(Slip Opinion)              OCTOBER TERM, 2014                                       1

                                       Syllabus

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


SUPREME COURT OF THE UNITED STATES

                                       Syllabus

                  BRUMFIELD v. CAIN, WARDEN

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

     No. 13–1433. Argued March 30, 2015 —Decided June 18, 2015
Petitioner Kevan Brumfield was convicted of murder in a Louisiana
  court and sentenced to death before this Court held that the Eighth
  Amendment prohibits execution of the intellectually disabled, Atkins
  v. Virginia, 536 U. S. 304. Implementing Atkins’ mandate, see id., at
  317, the Louisiana Supreme Court determined that an evidentiary
  hearing is required when a defendant “provide[s] objective factors”
  sufficient to raise a “ ‘a reasonable ground’ ” to believe that he has an
  intellectual disability, which the court defined as “(1) subaverage in-
  telligence, as measured by objective standardized IQ tests; (2) signifi-
  cant impairment in several areas of adaptive skills; and (3) manifes-
  tations of this neuro-psychological disorder in the developmental
  stage.” State v. Williams, 2001–1650 (La. 11/1/02), 831 So. 2d 835,
  857, 861, 854.
     Soon after the Williams decision, Brumfield amended his pending
  state postconviction petition to raise an Atkins claim. Seeking an ev-
  identiary hearing, he pointed to evidence introduced at sentencing
  that he had an IQ of 75, had a fourth-grade reading level, had been
  prescribed numerous medications and treated at psychiatric hospitals
  as a child, had been identified as having a learning disability, and
  had been placed in special education classes. The trial court dis-
  missed Brumfield’s petition without holding a hearing or granting
  funds to conduct additional investigation. Brumfield subsequently
  sought federal habeas relief. The District Court found that the state
  court’s rejection of Brumfield’s claim was both “contrary to, or in-
  volved an unreasonable application of clearly established Federal
  law, as determined by” this Court and “based on an unreasonable de-
  termination of the facts in light of the evidence presented in the State
  court proceeding.” 28 U. S. C. §§2254(d)(1), (2). The court went on to
2                        BRUMFIELD v. CAIN

                                Syllabus

    determine that Brumfield was intellectually disabled. The Fifth Cir-
    cuit found that Brumfield’s petition failed to satisfy either of
    §2254(d)’s requirements and reversed.
Held: Because Brumfield satisfied §2254(d)(2)’s requirements, he was
 entitled to have his Atkins claim considered on the merits in federal
 court. Pp. 6–19.
    (a) The two underlying factual determinations on which the state
 trial court’s decision was premised—that Brumfield’s IQ score was
 inconsistent with a diagnosis of intellectual disability and that he
 presented no evidence of adaptive impairment—were unreasonable
 under §2254(d)(2). Because that standard is satisfied, the Court need
 not address §2254(d)(1). Pp. 6–17.
      (1) Expert trial testimony that Brumfield scored a 75 on an IQ
 test is entirely consistent with intellectual disability. Every IQ score
 has a margin of error. Accounting for that margin of error, the
 sources on which the Williams court relied in defining subaverage in-
 telligence describe a score of 75 as consistent with an intellectual dis-
 ability diagnosis. There was no evidence presented to the trial court
 of any other IQ test that was sufficiently rigorous to preclude the
 possibility that Brumfield possessed subaverage intelligence. Pp. 8–
 11.
      (2) The state-court record contains sufficient evidence to suggest
 that Brumfield would meet the criteria for adaptive impairment.
 Under the test most favorable to the State, an individual like Brum-
 field must show a “substantial functional limitation” in three of six
 “areas of major life activity.” Williams, 831 So. 2d, at 854. Brum-
 field—who was placed in special education classes at an early age,
 was suspected of having a learning disability, and can barely read at
 a fourth-grade level—would seem to be deficient in two of those are-
 as: “[u]nderstanding and use of language” and “[l]earning.” Ibid. His
 low birth weight, his commitment to mental health facilities at a
 young age, and officials’ administration of antipsychotic and sedative
 drugs to him at that time all indicate that he may well have had sig-
 nificant deficits in at least one of the remaining four areas. In light
 of that evidence, the fact that the record contains some contrary evi-
 dence cannot be said to foreclose all reasonable doubt as to his intel-
 lectual disability. And given that Brumfield’s trial occurred before
 Atkins, the trial court should have taken into account that the evi-
 dence before it was sought and introduced at a time when Brum-
 field’s intellectual disability was not at issue. Pp. 11–17.
    (b) The State’s two additional arguments are rejected. Because the
 State did not press below the theory that §2254(e)(1) supplies the
 governing standard when evaluating whether a habeas petitioner has
 satisfied §2254(d)(2)’s requirements, that issue is not addressed here.
                     Cite as: 576 U. S. ____ (2015)                   3

                               Syllabus

  And because the state trial court made no finding that Brumfield had
  failed to produce evidence suggesting he could meet the “manifesta-
  tions . . . in the developmental stage” requirement for intellectual
  disability, there is no determination on that point to which a federal
  court must defer in assessing whether Brumfield satisfied §2254(d).
  In any event, the state court record contained ample evidence creat-
  ing a reasonable doubt as to whether Brumfield’s disability manifest-
  ed before adulthood. Pp. 17–18.
744 F. 3d 918, vacated and remanded.

  SOTOMAYOR, J., delivered the opinion of the Court, in which KENNE-
DY,GINSBURG, BREYER, and KAGAN, JJ., joined. THOMAS, J., filed a dis-
senting opinion, in all but Part I–C of which ROBERTS, C. J., and SCALIA
and ALITO, JJ., joined. ALITO, J., filed a dissenting opinion, in which
ROBERTS, C. J., joined.
                        Cite as: 576 U. S. ____ (2015)                              1

                             Opinion of the Court

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


SUPREME COURT OF THE UNITED STATES
                                   _________________

                                   No. 13–1433
                                   _________________


           KEVAN BRUMFIELD, PETITIONER v.

                BURL CAIN, WARDEN

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE FIFTH CIRCUIT

                                 [June 18, 2015] 


  JUSTICE SOTOMAYOR delivered the opinion of the Court.
  In Atkins v. Virginia, 536 U. S. 304 (2002), this Court
recognized that the execution of the intellectually disabled
contravenes the Eighth Amendment’s prohibition on cruel
and unusual punishment. After Atkins was decided,
petitioner, a Louisiana death-row inmate, requested an
opportunity to prove he was intellectually disabled in state
court. Without affording him an evidentiary hearing or
granting him time or funding to secure expert evidence,
the state court rejected petitioner’s claim. That decision,
we hold, was “based on an unreasonable determination of
the facts in light of the evidence presented in the State
court proceeding.” 28 U. S. C. §2254(d)(2). Petitioner was
therefore entitled to have his Atkins claim considered on
the merits in federal court.
                             I
  Petitioner Kevan Brumfield was sentenced to death for
the 1993 murder of off-duty Baton Rouge police officer
Betty Smothers. Brumfield, accompanied by another
individual, shot and killed Officer Smothers while she was
escorting the manager of a grocery store to the bank.
2                        BRUMFIELD v. CAIN

                          Opinion of the Court

   At the time of Brumfield’s trial, this Court’s precedent
permitted the imposition of the death penalty on intellec-
tually disabled persons. See Penry v. Lynaugh, 492 U. S.
302, 340 (1989) (opinion of O’Connor, J.). But in Atkins,
this Court subsequently held that “in light of . . . ‘evolving
standards of decency,’ ” the Eighth Amendment “ ‘places a
substantive restriction on the State’s power to take the
life’ of a mentally retarded offender.” 536 U. S., at 321
(quoting Ford v. Wainwright, 477 U. S. 399, 405 (1986)).1
Acknowledging the “disagreement” regarding how to
“determin[e] which offenders are in fact” intellectually
disabled, the Court left “to the State[s] the task of develop-
ing appropriate ways to enforce the constitutional re-
striction upon [their] execution of sentences.” 536 U. S., at
317 (internal quotation marks omitted; some alterations in
original).
   The Louisiana Supreme Court took up the charge of
implementing Atkins’ mandate in State v. Williams, 2001–
1650 (La. 11/1/02), 831 So. 2d 835. The court held that “a
diagnosis of mental retardation has three distinct compo-
nents: (1) subaverage intelligence, as measured by objec-
tive standardized IQ tests; (2) significant impairment in
several areas of adaptive skills; and (3) manifestations of
this neuro-psychological disorder in the developmental
stage.” Id., at 854 (relying on, inter alia, American Asso-
ciation of Mental Retardation, Mental Retardation: Defini-
tion, Classification, and Systems of Supports (10th ed.
2002) (AAMR), and American Psychiatric Association,
Diagnostic and Statistical Manual of Mental Disorders
(rev. 4th ed. 2000) (DSM–IV)); see also La. Code Crim.
Proc. Ann., Art. 905.5.1(H)(1) (West Cum. Supp. 2015)
(subsequently enacted statute governing Atkins claims
——————
  1 While this Court formerly employed the phrase “mentally retarded,”

we now “us[e] the term ‘intellectual disability’ to describe the identical
phenomenon.” Hall v. Florida, 572 U. S. ___, ___ (2014) (slip op., at 2).
                     Cite as: 576 U. S. ____ (2015)                   3

