Cal. Penal Code Ann.
§190.4(b) (West 2008) (requiring a unanimous jury verdict
to impose a death sentence).
                              1
  Like the majority, I first consider the aggravating and
mitigating evidence presented at trial. By virtue of its
verdict in the guilt phase, the jury had already concluded
that Pinholster had stabbed and killed the victims. As the
majority states, the jury saw Pinholster “revel” in his
history of burglaries during the guilt phase. Ante, at 26.
                     Cite as: 563 U. S. ____ (2011)                   33

                       SOTOMAYOR, J., dissenting

The jury heard evidence of Pinholster’s violent tendencies:
He had kidnapped someone with a knife, cut a person in
the arm with a razor, and had a history of hitting and
kicking people. He threatened to kill the State’s lead
witness. And he had an extensive disciplinary record in
jail.
  Brashear offered brief testimony that was apparently
intended to be mitigating. See supra, at 19–20; see also
ante, at 27–28.26 However, as the prosecutor argued,
Brashear was not a neutral witness. See 53 Tr. 7441 (“A
mother clearly loves her son, ladies and gentlemen.
Clearly not the most unbiased witness in the world”).
Notwithstanding Brashear’s obvious self-interest, counsel
failed to offer readily available, objective evidence that
would have substantiated and expanded on her testimony.
Their failure to do so allowed the prosecutor to belittle her
testimony in closing argument. See supra, at 19–20. And
Brashear’s statement that Pinholster would not be alive
much longer because he had “a chip in his head floating
around,” 52 Tr. 7397, could only have undermined her
credibility, as the prosecutor urged, see 53 id., at 7447
(“Does she want you to believe sometime before he got to
——————
  26 The majority mischaracterizes several aspects of Brashear’s testi

mony. Although Brashear testified that the family “didn’t have lots of
money,” she followed up that comment by stating that Pinholster did
not bring friends to the house because “it was too nice a house.” 52 Tr.
7404. The prosecutor did not understand Brashear to have testified
that Pinholster’s childhood was deprived. See 53 id., at 7442 (“You
heard that he was not a deprived child”). Nor did the California Su
preme Court on direct appeal. People v. Pinholster, 1 Cal. 4th 865, 910,
824 P. 2d 571, 587 (1992).
  Brashear did testify that Pinholster’s stepfather tried to “discipline”
him and that he was “at times” “abusive or near abusive.” 52 Tr. 7392–
7393. She suggested, however, that Pinholster deserved the “disci
pline” he received. See, e.g., id., at 7392 (“Scott was always—he had a
mind of his own”). It is unlikely the jury understood Brashear to be
suggesting that her husband routinely beat Pinholster. The prosecutor
did not come away with this understanding. See 53 id., at 7442.
34                 CULLEN v. PINHOLSTER

                    SOTOMAYOR, J., dissenting

country jail some doctor looked in a crystal ball and
said, ‘In three years you are going to die’? That’s ridicu
lous”). The trial judge was thoroughly unimpressed with
Brashear’s testimony. See supra, at 20.
   Moreover, the evidence presented in Pinholster’s state
court petition revealed that Brashear distorted facts in her
testimony in ways that undermined Pinholster’s mitiga
tion case. As in Sears, 561 U. S., at ___ (slip op., at 3), the
prosecutor used Brashear’s testimony that Pinholster
came from a good family against him. See 53 Tr. 7442.
   In sum, counsel presented little in the way of mitigating
evidence, and the prosecutor effectively used their half
hearted attempt to present a mitigation case to advocate
for the death penalty. The jury nonetheless took two days
to reach a decision to impose a death sentence.
                             2
  The additional mitigating evidence presented to the
California Supreme Court “adds up to a mitigation case
that bears no relation” to Brashear’s unsubstantiated
testimony. Rompilla, 545 U. S., at 393.
  Assuming the evidence presented to the California
Supreme Court to be true, as that court was required to
do, the new mitigating evidence presented to that court
would have shown that Pinholster was raised in “chaos
and poverty.” Record ER–312. The family home was filled
with violence. Pinholster’s siblings had extremely trou
bled pasts. There was substantial evidence of “mental
disturbance during Mr. Pinholster’s childhood and some
degree of brain damage.” Id., at ER–493.
  Dr. Woods concluded that Pinholster’s aggressive con
duct resulted from bipolar mood disorder. Just months
before the murders, a doctor had recommended that Pin
holster be sent to a psychiatric institute. Dr. Woods also
explained that Pinholster’s bizarre behavior before the
murders reflected “[a]uditory hallucinations” and “severe
                  Cite as: 563 U. S. ____ (2011)           35