                         Opinion of the Court

adopting the three Williams criteria). The Williams court
also clarified that “not everyone faced with a death pen-
alty sentence” would “automatically be entitled to a post-
Atkins hearing”; rather, it would “be an individual defend-
ant’s burden to provide objective factors that will put at
issue the fact of mental retardation.” 831 So. 2d, at 857.
Borrowing from the state statutory standard for determin-
ing when a pretrial competency inquiry is necessary, the
court held that an Atkins evidentiary hearing is required
when an inmate has put forward sufficient evidence to
raise a “ ‘reasonable ground’ ” to believe him to be intellec-
tually disabled. See id., at 861; see also id., at 858, n. 33
(characterizing the requisite showing as one raising a
“ ‘reasonable doubt’ ”).2
    Shortly after the Williams decision, Brumfield amended
his pending state postconviction petition to raise an Atkins
claim. He sought an evidentiary hearing on the issue,
asserting that his case was “accompanied by a host of
objective facts which raise the issue of mental retarda-
tion.” App. 203a.
    In support, Brumfield pointed to mitigation evidence
introduced at the sentencing phase of his trial. He focused
on the testimony of three witnesses in particular: his
mother; Dr. Cecile Guin, a social worker who had compiled
a history of Brumfield by consulting available records and
conducting interviews with family members and teachers;
and Dr. John Bolter, a clinical neuropsychologist who had
performed a number of cognitive tests on Brumfield. A
——————
  2 Although   Louisiana subsequently adopted a statute governing the
adjudication of Atkins claims, see La. Code Crim. Proc. Ann., Art.
905.5.1 (West Cum. Supp. 2015), the parties agree that the procedures
set forth in Williams governed this case. See Brief for Petitioner 26,
n. 7; Brief for Respondent 13, n. 6; see also State v. Dunn, 2007–0878
(La. 1/25/08), 974 So. 2d 658, 662 (holding that this statute does not
“establis[ h] a procedure to be used for Atkins hearings conducted post-
trial and/or post-sentencing”).
4                   BRUMFIELD v. CAIN

                     Opinion of the Court

psychologist, Dr. Brian Jordan, had also examined Brum-
field and prepared a report, but did not testify at trial.
Brumfield contended that this evidence showed, among
other things, that he had registered an IQ score of 75, had
a fourth-grade reading level, had been prescribed numer-
ous medications and treated at psychiatric hospitals as a
child, had been identified as having some form of learning
disability, and had been placed in special education classes.
See id., at 203a–204a. Brumfield further requested “all
the resources necessary to the proper presentation of his
case,” asserting that until he was able to “retain the ser-
vices of various experts,” it would be “premature for [the
court] to address [his] claims.” Id., at 207a.
   Without holding an evidentiary hearing or granting
funds to conduct additional investigation, the state trial
court dismissed Brumfield’s petition. With respect to the
request for an Atkins hearing, the court stated:
     “I’ve looked at the application, the response, the rec-
     ord, portions of the transcript on that issue, and the
     evidence presented, including Dr. Bolter’s testimony,
     Dr. Guinn’s [sic] testimony, which refers to and dis-
     cusses Dr. Jordan’s report, and based on those, since
     this issue—there was a lot of testimony by all of those
     in Dr. Jordan’s report.
        “Dr. Bolter in particular found he had an IQ of
     over—or 75. Dr. Jordan actually came up with a little
     bit higher IQ. I do not think that the defendant has
     demonstrated impairment based on the record in
     adaptive skills. The doctor testified that he did have
     an anti-social personality or sociopath, and explained
     it as someone with no conscience, and the defendant
     hadn’t carried his burden placing the claim of mental
     retardation at issue. Therefore, I find he is not enti-
     tled to that hearing based on all of those things that I
     just set out.” App. to Pet. for Cert. 171a–172a.
                 Cite as: 576 U. S. ____ (2015)            5

                     Opinion of the Court

   After the Louisiana Supreme Court summarily denied
his application for a supervisory writ to review the trial
court’s ruling, Brumfield v. State, 2004–0081 (La.
10/29/04), 885 So. 2d 580, Brumfield filed a petition for
habeas corpus in federal court, again pressing his Atkins
claim. Pursuant to the Antiterrorism and Effective Death
Penalty Act of 1996 (AEDPA), Brumfield could secure
relief only if the state court’s rejection of his claim was
either “contrary to, or involved an unreasonable applica-
tion of, clearly established Federal law, as determined by
the Supreme Court of the United States,” or was “based on
an unreasonable determination of the facts in light of the
evidence presented in the State court proceeding.” 28
U. S. C. §§2254(d)(1), (2).
   The District Court found that both of these require-
ments had been met. 854 F. Supp. 2d 366, 383–384 (MD
La. 2012). First, the District Court held that denying
Brumfield an evidentiary hearing without first granting
him funding to develop his Atkins claim “represented an
unreasonable application of then-existing due process
law,” thus satisfying §2254(d)(1). Id., at 379. Second, and
in the alternative, the District Court found that the state
court’s decision denying Brumfield a hearing “suffered
from an unreasonable determination of the facts in light of
the evidence presented in the state habeas proceeding in
violation of §2254(d)(2).” Ibid.
   The District Court further determined Brumfield to be
intellectually disabled based on the extensive evidence it
received during an evidentiary hearing. Id., at 406; see
Cullen v. Pinholster, 563 U. S. 170, ___ (2011) (slip op., at
13) (recognizing that federal habeas courts may “take new
evidence in an evidentiary hearing” when §2254(d) does
not bar relief). This evidence included the results of vari-
ous IQ tests—which, when adjusted to account for meas-
urement errors, indicated that Brumfield had an IQ score
between 65 and 70, 854 F. Supp. 2d, at 392—testimony
6                    BRUMFIELD v. CAIN

                      Opinion of the Court

and expert reports regarding Brumfield’s adaptive behav-
ior and “significantly limited conceptual skills,” id., at 401,
and proof that these deficits in intellectual functioning
had exhibited themselves before Brumfield reached adult-
hood, id., at 405. Thus, the District Court held, Brumfield
had “demonstrated he is mentally retarded as defined by
Louisiana law” and was “ineligible for execution.” Id., at
406.
   The United States Court of Appeals for the Fifth Circuit
reversed. 744 F. 3d 918, 927 (2014). It held that Brum-
field’s federal habeas petition failed to satisfy either of
§2254(d)’s requirements. With respect to the District
Court’s conclusion that the state court had unreasonably
applied clearly established federal law, the Fifth Circuit
rejected the notion that any of this Court’s precedents
required a state court to grant an Atkins claimant the
funds necessary to make a threshold showing of intellec-
tual disability. See 744 F. 3d, at 925–926. As for the
District Court’s holding that the state court’s decision
rested on an unreasonable determination of the facts, the
Fifth Circuit declared that its “review of the record per-
suad[ed it] that the state court did not abuse its discretion
when it denied Brumfield an evidentiary hearing.” Id., at
926. Having found that Brumfield’s petition failed to clear
§2254(d)’s hurdle, the Fifth Circuit did not review the
District Court’s conclusion that Brumfield is, in fact,
intellectually disabled. See id., at 927, and n. 8.
   We granted certiorari on both aspects of the Fifth Cir-
cuit’s §2254(d) analysis, 574 U. S. ___ (2014), and now
vacate its decision and remand for further proceedings.
                             II
   Before this Court, Brumfield advances both of the ra-
tionales on which the District Court relied in holding
§2254(d) to be satisfied. Because we agree that the state
court’s rejection of Brumfield’s request for an Atkins hear-
                     Cite as: 576 U. S. ____ (2015)                   7

                         Opinion of the Court

ing was premised on an “unreasonable determination of
the facts” within the meaning of §2254(d)(2), we need not
address whether its refusal to grant him expert funding,
or at least the opportunity to seek pro bono expert assis-
tance to further his threshold showing, reflected an “un-
reasonable application of . . . clearly established Federal
law,” §2254(d)(1).
   In conducting the §2254(d)(2) inquiry, we, like the
courts below, “look through” the Louisiana Supreme
Court’s summary denial of Brumfield’s petition for review
and evaluate the state trial court’s reasoned decision
refusing to grant Brumfield an Atkins evidentiary hearing.
See Johnson v. Williams, 568 U. S. ___, ___, n. 1 (2013)
(slip op., at 6, n. 1); Ylst v. Nunnemaker, 501 U. S. 797,
806 (1991). Like Brumfield, we do not question the pro-
priety of the legal standard the trial court applied, and
presume that a rule according an evidentiary hearing only
to those capital defendants who raise a “reasonable doubt”
as to their intellectual disability is consistent with our
decision in Atkins. Instead, we train our attention on the
two underlying factual determinations on which the trial
court’s decision was premised—that Brumfield’s IQ score
was inconsistent with a diagnosis of intellectual disability
and that he had presented no evidence of adaptive im-
pairment. App. to Pet. for Cert. 171a–172a.3
——————
  3 The dissent accuses us of “recasting legal determinations as factual

ones.” Post, at 15 (opinion of THOMAS, J.) (emphasis deleted) (hereinaf-
ter the dissent). But we subject these determinations to review under
§2254(d)(2) instead of §2254(d)(1) because we are concerned here not
with the adequacy of the procedures and standards the state court
applied in rejecting Brumfield’s Atkins claim, but with the underlying
factual conclusions the court reached when it determined that the
record evidence was inconsistent with intellectual disability. See
Maggio v. Fulford, 462 U. S. 111, 117 (1983) (per curiam) (reviewing
under the predecessor to §2254(d)(2) the “factual conclusions” underly-
ing a state court’s conclusion that a criminal defendant had raised no
doubt as to his competency to stand trial). We look to Louisiana case
8                       BRUMFIELD v. CAIN

                         Opinion of the Court

   We may not characterize these state-court factual de-
terminations as unreasonable “merely because [we] would
have reached a different conclusion in the first instance.”
Wood v. Allen, 558 U. S. 290, 301 (2010). Instead,
§2254(d)(2) requires that we accord the state trial court
substantial deference. If “ ‘[r]easonable minds reviewing
the record might disagree’ about the finding in question,
‘on habeas review that does not suffice to supersede the
trial court’s . . . determination.’ ” Ibid. (quoting Rice v.
Collins, 546 U. S. 333, 341–342 (2006)). As we have also
observed, however, “[e]ven in the context of federal habeas,
deference does not imply abandonment or abdication of
judicial review,” and “does not by definition preclude
relief.” Miller-El v. Cockrell, 537 U. S. 322, 340 (2003).
Here, our examination of the record before the state court
compels us to conclude that both of its critical factual
determinations were unreasonable.
                             A
  The state trial court’s rejection of Brumfield’s request
for an Atkins hearing rested, first, on Dr. Bolter’s testi-
mony that Brumfield scored 75 on an IQ test and may have
scored higher on another test. See App. to Pet. for Cert.
171a. These scores, the state court apparently believed,
belied the claim that Brumfield was intellectually disabled
because they necessarily precluded any possibility that he
possessed subaverage intelligence—the first of the three
criteria necessary for a finding of intellectual disability.

——————
law only because it provides the framework in which these factual
determinations were made, and makes clear that the state court’s
decision rejecting Brumfield’s Atkins claim was premised on those
determinations. And we apply §2254(d)(2) at the behest of the State
itself, which invokes that provision (and §2254(e)(1)’s similarly fact-
focused standard) in contending that AEDPA bars Brumfield’s Atkins
claim, and characterizes the determinations we review here as “highly
factual.” Brief for Respondent 25.
                     Cite as: 576 U. S. ____ (2015)                    9

                          Opinion of the Court

But in fact, this evidence was entirely consistent with
intellectual disability.
   To qualify as “significantly subaverage in general intel-
lectual functioning” in Louisiana, “one must be more than
two standard deviations below the mean for the test of
intellectual functioning.” Williams, 831 So. 2d, at 853
(internal quotation marks omitted). On the Wechsler
scale for IQ—the scale employed by Dr. Bolter—that
would equate to a score of 70 or less. See id., at 853–854,
n. 26.
   As the Louisiana Supreme Court cautioned in Williams,
however, an IQ test result cannot be assessed in a vac-
uum. In accord with sound statistical methods, the court
explained: “[T]he assessment of intellectual functioning
through the primary reliance on IQ tests must be tem-
pered with attention to possible errors in measurement.”
Ibid. Thus, Williams held, “[a]lthough Louisiana’s defini-
tion of significantly subaverage intellectual functioning
does not specifically use the word ‘approximately,’ because
of the SEM [(standard error of measurement)], any IQ test
score has a margin of error and is only a factor in as-
sessing mental retardation.” Id., at 855, n. 29.
   Accounting for this margin of error, Brumfield’s reported
IQ test result of 75 was squarely in the range of potential
intellectual disability. The sources on which Williams
relied in defining subaverage intelligence both describe a
score of 75 as being consistent with such a diagnosis. See
AAMR, at 59; DSM–IV, at 41–42; see also State v. Dunn,
2001–1635 (La. 5/11/10), 41 So. 3d 454, 470 (“The ranges
associated with the two scores of 75 brush the threshold
score for a mental retardation diagnosis”).4 Relying on
——————
  4 The dissent insists that we have ignored language in Williams es-

tablishing that “the requisite IQ could range ‘from 66 to 74.’ ” Post, at
18 (quoting Williams, 831 So. 2d, at 854, n. 26). But the dissent
wrenches the quoted language out of context. The Williams Court
actually said: “One SEM is plus or minus a specified number of IQ
10                      BRUMFIELD v. CAIN

                         Opinion of the Court

similar authorities, this Court observed in Atkins that “an
IQ between 70 and 75 or lower . . . is typically considered
the cutoff IQ score for the intellectual function prong of
the mental retardation definition.” 536 U. S., at 309, n. 5.
Indeed, in adopting these definitions, the Louisiana Su-
preme Court anticipated our holding in Hall v. Florida,
572 U. S. ___ (2014), that it is unconstitutional to foreclose
“all further exploration of intellectual disability” simply
because a capital defendant is deemed to have an IQ above
70. Id., at ___ (slip op., at 1); see also id., at ___ (slip op.,
at 12) (“For professionals to diagnose—and for the law
then to determine—whether an intellectual disability
exists once the SEM applies and the individual’s IQ score
is 75 or below the inquiry would consider factors indicat-
ing whether the person had deficits in adaptive function-
ing”). To conclude, as the state trial court did, that Brum-
field’s reported IQ score of 75 somehow demonstrated that
he could not possess subaverage intelligence therefore
reflected an unreasonable determination of the facts.
   Nor was there evidence of any higher IQ test score that
could render the state court’s determination reasonable.
The state court claimed that Dr. Jordan, who examined
Brumfield but never testified at trial, “came up with a
little bit higher IQ.” App. to Pet. for Cert. 171a. At trial,
the existence of such a test score was mentioned only
during the cross-examination of Dr. Bolter, who had sim-
ply acknowledged the following: “Dr. Jordan rated his
intelligence just a little higher than I did. But Dr. Jordan
also only did a screening test and I gave a standardized
measure of intellectual functioning.” App. 133a. And in
fact, Dr. Jordan’s written report provides no IQ score. See

——————
points. Thus, an IQ of 70 could range from 66 to 74 assuming an SEM
of 4.” 831 So. 2d, at 854, n. 26. Williams did not thereby hold that an
SEM of 4, and a resultant range of 66 to 74, must be used; it was
simply using this example to illustrate the concept of SEM.
                     Cite as: 576 U. S. ____ (2015)                    11

                          Opinion of the Court

id., at 429a.5 The state court therefore could not reason-
ably infer from this evidence that any examination Dr.
Jordan had performed was sufficiently rigorous to pre-
clude definitively the possibility that Brumfield possessed
subaverage intelligence. See State v. Dunn, 2001–1635
(La. 11/1/02), 831 So. 2d 862, 886, n. 9 (ordering Atkins
evidentiary hearing even though “prison records indi-
cate[d]” the defendant had an “ ‘estimated IQ of 76,’ ” em-
phasizing testimony that prison officials “did not do the
formal IQ testing”).
                               B
  The state court’s refusal to grant Brumfield’s request
for an Atkins evidentiary hearing rested, next, on its con-
clusion that the record failed to raise any question as
to Brumfield’s “impairment . . . in adaptive skills.” App.
to Pet. for Cert. 171a. That determination was also
unreasonable.
  The adaptive impairment prong of an intellectual dis-
ability diagnosis requires an evaluation of the individual’s
ability to function across a variety of dimensions. The
Louisiana Supreme Court in Williams described three
separate sets of criteria that may be utilized in making
this assessment. See 831 So. 2d, at 852–854. Although
Louisiana courts appear to utilize all three of these tests
in evaluating adaptive impairment, see Dunn, 41 So. 3d,
at 458–459, 463, for the sake of simplicity we will assume
that the third of these tests, derived from Louisiana statu-

——————
  5 There  is some question whether Dr. Jordan’s report, which was
introduced in federal habeas proceedings, was ever entered into the
state-court record. See 854 F. Supp. 2d 366, 380, n. 13 (MD La. 2012)
(accepting counsel’s representation that the report was not in the state-
court record); but see Tr. of Oral Arg. 50 (State’s counsel asserting that
it was). We see no need to resolve this dispute, though we note that the
report is not currently contained in the state-court record lodged with
the District Court.
12                        BRUMFIELD v. CAIN

                           Opinion of the Court

tory law, governed here, as it appears to be the most fa-
vorable to the State.6 Under that standard, an individual
may be intellectually disabled if he has “substantial func-
tional limitations in three or more of the following areas of
major life activity: (i) Self-care. (ii) Understanding and use
of language. (iii) Learning. (iv) Mobility. (v) Self-direction.
(vi) Capacity for independent living.” Williams, 831 So.
2d, at 854 (quoting then La. Rev. Stat. Ann. §28:381(12)
(repealed 2005)).
   The record before the state court contained sufficient
evidence to raise a question as to whether Brumfield met
these criteria. During the sentencing hearing, Brumfield’s
mother testified that Brumfield had been born prematurely
at a very low birth weight. App. 28a. She also recounted
that he had been taken out of school in the fifth grade
and hospitalized due to his behavior, and recalled an
incident in which he suffered a seizure. Id., at 34a–38a,
41a, 47a.
   Social worker Dr. Guin elaborated on this testimony,
explaining that Brumfield’s low birth weight indicated
“that something ha[d] gone wrong during the pregnancy,”
that medical records suggested Brumfield had “slower
responses than normal babies,” and that “they knew that
something was wrong at that point.” Id., at 75a–76a. Dr.
Guin also confirmed that, beginning in fifth grade, Brum-
field had been placed in special classes in school and in
multiple mental health facilities, and had been prescribed
——————
   6 The other two standards set forth in Williams were: the AAMR cri-

teria, which require “ ‘limitations in two or more of the following appli-
cable adaptive skill areas: communication, self-care, home living, social
skills, community use, self-direction, health and safety, functional
academics, leisure, and work,’ ” 831 So. 2d, at 852, n. 22; and the DSM–
IV criteria, which similarly require “ ‘significant limitations’ ” in “ ‘at
least two of the following skill areas: communication, self-care, home
living, social/interpersonal skills, use of community resources, self-
direction, functional academic skills, work, leisure, health, and safety,’ ”
id., at 853, n. 25.
                     Cite as: 576 U. S. ____ (2015)                   13

                          Opinion of the Court

antipsychotics and sedatives.      Id., at 89a, 93a–94a.7
Moreover, one report Dr. Guin reviewed from a facility
that treated Brumfield as a child “questioned his intellec-
tual functions,” and opined that “he probably had a learn-
ing disability related to some type of slowness in motor
development, some type of physiological [problem].” Id., at
89a. Dr. Guin herself reached a similar conclusion, stat-
ing that Brumfield “obviously did have a physiologically
linked learning disability that he was born with,” and that
his “basic problem was that he . . . could not process in-
formation.” Id., at 90a, 98a.
   Finally, Dr. Bolter, who had performed “a comprehen-
sive battery of tests,” confirmed that Brumfield had a
“borderline general level of intelligence.” Id., at 127a–
128a. His low intellect manifested itself in a fourth-grade
reading level—and he reached that level, Dr. Bolter elabo-
rated, only with respect to “simple word recognition,” and
“not even comprehension.” Id., at 128a; see also id., at
134a. In a written report submitted to the state court, Dr.
Bolter further noted that Brumfield had deficiencies “fre-
quently seen in individuals with a history of learning
disabilities,” and “clearly” had “learning characteristics
that make it more difficult for him to acquire new infor-
mation.” Id., at 418a, 420a. Dr. Bolter also testified that
Brumfield’s low birth weight had “place[d] him [at] a risk
of some form of potential neurological trauma,” and af-
firmed that the medications administered to Brumfield as
a child were generally reserved for “severe cases.” Id., at
130a, 132a.
   All told, then, the evidence in the state-court record
provided substantial grounds to question Brumfield’s