                   SOTOMAYOR, J., dissenting

psychosis.” Id., at ER–169. The available records con
firmed that Pinholster suffered from longstanding seizure
disorders, which may have been caused by his childhood
head injuries.
   On this record, I do not see how it can be said that “[t]he
‘new’ evidence largely duplicated the mitigation evidence
at trial.” Ante, at 29; see Arizona v. Fulminante, 499 U. S.
279, 298–299 (1991) (evidence is not “merely cumulative”
if it corroborates other evidence that is “unbelievable” on
its own). Brashear’s self-interested testimony was not
confirmed with objective evidence, as the prosecutor high
lighted. The new evidence would have “destroyed the
[relatively] benign conception of [Pinholster’s] upbringing”
presented by his mother. Rompilla, 545 U. S., at 391. The
jury heard no testimony at all that Pinholster likely suf
fered from brain damage or bipolar mood disorder, and
counsel offered no evidence to help the jury understand
the likely effect of Pinholster’s head injuries or his bizarre
behavior on the night of the homicides. The jury heard no
testimony recounting the substantial evidence of Pinhol
ster’s likely neurological problems. And it heard no medi
cal evidence that Pinholster suffered from epilepsy.
   The majority responds that “much” of Pinholster’s new
mitigating evidence “is of questionable mitigating value.”
Ante, at 29. By presenting psychiatric testimony, it con
tends, “Pinholster would have opened the door to rebuttal
by a state expert.” Ibid. But, because the California
Supreme Court denied Pinholster’s petition on the plead
ings, it had no reason to know what a state expert might
have said. Moreover, given the record evidence, it is rea
sonably probable that at least one juror would have cred
ited his expert. In any event, even if a rebuttal expert
testified that Pinholster suffered from antisocial personal
ity disorder, this would hardly have come as a surprise to
the jury. See ante, at 22 (describing Pinholster as a “psy
chotic client whose performance at trial hardly endeared
36                     CULLEN v. PINHOLSTER

                        SOTOMAYOR, J., dissenting

him to the jury”). It is for this reason that it was espe
cially important for counsel to present the available evi
dence to help the jury understand Pinholster. See Sears,
561 U. S., at ___ (slip op., at 6–7).
   Had counsel conducted an adequate investigation, the
judge and jury would have heard credible evidence show
ing that Pinholster’s criminal acts and aggressive tenden
cies were “attributable to a disadvantaged background, or
to emotional and mental problems.” Penry, 492 U. S., at
319 (internal quotation marks omitted). They would have
learned that Pinholster had the “ ‘kind of troubled history
we have declared relevant to assessing a defendant’s
moral culpability.’ ” Porter, 558 U. S., at ___ (slip op., at 12)
(quoting Wiggins, 539 U. S., at 535). Applying Strickland,
we have repeatedly found “a reasonable probability,” 466
U. S., at 694, that the sentencer would have reached a
different result had counsel presented similar evidence.
See, e.g., Porter, 558 U. S., at ___ (slip op., at 12–13) (evi
dence of the defendant’s childhood history of physical
abuse, brain abnormality, limited schooling, and heroic
military service); Rompilla, 545 U. S., at 392 (evidence of
severe abuse and neglect as a child, as well as brain
damage); Wiggins, 539 U. S., at 535 (evidence of the de
fendant’s “severe privation and abuse” as a child, home
lessness, and “diminished mental capacities”); Terry
Williams, 529 U. S., at 398 (evidence of childhood
mistreatment and neglect, head injuries, possible organic
mental impairments, and borderline mental retardation).
   The majority does not dispute the similarity between
this case and the cited cases. However, it criticizes the
Court of Appeals for relying on Rompilla and Terry Wil
liams on the ground that we reviewed the prejudice ques
tion de novo in those cases. See ante, at 31. I do not read
Terry Williams to review the prejudice question de novo.27
——————
 27 Terry   Williams held that the state court’s decision was “unreason
                     Cite as: 563 U. S. ____ (2011)                    37

                       SOTOMAYOR, J., dissenting

More fundamentally, however, I cannot agree with the
premise that “[t]hose cases . . . offer no guidance with
respect to whether a state court has unreasonably deter
mined that prejudice is lacking.” Ante, at 31 (emphasis
deleted). In each of these cases, we did not purport to
create new law; we simply applied the same clearly estab
lished precedent, Strickland, to a different set of facts.
Because these cases illuminate the kinds of mitigation
evidence that suffice to establish prejudice under Strick
land, they provide useful, but not dispositive, guidance for
courts to consider when determining whether a state court
has unreasonably applied Strickland.
   In many cases, a state court presented with additional
mitigation evidence will reasonably conclude that there is
no “reasonable probability that, but for counsel’s unprofes
sional errors, the result of the proceeding would have been
different.” Strickland, 466 U. S., at 694. This is not such
a case. Admittedly, Pinholster unjustifiably stabbed and
killed two people, and his history of violent outbursts and
burglaries surely did not endear him to the jury. But the
homicides did not appear premeditated. And the State’s
aggravation case was no stronger than in Rompilla and
Terry Williams. See 545 U. S., at 378, 383 (the defendant
committed murder by torture and had a significant history
of violent felonies, including a rape); 529 U. S., at 418
(Rehnquist, C. J., concurring in part and dissenting in
part) (the defendant had a lifetime of crime, and after the
murder he “savagely beat an elderly woman,” set a home
on fire, and stabbed a man (internal quotation marks
omitted)). Even on the trial record, it took the jury two
days to decide on a penalty. The contrast between the “not

—————— 

able in at least two respects”: (1) It applied the wrong legal standard,

see 529 U. S., at 397, and (2) it “failed to accord appropriate weight to 

the body of mitigation evidence available to trial counsel,” id., at 398.

We did not purport to conduct de novo review. 

38                CULLEN v. PINHOLSTER

                   SOTOMAYOR, J., dissenting

persuasive” mitigation case put on by Pinholster’s counsel,
54 Tr. 7514, and the substantial mitigation evidence at
their fingertips was stark. Given these considerations, it
is not a foregone conclusion, as the majority deems it, that
a juror familiar with his troubled background and psychi
atric issues would have reached the same conclusion
regarding Pinholster’s culpability. Fairminded jurists
could not doubt that, on the record before the California
Supreme Court, “there [was] a reasonable probability that
at least one juror would have struck a different balance.”
Wiggins, 539 U. S., at 537.
                            III
  The state-court record on its own was more than ade
quate to support the Court of Appeals’ conclusion that the
California Supreme Court could not reasonably have
rejected Pinholster’s Strickland claim. The additional
evidence presented in the federal evidentiary hearing only
confirms that conclusion.
                              A
   At the hearing, Pinholster offered many of the same
documents that were before the state habeas court. He
also offered his trial attorneys’ billing records, which were
before the state habeas court as part of the trial record. Of
the seven lay witnesses who testified at the hearing, six
had previously executed declarations in support of Pinhol
ster’s state-court petition. (The seventh, Pinholster’s
uncle, provided testimony cumulative of other testimony.)
   Two experts testified on Pinholster’s behalf; neither had
presented declarations to the state habeas court. The first
was Dr. Donald Olson, assistant professor of neurology
and neurological sciences and director of the Pediatric
Epilepsy Program at Stanford University Medical Center.
It appears that Pinholster retained Dr. Olson to rebut the
testimony of the expert disclosed by the State in the fed
                 Cite as: 563 U. S. ____ (2011)          39