——————
  7 While   the dissent contends that the record shows Brumfield’s
placement in special education classes was simply due to his misbehav-
ior, post, at 19, Dr. Guin testified that Brumfield’s behavioral problems
were in part a function of a learning disability, see App. 86a.
14                  BRUMFIELD v. CAIN

                     Opinion of the Court

adaptive functioning. An individual, like Brumfield, who
was placed in special education classes at an early age,
was suspected of having a learning disability, and can
barely read at a fourth-grade level, certainly would seem
to be deficient in both “[u]nderstanding and use of lan-
guage” and “[l]earning”—two of the six “areas of major life
activity” identified in Williams. 831 So. 2d, at 854. And
the evidence of his low birth weight, of his commitment to
mental health facilities at a young age, and of officials’
administration of antipsychotic and sedative drugs to him
at that time, all indicate that Brumfield may well have
had significant deficits in at least one of the remaining
four areas. See ibid.
   In advancing its contrary view of the record, the state
court noted that Dr. Bolter had described Brumfield as
someone with “an antisocial personality.” App. 127a; see
App. to Pet. for Cert. 171a. The relevance of this diagnosis
is, however, unclear, as an antisocial personality is not
inconsistent with any of the above-mentioned areas of
adaptive impairment, or with intellectual disability more
generally. The DSM–IV—one of the sources on which the
Williams court relied in defining intellectual disability—
provides: “The diagnostic criteria for Mental Retardation
do not include an exclusion criterion; therefore, the diag-
nosis should be made . . . regardless of and in addition to
the presence of another disorder.” DSM–IV, at 47; see also
AAMR, at 172 (noting that individuals with intellectual
disability also tend to have a number of other mental
health disorders, including personality disorders).
   To be sure, as the dissent emphasizes, post, at 13–14,
18, other evidence in the record before the state court may
have cut against Brumfield’s claim of intellectual disabil-
ity. Perhaps most significant, in his written report Dr.
Bolter stated that Brumfield “appears to be normal from a
neurocognitive perspective,” with a “normal capacity to
learn and acquire information when given the opportunity
                 Cite as: 576 U. S. ____ (2015)           15

                     Opinion of the Court

for repetition,” and “problem solving and reasoning skills”
that were “adequate.” App. 421a. Likewise, the underly-
ing facts of Brumfield’s crime might arguably provide
reason to think that Brumfield possessed certain adaptive
skills, as the murder for which he was convicted required
a degree of advanced planning and involved the acquisi-
tion of a car and guns. But cf. AAMR, at 8 (intellectually
disabled persons may have “strengths in social or physical
capabilities, strengths in some adaptive skill areas, or
strengths in one aspect of an adaptive skill in which they
otherwise show an overall limitation”).
   It is critical to remember, however, that in seeking an
evidentiary hearing, Brumfield was not obligated to show
that he was intellectually disabled, or even that he would
likely be able to prove as much. Rather, Brumfield needed
only to raise a “reasonable doubt” as to his intellectual
disability to be entitled to an evidentiary hearing. See
Williams, 831 So. 2d, at 858, n. 33. The Louisiana Su-
preme Court’s decision in Williams illustrated how low the
threshold for an evidentiary hearing was intended to be:
There, the court held that the defendant was entitled to a
hearing on his Atkins claim notwithstanding the fact that
“the defense’s own expert testified unequivocally, at both
the guilt and penalty phases of trial, that [the] defendant
is not mentally retarded,” an assessment “based on the
fact that [the] defendant [was] not deficient in adaptive
functioning.” 831 So. 2d, at 855; see also Dunn, 831 So.
2d, at 885, 887 (ordering hearing despite expert testimony
that the defendant “had never been identified as a child
who was a slow learner,” and had “received college credit
for courses completed during his incarceration”). Similarly,
in light of the evidence of Brumfield’s deficiencies, none
of the countervailing evidence could be said to foreclose all
reasonable doubt. An individual who points to evidence
that he was at risk of “neurological trauma” at birth, was
diagnosed with a learning disability and placed in special
16                   BRUMFIELD v. CAIN

                      Opinion of the Court

education classes, was committed to mental health facili-
ties and given powerful medication, reads at a fourth-
grade level, and simply cannot “process information,” has
raised substantial reason to believe that he suffers from
adaptive impairments.
   That these facts were alone sufficient to raise a doubt as
to Brumfield’s adaptive impairments is all the more ap-
parent given that Brumfield had not yet had the oppor-
tunity to develop the record for the purpose of proving an
intellectual disability claim. At his pre-Atkins trial,
Brumfield had little reason to investigate or present evi-
dence relating to intellectual disability. In fact, had he
done so at the penalty phase, he ran the risk that it would
“enhance the likelihood . . . future dangerousness [would]
be found by the jury.” Atkins, 536 U. S., at 321. Thus,
given that the evidence from trial provided good reason to
think Brumfield suffered from an intellectual disability,
there was even greater cause to believe he might prove
such a claim in a full evidentiary hearing. Indeed, the
Louisiana Supreme Court had made clear that a capital
defendant in Brumfield’s position should be accorded this
additional benefit of the doubt when it defined the stand-
ard for assessing whether a hearing is required. Echoing
Atkins’ observation that penalty-phase evidence of intel-
lectual disability can be a “two-edged sword,” ibid., Wil-
liams noted that where a trial “was conducted prior to
Atkins,” the defense’s “trial strategy may have been to
shift the focus away from any diagnosis of mental retarda-
tion.” 831 So. 2d, at 856, n. 31. For that reason, the Wil-
liams court considered the fact that the defendant “ha[d]
not had the issue of mental retardation put before the fact
finder in light of the Atkins restriction on the death penalty”
as a factor supporting the requisite threshold showing
that “entitled [him] to an evidentiary hearing.” Id., at
857; accord, Dunn, 831 So. 2d, at 886. Here, the state trial
court should have taken into account that the evidence
                     Cite as: 576 U. S. ____ (2015)                   17

                          Opinion of the Court

before it was sought and introduced at a time when Brum-
field’s intellectual disability was not at issue. The court’s
failure to do so resulted in an unreasonable determination
of the facts.
                              III

                               A

   Urging affirmance of the decision below, the State ad-
vances two additional arguments that we need discuss
only briefly.
   First, the State suggests that rather than being evalu-
ated pursuant to §2254(d)(2)’s “unreasonable determina-
tion of the facts” standard, Brumfield’s attack on the state
trial court’s decision should instead be “ ‘reviewed under
the arguably more deferential standard set out in
§2254(e)(1).’ ” Brief for Respondent 30 (quoting Wood, 558
U. S., at 301).8 We have not yet “defined the precise rela-
tionship between §2254(d)(2) and §2254(e)(1),” Burt v.
Titlow, 571 U. S. ___, ___ (2013) (slip op., at 5), and we
need not do so here. The State did not press below the
theory that §2254(e)(1) supplies the governing standard
when a court evaluates whether a habeas petitioner has
satisfied §2254(d)(2)’s requirements, the Fifth Circuit did
not address that possibility, and the State in its brief in
opposition to certiorari failed to advance any specific
argument that the decision below could be supported by
invocation of that statutory provision. See Brief in Oppo-
sition 60–64. The argument is therefore “properly ‘deemed
waived.’ ” Granite Rock Co. v. Teamsters, 561 U. S. 287,
306 (2010) (quoting this Court’s Rule 15.2).
——————
  8 Section 2254(e)(1) provides: “In a proceeding instituted by an appli-

cation for a writ of habeas corpus by a person in custody pursuant to
the judgment of a State court, a determination of a factual issue made
by a State court shall be presumed to be correct. The applicant shall
have the burden of rebutting the presumption of correctness by clear
and convincing evidence.”
18                  BRUMFIELD v. CAIN

                     Opinion of the Court

   Second, the State contends that Brumfield’s request for
an Atkins hearing was properly rejected because the rec-
ord evidence failed to show that Brumfield’s intellectual
deficiencies manifested while he was in the “developmen-
tal stage”—that is, before he reached adulthood. Wil-
liams, 831 So. 2d, at 854. But the state trial court never
made any finding that Brumfield had failed to produce
evidence suggesting he could meet this age-of-onset re-
quirement. There is thus no determination on that point
to which a federal court must defer in assessing whether
Brumfield satisfied §2254(d). See Panetti v. Quarterman,
551 U. S. 930, 953–954 (2007); compare, e.g., Wiggins v.
Smith, 539 U. S. 510, 534 (2003) (reviewing de novo the
question whether petitioner had suffered prejudice where
state court’s reasoned decision rejecting claim under
Strickland v. Washington, 466 U. S. 668 (1984), was prem-
ised solely on conclusion that attorney’s performance had
not been constitutionally deficient), with Harrington v.
Richter, 562 U. S. 86, 98 (2011) (requiring federal habeas
court to defer to hypothetical reasons state court might
have given for rejecting federal claim where there is no
“opinion explaining the reasons relief has been denied”).
In any event, the state-court record contained ample
evidence creating a reasonable doubt as to whether Brum-
field’s disability manifested before adulthood: Both Dr.
Guin and Dr. Bolter testified at length about Brumfield’s
intellectual shortcomings as a child and their possible
connection to his low birth weight. If Brumfield presented
sufficient evidence to suggest that he was intellectually
limited, as we have made clear he did, there is little ques-
tion that he also established good reason to think that he
had been so since he was a child.
                            B
  Finally, we offer a few additional words in response to
JUSTICE THOMAS’ dissent. We do not deny that Brum-
                 Cite as: 576 U. S. ____ (2015)           19