                  SOTOMAYOR, J., dissenting

eral proceeding. See Decl. of Michael D. Abzug in Support
of Stipulated Ex Parte Application to Continue Eviden
tiary Hearing and Discovery Cut-Off and to Substitute
Counsel in Pinholster v. Calderon, No. CV 95–6240–GLT
(CD Cal.), p. 2. Relying in part on Pinholster’s abnormal
EEG, Dr. Olson opined that Pinholster’s childhood acci
dents “likely result[ed] in brain injury” and that these
injuries “conferred a risk of epilepsy.” Record ER–699 to
ER–700. He concluded that it was reasonably probable
that Pinholster had suffered from partial epilepsy since at
least 1968 and had suffered from brain injury since at
least 1964. Id., at ER–701.
   Pinholster’s second expert was Dr. Sophia Vinogradov,
associate professor of psychiatry at the University of
California, San Francisco. Dr. Vinogradov’s testimony
was based on essentially the same facts as Dr. Woods’ and
Dr. Stalberg’s state-court declarations. She highlighted
Pinholster’s childhood head traumas, history of epilepsy,
abusive and neglected upbringing, history of substance
abuse, and bizarre behavior on the night of the homicides.
She opined that his aggressive behavior resulted from
childhood head traumas:
    “All data indicates that there were severe effects of
    the two serious head injuries sustained at age 2 and
    age 3, with evidence for behavioral changes related to
    dysfunction of frontal cortex: severe attentional and
    learning problems in childhood, hyperactivity, aggres
    sivity, impulsivity, social-emotional impairment, sei
    zure disorder, and explosive dyscontrol.” Id., at ER–
    731.
She also opined that, right before the homicides, Pinhol
ster was in an “apparently hallucinatory state [that] was
likely the result of his intoxication with multiple sub
stances.” Id., at ER–707
   The State presented two experts: Dr. Stalberg, the
40                    CULLEN v. PINHOLSTER

                      SOTOMAYOR, J., dissenting

psychiatrist who had examined Pinholster in the middle of
trial,28 and Dr. David Rudnick. Although Dr. Stalberg
maintained that Pinholster suffered from antisocial per
sonality disorder, which was his original diagnosis in the
middle of trial, he again emphasized that there was “vo
luminous” and “compelling” mitigation evidence that had
not previously been made available to him or presented to
the jury. Id., at ER–926, ER–953. He stated that conver
sations with Pinholster’s family revealed that he and his
siblings were “raised like animals, wild animals,” id., at
ER–948, and he opined that Pinholster’s upbringing was a
risk factor for antisocial personality disorder. See ibid.
(Pinholster’s upbringing “would speak volumes, looking at
it from a mitigation point of view”). And he agreed that
the mitigation evidence presented at trial was “profoundly
misleading.” Id., at ER–966. Dr. Rudnick testified that
Pinholster suffered from antisocial personality disorder.
   The State also introduced into evidence the 1978 proba
tion report that Pinholster’s counsel had in their posses
sion at the time of his trial. The report demonstrated that
counsel were aware that Pinholster was in classes for
educationally handicapped children, that he was commit
ted to a state hospital for emotionally handicapped chil
dren, and that he suffered two “severe head injuries.” Id.,
at SER–243.
                             B
     Much of the evidence presented at the federal hearing
——————
   28 Before the hearing, Dr. Stalberg had opined that Pinholster was

“substantially impaired by a bipolar mood disorder operating synergis
tically with intoxication and a seizure disorder at the time the crime
was committed.” Record ER–587. At a prehearing deposition, however,
Dr. Stalberg revised his opinion and stated that he continued to believe
that Pinholster suffered from psychopathic personality traits. After the
deposition, Pinholster elected to proceed with a different expert, pre
sumably in light of Dr. Stalberg’s unexpected change in position. The
State then retained Dr. Stalberg as its own expert.
                      Cite as: 563 U. S. ____ (2011)                    41

                       SOTOMAYOR, J., dissenting

was duplicative of the evidence submitted to the California
Supreme Court. The additional evidence presented at the
hearing only confirmed that the California Supreme Court
could not reasonably have rejected Pinholster’s claim.29
   For example, the probation report presented by the
State confirmed that counsel had in their possession in
formation that would have led any reasonable attorney “to
investigate further.” Wiggins, 539 U. S., at 527. Counsel
nevertheless took no action to investigate these leads.
   Pinholster’s experts opined that his childhood head
traumas likely resulted in brain injury and conferred a
risk of epilepsy. Although the State presented testimony
that Pinholster had antisocial personality disorder, it was
not clear error for the District Court to conclude that
jurors could have credited Pinholster’s experts. Even the
——————
  29 The  State argues that the District Court was not entitled to rely on
the evidence adduced at the hearing because Pinholster was not dili
gent in developing his claims in state court and the hearing was there
fore barred by 28 U. S. C. §2254(e)(2). This argument is somewhat
imprecise. Pinholster’s allegations in his amended federal petition
were “identical” to the allegations he presented to the California
Supreme Court, ante, at 6, and he diligently requested a hearing in
state court. The State presumably means to argue that Pinholster’s
new expert testimony changed “the factual basis” of his claim such that,
by the time of the evidentiary hearing, he no longer satisfied
§2254(e)(2). However, at oral argument, the State suggested that
Pinholster was presenting an altogether new claim in the federal court.
See Tr. of Oral Arg. 18. If that is the case, §2254(d)(1) does not apply at
all, and the State should be arguing lack of exhaustion or procedural
default. I do not understand Pinholster to have presented a new claim
to the District Court.
  In any event, Pinholster satisfied §2254(e)(2) in this case. He made
“a reasonable attempt, in light of the information available at the time,
to investigate and pursue claims in state court.” Michael Williams, 529
U. S., at 435. His experts relied on the very same facts and evidence. I
cannot read §2254(e)(2) to impose a strict requirement that petitioners
must use the same experts they presented to the state court. This rule
would result in numerous practical problems, for example in the case of
the unanticipated death of an expert.
42                    CULLEN v. PINHOLSTER

                      SOTOMAYOR, J., dissenting

State’s own expert, Dr. Stalberg, testified to the “volumi
nous” mitigation evidence in Pinholster’s case. Record ER–
926.
  In sum, the evidence confirmed what was already ap
parent from the state-court record: Pinholster’s counsel
failed to conduct an adequate mitigation investigation,
and there was a reasonable probability that at least one
juror confronted with the “voluminous” mitigating evi
dence counsel should have discovered would have voted to
spare Pinholster’s life. Ibid. Accordingly, whether on the
basis of the state- or federal-court record, the courts below
correctly concluded that Pinholster had shown that the
California Supreme Court’s decision reflected an unrea
sonable application of Strickland.30
                        *     *     *
  I cannot agree with either aspect of the Court’s ruling. I
fear the consequences of the Court’s novel interpretation
of §2254(d)(1) for diligent state habeas petitioners with
compelling evidence supporting their claims who were
unable, through no fault of their own, to present that
evidence to the state court that adjudicated their claims.
And the Court’s conclusion that the California Supreme
Court reasonably denied Pinholster’s ineffective
assistance-of-counsel claim overlooks counsel’s failure to
investigate obvious avenues of mitigation and the contrast
between the woefully inadequate mitigation case they
presented and the evidence they should and would have
discovered. I respectfully dissent.

——————
   30 The State’s challenge in this Court is limited to the questions

whether the Federal District Court was entitled to consider the addi
tional evidence in the §2254(d)(1) analysis and whether Pinholster
satisfied §2254(d)(1) on the basis of the state-court record. It has not
challenged the District Court’s ultimate conclusion that Pinholster had
proved that he was “in custody in violation of the Constitution or laws
or treaties of the United States.” §2254(a).