                     Opinion of the Court

field’s crimes were terrible, causing untold pain for the
victims and their families. But we are called upon today
to resolve a different issue. There has already been one
death that society rightly condemns. The question here is
whether Brumfield cleared AEDPA’s procedural hurdles,
and was thus entitled to a hearing to show that he so
lacked the capacity for self-determination that it would
violate the Eighth Amendment to permit the State to
impose the “law’s most severe sentence,” Hall, 572 U. S.,
at ___ (slip op., at 7), and take his life as well. That
question, and that question alone, we answer in the
affirmative.
                       *     *     *
  We hold that Brumfield has satisfied the requirements
of §2254(d). The judgment of the United States Court of
Appeals for the Fifth Circuit is therefore vacated, and the
case is remanded for further proceedings consistent with
this opinion.
                                            It is so ordered.
                 Cite as: 576 U. S. ____ (2015)            1

                    THOMAS, J., dissenting

SUPREME COURT OF THE UNITED STATES
                         _________________

                         No. 13–1433
                         _________________


         KEVAN BRUMFIELD, PETITIONER v.
              BURL CAIN, WARDEN
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF
            APPEALS FOR THE FIFTH CIRCUIT
                        [June 18, 2015]

  JUSTICE THOMAS, with whom THE CHIEF JUSTICE,
JUSTICE SCALIA, and JUSTICE ALITO join as to all but Part
I–C, dissenting.
  Federal collateral review of state convictions interrupts
the enforcement of state criminal laws and undermines
the finality of state-court judgments. The Antiterrorism
and Effective Death Penalty Act of 1996 (AEDPA) ad-
dresses that interference by constraining the ability of
federal courts to grant relief to state prisoners. Today, the
Court oversteps those limits in a decision that fails to
respect the Louisiana state courts and our precedents. I
respectfully dissent.
                              I
   This case is a study in contrasts. On the one hand, we
have Kevan Brumfield, a man who murdered Louisiana
police officer Betty Smothers and who has spent the last
20 years claiming that his actions were the product of
circumstances beyond his control. On the other hand, we
have Warrick Dunn, the eldest son of Corporal Smothers,
who responded to circumstances beyond his control by
caring for his family, building a professional football ca-
reer, and turning his success on the field into charitable
work off the field.
2                   BRUMFIELD v. CAIN

                    THOMAS, J., dissenting

                             A
   Given that the majority devotes a single sentence to a
description of the crime for which a Louisiana jury sen-
tenced Brumfield to death, I begin there.
   Corporal Smothers, a 14-year veteran of the Baton
Rouge Police Department, was working a second job to
support her family when she was murdered just after
midnight on January 7, 1993. Following a 10-hour shift at
the department on January 6, Corporal Smothers reported
to a local grocery store, where she served as a uniformed
security officer with the official authorization of the de-
partment. She monitored the security of the grocery store
and waited to escort the assistant manager, Kimen Lee, to
a local bank to make the store’s nightly deposit.
   Corporal Smothers followed her usual practice of driving
Lee to the bank in her police cruiser. Shortly after mid-
night, they arrived at the bank’s night depository. As Lee
leaned out of the passenger side door to make the deposit,
she heard the racking of the slide on a handgun. Brum-
field and his accomplice, Henri Broadway, then opened
fire on the two women.
   Brumfield fired seven rounds from a .380-caliber hand-
gun at close range from the left side of the cruiser, while
Broadway fired five rounds from a .25-caliber handgun
from the right rear of the cruiser. Brumfield hit Corporal
Smothers five times in the forearm, chest, and head. Lee
was hit multiple times as well, causing 11 entrance and
exit wounds, but she somehow managed to slide over on
the bench seat and take control of the police car. She
drove to a nearby convenience store, where she was able to
call for help and to describe Broadway to police. Emer-
gency responders transported both women to the hospital.
Corporal Smothers was pronounced dead on arrival. Lee
survived.
   On January 11, 1993, Baton Rouge police arrested
Brumfield for Corporal Smothers’ murder. After several
                     Cite as: 576 U. S. ____ (2015)                     3

                         THOMAS, J., dissenting

hours of police interrogation, during which he denied
involvement in the murder, Brumfield eventually gave a
videotaped confession.1 He admitted that, after riding
around at night looking for a “hustle,” he had come up
with the idea to steal the grocery store’s deposit. He
described how he and Broadway hid in the bushes waiting
for the car to arrive, and how, when Lee looked back while
trying to make the deposit, he started shooting. He admit-
ted that he had fired seven rounds from his .380-caliber
handgun, that Broadway had fired five shots with the .25-
caliber handgun, and that a third man had served as the
getaway driver.
   A Louisiana jury convicted Brumfield of first-degree
murder. In addition to his videotaped confession, the
State introduced evidence that Brumfield had spoken
about committing a robbery to several people in the weeks
leading up to the murder. He was facing sentencing on
unrelated charges and had promised his pregnant girl-
friend that he would obtain money to support her, their
baby, and her child from a previous relationship while he
was in jail. The State also introduced evidence that Brum-
field had told an acquaintance right after the murder that
he had just killed “a son of a bitch.” Record 3566.
                            B
  At the penalty phase, the State sought a death sentence.
It reintroduced the evidence from the guilt phase, along
with evidence of Brumfield’s other criminal acts.2 The
——————
  1 The videotaped confession can be found at http://www.supremecourt.
gov/media/media.aspx.
  2 Although not introduced at trial, it is worth noting that the night of

Corporal Smothers’ murder was apparently not her first interaction
with Brumfield. Six years earlier, she had caught him stealing and had
given him a chance to turn his life around, a chance he unfortunately
did not take. See W. Dunn & D. Yaegar, Running for My Life: My
Journey in the Game of Football and Beyond 12 (2008). As Corporal
Smothers’ eldest son recounted, “[Brumfield] told me a story that in
4                      BRUMFIELD v. CAIN

                       THOMAS, J., dissenting

felony convictions for which Brumfield was awaiting sen-
tencing when he murdered Corporal Smothers were for
attempted possession of cocaine and felony theft of a gun.
Brumfield had worked only three months in his adult life
because, as he had admitted to his psychologist, he found
drug dealing a far more effective way to make money. In
fact, he had been involved a few years earlier in the fatal
shooting of a fellow drug dealer in a deal gone bad. And
10 months after he murdered Corporal Smothers, Brum-
field battered another police officer while in prison.
   The State also explained that Brumfield’s murder of
Corporal Smothers was the culmination of a 2-week crime
spree. On Christmas Day 1992, Brumfield robbed Anthony
Miller at gunpoint after giving him a ride. He forced
Miller out of the car, put a gun to Miller’s head, and pulled
the trigger. Fortunately for Miller, the gun misfired, and
he survived. One week later, Brumfield robbed Edna
Marie Perry and her daughter Trina Perkins at gunpoint
as they were walking along the side of the road. Brum-
field pulled alongside them, pointed a sawed-off shotgun
at Perry, and said, “Hand it over, bitch.” Id., at 3790.
Perry turned over her purse, but pleaded with Brumfield
to give back the pictures from her deceased son’s funeral
that she carried in the purse. He responded none too
courteously, “Bitch, you dead,” and drove away. Ibid.
   The State also introduced evidence about the murder’s
broader impact. In addition to serving as a police officer,
Corporal Smothers was a single mother to six children and
a volunteer coach at a local track club. Her children, who
ranged from 10 to 18 years old, went to live with their
grandmother after the murder. The loss of their mother
——————
1987, my mother, working security at a store, caught him stealing and
made him put back whatever he took. . . . Brumfield said my mom could
have made an example of him that day, but she elected not to. I
thought to myself, that was Mom—always giving people second chances
to do right.” Ibid.
                 Cite as: 576 U. S. ____ (2015)            5

                    THOMAS, J., dissenting

weighed heavily on all of them. It was particularly hard
on Corporal Smothers’ eldest son, Warrick, who had been
especially close to his mother, and on her second eldest
son, Derrick Green, who had been hoping to spend more
time with her after Warrick went off to college. Derrick
was deprived of that chance, and he and Warrick had to
take on extra responsibilities to care for their younger
siblings.
   For his part, Brumfield introduced evidence that his
crimes were “beyond his control,” a product of his disad-
vantaged background. Id., at 3927. He was born at a low
birth weight, and his mother testified that he spent sev-
eral months in the hospital shortly after his birth. His
father left the family, and his stepfather would make him
sit in the corner on hot rice, whip him, and hit him over
the head with a telephone book. His brother eventually
decided to go live with their biological father. Brumfield
opted to stay with his mother and stepfather.
   When he was around seven or eight years old, Brumfield
began to have behavioral problems. He had trouble stay-
ing in his seat at school, was disruptive, easily distracted,
and prone to fighting. He was eventually taken to a psy-
chiatric hospital to address his hyperactivity. Although he
was a straight-A student until the third grade, his time in
four or five group homes educated him in the criminal
lifestyle, and his grades began to suffer.
   Dr. Cecile Guin, a social worker, testified that Brum-
field’s hyperactivity and acting out could be traced largely
to his low birth weight, lack of a supportive home envi-
ronment, and abusive stepfather. Although she was not a
medical doctor, she concluded that Brumfield had a “neu-
rologically based hyperactive or learning disability prob-
lem.” Id., at 3886. She acknowledged, however, that his
school records described him as having a behavior disor-
der—“a pattern situation or inappropriate behavior ex-
tended over a long period of time which cannot be ex-
6                    BRUMFIELD v. CAIN

                     THOMAS, J., dissenting

plained by intellectual, sensory, neurological or other
general factors.” Id., at 3882. She also admitted on cross-
examination that a psychologist, Brian T. Jordan, had not
diagnosed Brumfield as suffering from any neurological
disorder, but instead from “a sociopathic personality dis-
order, antisocial type, poor impulse control, especially in
the area of aggression.” Id., at 3897–3898.
   Dr. John Bolter, a clinical neuropsychologist, testified on
behalf of the defense that Brumfield suffered from an
antisocial personality disorder. Based on a battery of tests
employed to determine whether Brumfield suffered from
“any kind of neurological deficits in cognitive functions,”
Dr. Bolter concluded that Brumfield early on in life “mani-
fest[ed] . . . a conduct disorder with extreme levels of
aggressivity and a disregard for the basic rights of others,”
along with “an attention deficit disorder of some type.”
Id., at 3904. Over time, he “emerged into what looks more
like an antisocial personality,” and he continued to have
“attention difficulty” and “borderline general level of
intelligence.” Ibid. Brumfield’s IQ score was a 75, placing
him at about the seventh percentile of the general popula-
tion or “on the low end of intelligence.” Ibid. His reading
skills were at about a fourth-grade level, while his math
and spelling skills were at about a sixth-grade level. On
the other hand, Dr. Bolter concluded that Brumfield’s
“problem solving, judgment and reasoning skills [we]re
sufficient to meet the demands of everyday adulthood and
he [wa]s not showing any decrement in the types of prob-
lems one would assume to see if they were suffering from
an underlying organic basis or mental illness.” Id., at 275.
Dr. Bolter had also reviewed Dr. Jordan’s report, and he
testified that the only inconsistency in their conclusions
was that Dr. Jordan rated Brumfield’s intelligence “just a
little higher than” he did. Id., at 3907.
   The jury unanimously recommended that Brumfield be
sentenced to death. It found three statutory aggravators
                      Cite as: 576 U. S. ____ (2015)                      7

                          THOMAS, J., dissenting

that made him eligible for that penalty: He was engaged
in the attempted perpetration of an armed robbery; he
knowingly created a risk of death or great bodily harm to
more than one person; and the victim was a peace officer
engaged in her lawful duties. The jury found no statutory
mitigators.
                             C
   Brumfield’s argument that his actions were the product
of his disadvantaged background is striking in light of the
conduct of Corporal Smothers’ children following her
murder. Most widely known is that of Warrick. Though
he had turned 18 just two days before Brumfield murdered
his mother, he quickly stepped into the role of father
figure to his younger siblings.3 In his view, it “was up to
[him] to make sure that everybody grew up to be some-
body.” W. Dunn & D. Yaegar, Running for my Life: My
Journey in the Game of Football and Beyond 37 (2008).
   To that end, Warrick led by example, becoming a star
running back at Florida State University and then in the
National Football League (NFL). During his time at
Florida State, he set records on the field while coping with
the loss of his mother. Id., at 71, 111, 117. Though sepa-
rated from his family in Louisiana, he called his brothers
and sisters regularly,4 sought parenting advice from his
——————
   3 Like Brumfield, Warrick’s father was not a part of his life. Id., at

51. But, unlike Brumfield, Warrick did not use the absence of a father
figure as a justification for murder. Ibid. Instead, he recognized that
his mother had been “the family patriarch” when she was alive, ibid.
and that he had a responsibility to take on that role after her death, id.,
at 37.
   4 In a letter to Brumfield, one of Corporal Smothers’ daughters,

Summer, later wrote: “Can you imagine life at 14 without your mother,
no father to step up and take responsibility for his seed? Not knowing
where your next meal will come from, or where you are going to lay
your head at night, or even who’s going to sacrifice their life to raise six
children because of someone’s selfish acts? Do you know what this can
8                       BRUMFIELD v. CAIN

                        THOMAS, J., dissenting

coach, and returned home when he could. Id., at 111–113.
He kept his mother’s pearl earrings, stained with her
blood from the night she was murdered, in a box on his
dresser. Id., at 71. After four years at Florida State,
Dunn was drafted by the Tampa Bay Buccaneers. Con-
cerned that some of his siblings were struggling in Baton
Rouge, he moved the three youngest into his home in
Tampa Bay. Id., at 139. Although the strain of playing
for the Buccaneers and raising his family weighed on him,
he “accepted it as [his] responsibility . . . to make sure they
stayed on the right path.” Ibid.
  While balancing football and family, Dunn still found
time for others. He started Homes for the Holidays,
a charitable organization that decorates and fully fur-
nishes—down to the toothbrush—homes obtained by single
mothers through first-time homeowner assistance pro-
grams. Dunn was inspired by his own mother, who spent
years working toward the purchase of a home for her
family, but, thanks to Brumfield, did not live to reach her
goal. Id., at 152.
  Dunn’s contributions did not end there. After joining
the Atlanta Falcons in 2002, he expanded the reach of
Homes for the Holidays, id., at 157; traveled overseas to
visit our Armed Forces, id., at 200–201; led an effort to
raise money from the NFL to help respond to the tragic
effects of Hurricane Katrina, id., at 202–205; and became
a founding member of Athletes for Hope, an organization
dedicated to helping athletes find and pursue charitable
opportunities, id., at 207–208. Following his retirement
from professional football in 2008, Dunn launched two
more charitable organizations in honor of his mother:
Betty’s Hope, a mobile bereavement program that offers
no-cost grief counseling services to children in the Baton
——————
[do to] a 14-year-old’s physical, emotional, and mental state of mind?”
Id., at 13 (italics deleted).
                  Cite as: 576 U. S. ____ (2015)            9

                     THOMAS, J., dissenting

Rouge area, and Homes for Service, a program dedicated
to helping service members, police officers, and firefighters
achieve home ownership. As Dunn once remarked, “I
knew that was what my mother would have been most
proud of: not my records, not my awards, but the way I
used my worldly success to give something back.” Id., at
157.
                              D
   Brumfield, meanwhile, has spent the last 20 years
engaged in a ceaseless campaign of review proceedings.
He raised numerous challenges on direct appeal to the
trial court’s discovery orders, admission of evidence, jury
instructions, and preservation of the record; the prosecu-
tor’s references during the penalty phase; and the alleged
deficiencies of his trial counsel. The Louisiana Supreme
Court rejected each of these claims, State v. Brumfield,
96–2667 (La. 10/20/98), 737 So. 2d 660, and this Court
denied his petition for a writ of certiorari, Brumfield v.
Louisiana, 526 U. S. 1025 (1999).
   In 2000, Brumfield filed his first petition for state post-
conviction relief. In that petition, among other things, he
alleged 9 instances of prosecutorial misconduct, over 18
instances of ineffective assistance of counsel, and at least
17 constitutional errors in the jury instructions at the
guilt phase of his trial.
   Brumfield sought and received multiple extensions of
time before finally filing his amended petition for state
postconviction relief in 2003. He raised many of the same
claims as he had in his initial petition, but also asserted
for the first time that he was mentally retarded and there-
fore ineligible for the death penalty under Atkins v. Vir-
ginia, 536 U. S. 304 (2002). In support of that claim, he
alleged that his IQ score was 75, that his reading level
was that of a fourth grader, that he was born prematurely
with a low birth weight and indications of slower responses
10                  BRUMFIELD v. CAIN

                    THOMAS, J., dissenting

than normal babies, that he had suffered seizures and
been prescribed a variety of medications since childhood,
that he was twice treated in psychiatric hospitals during
childhood and adolescence, and that he had been diag-
nosed with a learning disability.
   The state court denied Brumfield’s petition. In a ruling
from the bench, the court explained that not every defend-
ant who requests an evidentiary hearing on an Atkins
claim is entitled to one. Based on its review of “the appli-
cation, the response, the record, portions of the transcript
on that issue, and the evidence presented, including Dr.
Bolter’s testimony, Dr. Guin’s testimony, which refers to
and discusses Dr. Jordan’s report,” App. to Pet. for Cert.
171a, it concluded that Brumfield had not met his burden
to make a threshold showing of mental retardation. In
particular, the court noted that Brumfield had an IQ score
of 75 or higher and had demonstrated no impairment in
adaptive skills. Although Brumfield had requested fees to
develop his Atkins claim, the trial court did not explicitly
rule on the motion, and Brumfield’s counsel did not
prompt him to do so.
   Brumfield then sought federal collateral review. In his
first habeas application, he repeated many of his claims,
including the claim that he is ineligible to be executed
under Atkins. He requested funds to develop that claim in
an evidentiary hearing. The District Court dismissed all
of his claims except for the Atkins one and ordered an
evidentiary hearing. As the majority describes, the Dis-
trict Court eventually granted a writ of habeas corpus. It
concluded that the state court had based its denial of
Brumfield’s Atkins claim on an unreasonable determina-
tion of the facts and had unreasonably applied clearly
established Supreme Court precedent in denying him
funds to develop the claim. The U. S. Court of Appeals for
the Fifth Circuit reversed, concluding that the District
Court should not have conducted an evidentiary hearing
                  Cite as: 576 U. S. ____ (2015)           11

                     THOMAS, J., dissenting

and that AEDPA did not afford relief on either of the
grounds identified by the District Court. 744 F. 3d 918,
926–927 (2014).
                             II
   AEDPA limits “the power of a federal court to grant an
application for a writ of habeas corpus on behalf of a state
prisoner.” Cullen v. Pinholster, 563 U. S. 170, ___ (2011)
(slip op., at 8). As relevant here, 28 U. S. C. §2254(d)
provides that a federal court may not grant an application
    “with respect to any claim that was adjudicated on the
    merits in State court proceedings unless the adjudica-
    tion 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.”
In applying this “highly deferential standard for evaluat-
ing state-court rulings, . . . state-court decisions [must] be
given the benefit of the doubt.” Pinholster, 563 U. S., at
___ (slip op., at 9) (internal quotation marks omitted).
They must be reviewed solely on “the record that was
before the state court that adjudicated the claim on the
merits.” Id., at ___, ___, and n. 7 (slip op., at 9, 12, and
n. 7). And the prisoner must rebut any state court factual
findings he seeks to challenge by clear and convincing
evidence under §2254(e)(1). Burt v. Titlow, 571 U. S. ___,
___ (2013) (slip op., at 5).
   Brumfield presents two grounds for relief under this
framework. First, he argues that the Louisiana state
court denied his Atkins claim based on an unreasonable
12                       BRUMFIELD v. CAIN

                         THOMAS, J., dissenting

determination of the facts, §2254(d)(2).5 Second, he argues
that the Louisiana state court violated clearly established
federal law as determined by this Court when it denied
him funding to develop evidence for that claim,
§2254(d)(1).
                            III
  The majority resolves the case solely on Brumfield’s first
ground, so I begin there.
                              A
   The Louisiana state court’s decision to deny Brumfield’s
Atkins claim was not based on an unreasonable determi-
nation of the facts. “[A] state-court factual determination
is not unreasonable merely because the federal habeas
court would have reached a different conclusion in the
first instance.” Wood v. Allen, 558 U. S. 290, 301 (2010).
Where the record supports a state court’s factual determi-
nations, the prisoner cannot make that showing. See, e.g.,
Titlow, supra, at ___–___ (slip op., at 6–7). Here, the state
court rejected Brumfield’s Atkins claim in an oral ruling as
follows:
     “Dr. Bolter in particular found [Brumfield] had an IQ
     of over—or 75. Dr. Jordan actually came up with a
     little bit higher IQ. I do not think that the defendant
——————
   5 Although this question presented in his petition is framed as one of

law—“[w]hether a state court that considers the evidence presented at
a petitioner’s penalty phase proceeding as determinative of the peti-
tioner’s claim of mental retardation under Atkins v. Virginia, 536 U. S.
304 (2002), has based its decision on an unreasonable determination of
the facts under 28 U. S. C. §2254(d)(2),” Pet. for Cert. i—Brumfield
reframed his question at oral argument as purely one based on the
factual determinations made in his case, Tr. of Oral Arg. 27–28. He
properly conceded that a court does not necessarily make its decision
based on an unreasonable determination of the facts when it rejects an
Atkins claim based on a record developed before Atkins. Tr. of Oral
Arg. 7–8.
                 Cite as: 576 U. S. ____ (2015)           13

                    THOMAS, J., dissenting

    has demonstrated impairment based on the record in
    adaptive skills. The doctor testified that he did have
    an anti-social personality or sociopath, and explained
    it as someone with no conscience, and the defendant
    hadn’t carried his burden [of] placing the claim of
    mental retardation at issue.” App. to Pet. for Cert.
    171a–172a.
That statement contains three factual determinations: (1)
Brumfield’s IQ was at least 75; (2) Brumfield had not
demonstrated impairment in adaptive skills; and (3)
Brumfield has an antisocial personality disorder. Each of
these facts is amply supported by the state-court record.
   To begin, the record justifies a finding that Brumfield’s
IQ is 75, if not a bit higher. Dr. Bolter testified, without
contradiction, that Brumfield scored a 75 on the IQ test he
administered and that “Dr. Jordan rated [Brumfield’s]
intelligence just a little higher than I did.” Record 3907.
Dr. Bolter’s report similarly shows that Brumfield’s test
results were “lower than estimated by Dr. Jordan in Janu-
ary of this year,” but it notes that “Dr. Jordan was using a
screening measure which proves to be less reliable.” Id.,
at 272. The parties dispute whether Dr. Jordan’s report
was made part of the record, but to the extent it was, it
confirms Dr. Bolter’s testimony. Although it does not
specify an IQ score, Dr. Jordan’s report states that Brum-
field’s “intellectual function is slightly limited but gener-
ally close to the Average Range” and that a psychological
test showed him “to be intellectually functioning generally
in the low Average Range.” App. 428a–429a. Because two
thirds of all IQs are expected to lie between 85 and 115, a
fair reading of Dr. Jordan’s statements would suggest an
IQ score closer to 85. See American Association on Mental
Retardation, Mental Retardation: Definition, Classifica-
tion, and Systems of Supports 37 (9th ed. 1992).
   The record likewise supports the state court’s finding
14                  BRUMFIELD v. CAIN

                    THOMAS, J., dissenting

that Brumfield is not impaired in adaptive skills. Under
Atkins, the relevant adaptive skill areas are “ ‘communica-
tion, self-care, home living, social skills, community use,
self-direction, health and safety, functional academics,
leisure, and work.’ ” 536 U. S., at 308, n. 3. Dr. Bolter
reported that Brumfield’s speech was “intelligible and
prosodic” without “evidence of thought derailment,” Rec-
ord 271, and that his writing appeared “normal,” id., at
273. Brumfield lived independently before his arrest,
often staying with his pregnant girlfriend and had been
able to maintain a job for approximately three months
before quitting “because his earnings were better through
distributing drugs and selling firearms.” Id., at 271.
Although Brumfield reads at a fourth-grade level and
spells and performs arithmetic at a sixth-grade level, Dr.
Bolter concluded that he “has a normal capacity to learn
and acquire information when given the opportunity for
repetition.” Id., at 276.
   Finally, the record supports a finding that Brumfield
has an antisocial personality disorder. Dr. Bolter testified,
without contradiction, that what manifested in childhood
as a conduct disorder had developed in adulthood into an
antisocial personality disorder. He described that disorder
as “an absence of a conscience” and “the ability to disre-
gard the rights and feelings of others in favor of what you
want” without any “sense of compunction or remorse.” Id.,
at 3909. Dr. Guin acknowledged that Dr. Jordan had
reached a similar diagnosis. Brumfield presented no
medical evidence disputing it. That the majority disputes
“[t]he relevance of this diagnosis,” ante, at 14, does not
make it any less supported by the record.
   Brumfield thus not only has failed to rebut the state
court’s factual findings by clear and convincing evidence,
§2254(e)(1), he has failed to show that they were anything
other than eminently reasonable. Under any fairminded
application of §2254(d)(2), he would not be entitled to
                     Cite as: 576 U. S. ____ (2015)                   15

                         THOMAS, J., dissenting

relief.
                             B
                              1
   The majority reaches the opposite result with a bit of
legerdemain, recasting legal determinations as factual
ones. It contends that the state court erred in denying
Brumfield’s claim because the evidence Brumfield pre-
sented “was entirely consistent with intellectual disabil-
ity” as defined in Louisiana and thus sufficient to entitle
him to an evidentiary hearing. Ante, at 8–9. That argu-
ment betrays the legal nature of the majority’s dispute
with the state court’s decision: The majority does not—
because it cannot—disagree that each of the state court’s
factual findings was supported by the record. See ante, at
9–10 (not disputing Brumfield’s IQ score); ante, at 14 (not
disputing Brumfield’s diagnosed antisocial personality
disorder); ibid. (acknowledging that “evidence in the rec-
ord before the state court may have cut against Brum-
field’s claim of intellectual disability”); ante, at 15 (ac-
knowledging that “the underlying facts of Brumfield’s
crime might arguably provide reason to think that Brum-
field possessed certain adaptive skills”). Instead, the
majority disagrees with the state court’s conclusion that
Brumfield had not made a sufficient threshold showing of
mental retardation to be entitled to an evidentiary hearing
on his claim. Ante, at 15–16.
   That conclusion, however, is properly characterized as
one based on the application of law to fact, not on the
determination of the facts themselves.6 As we have ex-
——————
  6 The majority attempts to defend its recharacterization of the inquiry

on the ground that the State invoked §2254(d)(2). The State invoked
that provision because that is the basis upon which Brumfield sought
federal collateral relief. But, Brumfield is not entitled to that relief
unless he can show that the state court based its decision to deny his
Atkins claim on unreasonable factual determinations. Rather than
16                      BRUMFIELD v. CAIN

                        THOMAS, J., dissenting

plained, “The question whether a state court errs in de-
termining the facts is a different question from whether it
errs in applying the law.” Rice v. Collins, 546 U. S. 333,
342 (2006). No one can dispute that Brumfield’s IQ score,
adaptive skills, and antisocial personality disorder are
facts. By contrast, the question whether Brumfield has
met the legal standard for relief on, or at least an eviden-
tiary hearing with regard to, his Atkins claim requires the
application of law to those facts. See Panetti v. Quarter-
man, 551 U. S. 930, 948–952 (2007) (applying §2254(d)(1)
to conclude that a state court unreasonably applied clearly
established federal law when it failed to provide a prisoner
with a competency hearing after he made “ ‘a substantial
threshold showing of insanity’ ”).7 Indeed, in discussing
each of these “factual determinations,” the majority turns
first to state law to determine what showing a prisoner
must make to qualify as mentally retarded. Ante, at 9, 11
(citing State v. Williams, 2001–165 (La. 11/1/02), 831
So. 2d 835). If the majority’s disagreement with the state
court’s decision were truly based on “factual determina-
tions,” it is hard to understand what relevance state law
would have.
——————
address those determinations, the majority addresses something else
entirely.
   7 To be sure, the question whether someone is mentally retarded is

one of fact. But that is not the question at issue in an Atkins claim.
Atkins held that a category of mentally retarded offenders could not be
executed consistent with the Eighth Amendment because a national
consensus had developed against such executions. It acknowledged
that there was disagreement about how to define mentally retarded
offenders and clarified that “[n]ot all people who claim to be mentally
retarded will be so impaired as to fall within the range of mentally
retarded offenders about whom there is a national consensus.” 536
U. S., at 317. Thus, when a prisoner brings an Atkins claim, he bears
the burden to establish not just the “fact” of his mental retardation,
but also that he is sufficiently impaired to fall within the category
of persons identified in Atkins as legally beyond a State’s power to
execute.
                     Cite as: 576 U. S. ____ (2015)                    17

                         THOMAS, J., dissenting

                             2
  Even on its own terms, the majority’s so-called “factual”
analysis fails. The majority holds that the record sup-
ported a finding that Brumfield qualified for a hearing on
mental retardation under state law. To reiterate, even if
true, this state-law-based legal analysis cannot overcome
AEDPA’s bar to relief under §2254(d)(2). To make matters
worse, the majority gets the state law wrong.
  The Louisiana Supreme Court’s decision in Williams
instructed state courts to use the statutory standard for
determining when a pretrial competency hearing is neces-
sary—when there is “ ‘reasonable ground to doubt the
defendant’s mental capacity to proceed.’ ” 831 So. 2d, at
858, n. 33 (quoting La. Code Crim. Proc. Ann., Art. 643
(West 2003)).8 It made clear that “reasonable ground to
doubt” is “not a reference to proof beyond a reasonable
doubt in the guilt phase of the trial,” 831 So. 2d, at 858,
n. 33 (emphasis added),9 and that the burden was on the
prisoner to bring forward objective evidence to put his
mental retardation at issue.
  Brumfield’s IQ test score failed to meet the standard for
significantly subaverage intellectual functioning under
Louisiana law. As Williams explained, Louisiana statutes
defined “ ‘significantly subaverage general intellectual
functioning’ ” as “ ‘more than two standard deviations

——————
  8 Itis unclear whether Williams even continued to supply the govern-
ing state law at the time the state court acted, for the Louisiana Legis-
lature had established a procedure for adjudicating claims of mental
retardation in capital cases three months before Brumfield’s hearing.
See 2003 La. Acts p. 698 (enacting La. Code Crim. Proc. Ann., Art.
905.5.1 (West Supp. 2015)). Because that law did not specifically
address the circumstances under which capital defendants would be
entitled to a hearing on such claims, however, I assume for the sake of
argument that Williams supplies the applicable state law.
  9 The majority’s persistent characterization of this standard as a “rea-

sonable doubt” standard is quite misleading. Ante, at 7, 15, 18.
18                       BRUMFIELD v. CAIN

                         THOMAS, J., dissenting

below the mean for the test of intellectual functioning,’ ”
and a person with intellectual functioning two standard
deviations below the mean “would have an IQ of 70 using
the Wechsler scale.” Id., at 853, and n. 26. Accounting for
the standard error of measurement, Williams explained
that the requisite IQ could range “from 66 to 74.” Id., at
854, n. 26.10 The majority prefers to avoid this language,
focusing instead on “[t]he sources on which Williams relied
in defining subaverage intelligence.” Ante, at 9. But the
way to apply a state court’s decision is to apply what the
state court said, and, at 75 and higher, Brumfield’s IQ
scores exceeded the cutoff for significantly subaverage
general intellectual functioning under that decision.
   Brumfield’s evidence of alleged deficits in adaptive skills
similarly failed to meet the requisite standards under
Louisiana law. Williams defined deficits in adaptive skills
as “ ‘substantial functional limitations in three or more of
the following areas of major life activity:’ ” (1) self-care, (2)
understanding and use of language, (3) learning, (4) mobil-
ity, (5) self-direction, and (6) capacity for independent
living. 831 So. 2d, at 853 (quoting then La. Rev. Stat.
Ann. 28:381(12) (repealed 2005)). The only evidence
Brumfield presented that is even potentially relevant to
these factors was evidence of his poor reading skills and
behavioral problems in school. But, once again, Dr. Bolt-
er’s report confirmed that he had “a normal capacity to
learn and acquire information when given the opportunity
for repetition” and that Brumfield’s behavioral problems
——————
  10 Asthe majority points out, the Court in Williams was “using this
example to illustrate the concept of [the standard error of measure-
ment],” ante at 10, n. 4, but it was illustrating the standard error of
measurement as it related to the Louisiana law defining significantly
subaverage general intellectual functioning as “ ‘more than two stand-
ard deviations below the mean for the test of intellectual functioning,’ ”
Williams, supra, at 853, and n. 26 (quoting then La. Rev. Stat. Ann.
28:381(42) (repealed 2005)).
                     Cite as: 576 U. S. ____ (2015)                  19

                        THOMAS, J., dissenting

were attributable to “a conduct disorder that . . . pro-
gressed into an antisocial personality disorder.” Record
276. The majority places special weight on Brumfield’s
placement in “special education” classes, ante, at 4, 13,
n. 7, 14, 15, but the record explains that he was placed in
behavioral disorder classes not because he had a low
capacity to learn, but because he had a high capacity to
make trouble, Record 3846–3847.11 The state court could
reasonably have found that Brumfield had not provided
evidence of “substantial functional limitations” in any of
these categories, let alone the three required by state law.
  Absent objective evidence of either significantly subav-
erage intellectual functioning or deficits in adaptive be-
havior, Brumfield was not entitled to an evidentiary hear-
ing under Williams. The majority’s analysis is erroneous:
It takes a meritless state-law claim, recasts it as two
factual determinations, and then awards relief, despite
ample evidence in the record to support each of the state
court’s actual factual determinations.
                              C
  The majority engages in such maneuvering because
Brumfield argued only that the state court based its deci-
sion to deny his Atkins claim on an unreasonable determi-
nation of the facts, §2254(d)(2), not an unreasonable appli-
cation of clearly established federal law as determined by
this Court, §2254(d)(1). Brumfield, for his part, presented
his claim in this way to avoid AEDPA’s additional re-
strictions on relief for alleged legal errors. As explained
below, overcoming §2254(d)(1)’s bar based on an alleged
——————
  11 The majority places great reliance on the testimony of Dr. Guin,

who was not a medical doctor, that Brumfield’s “out of control behavior”
in the classroom, Record 3879, was a function in part of a learning
disability, ante, at 13. But, Dr. Guin was not qualified to make that
diagnosis, and she acknowledged that the school had diagnosed him
only with a behavioral disorder. Record 3882.
20                   BRUMFIELD v. CAIN

                     THOMAS, J., dissenting

legal error is particularly demanding. Brumfield’s argu-
ments, even if presented properly as legal ones, would not
meet the bar.
   Under §2254(d)(1), a federal court may not award relief
for a claim adjudicated on the merits in state court unless
that adjudication “resulted in a decision that was contrary
to, or involved an unreasonable application of, clearly
established Federal law, as determined by the Supreme
Court of the United States.” “Clearly established Federal
law for purposes of §2254(d)(1) includes only the holdings,
as opposed to the dicta, of this Court’s decisions.” White v.
Woodall, 572 U. S. ___, ___ (2014) (slip op., at 3) (internal
quotation marks and alteration omitted). A state court’s
decision is therefore not “contrary to” our decisions unless
its holding contradicts our holdings, or it “ ‘confronts a set
of facts that are materially indistinguishable from a deci-
sion of this Court and nevertheless arrives at a result
different from our precedent.’ ” Mitchell v. Esparza, 540
U. S. 12, 15–16 (2003) (per curiam). A state court’s deci-
sion is not “ ‘an unreasonable application’ ” of our decisions
if it merely “ ‘decline[s] to apply a specific legal rule that
has not been squarely established by this Court.’ ” Har-
rington v. Richter, 562 U. S. 86, 101 (2011). Instead, the
Court must evaluate the application of our holdings in the
context of the rule’s specificity: “The more general the
rule, the more leeway courts have in reaching outcomes in
case-by-case determinations.” Ibid. (internal quotation
mark omitted). “[W]here the precise contours of [a] right
remain unclear, state courts enjoy broad discretion in
their adjudication of a prisoner’s claims.” Woodall, supra,
at ___ (slip op., at 9) (internal quotation marks omitted).
   “If this standard is difficult to meet, that is because it
was meant to be.” Richter, 562 U. S., at 102. “ ‘Federal
habeas review of state convictions . . . disturbs the State’s
significant interest in repose for concluded litigation,
denies society the right to punish some admitted offend-
                  Cite as: 576 U. S. ____ (2015)            21

                     THOMAS, J., dissenting

ers, and intrudes on state sovereignty to a degree matched
by few exercises of federal judicial authority.’ ” Id., at 103.
Although AEDPA “stops short of imposing a complete bar”
on this type of review, it does require “a state prisoner [to]
show that the state court’s ruling on the claim being pre-
sented in federal court was so lacking in justification that
there was an error well understood and comprehended in
existing law beyond any possibility for fairminded disa-
greement.” Id., at 102–103. Brumfield cannot meet this
standard.
                              1
   The state court’s decision to deny Brumfield’s Atkins
claim was not contrary to any holding of this Court. The
state court recognized that Atkins precludes the execution
of mentally retarded offenders and then concluded that
Brumfield did not qualify as a mentally retarded offender.
Because this Court has never confronted a set of facts that
are materially indistinguishable from the facts in this case
and arrived at a different result, the state court’s decision
was not “contrary to” clearly established federal law as
determined by this Court.
   Nor is the decision of the state court to deny a hearing
on the claim contrary to such clearly established law. In
Atkins, this Court held that the Eighth Amendment pre-
cludes the execution of mentally retarded offenders, but
“le[ft] to the States the task of developing appropriate
ways to enforce the constitutional restrictions upon their
execution of sentences.” 536 U. S., at 317 (internal quota-
tion mark and brackets omitted). This Court did not so
much as mention an evidentiary hearing, let alone hold
that prisoners raising Atkins claims are entitled to one.
To be sure, Atkins cited this Court’s decision in Ford v.
Wainwright, 477 U. S. 399 (1986), when it explained that
it was leaving the enforcement of the right to the States.
See 536 U. S., at 316–317. Justice Powell’s controlling
22                  BRUMFIELD v. CAIN

                    THOMAS, J., dissenting

concurrence in Ford required a court to afford a prisoner a
hearing on the claim that he is insane and therefore ineli-
gible to be executed after a prisoner made a “substantial
threshold showing of insanity.” 477 U. S., at 426 (opinion
concurring in part and concurring in judgment). The
citation in Atkins, however, not only was not to that por-
tion of Ford, it was not even to Justice Powell’s opinion in
Ford. Compare Atkins, supra, at 317 (citing Ford, supra,
at 405 (majority opinion), 416–417 (opinion of Marshall,
J.)), with Ford, supra, at 426 (opinion of Powell, J.). At-
kins thus did not imply—let alone hold—that a prisoner is
entitled to a hearing on an Atkins claim. There being no
mention of a hearing, the state court’s decision to deny
Brumfield such a hearing could not be “contrary to . . .
clearly established Federal law.” §2254(d)(1).
   Even if Atkins did establish a right to an evidentiary
hearing upon a threshold showing of mental retardation,
the state court’s decision to deny Brumfield a hearing
would not be contrary to that rule. After all, the state
court took the position that Brumfield would have been
entitled to an evidentiary hearing if he had made a
threshold showing of mental retardation; it simply con-
cluded that he had not made that showing. This Court
has never confronted a set of materially indistinguishable
facts and found the threshold showing satisfied. Thus, as
with its rejection of the Atkins claim itself, the state
court’s decision to deny Brumfield an Atkins hearing was
not contrary to clearly established federal law as deter-
mined by this Court.
                            2
  The state court’s decision here likewise was not an
unreasonable application of Atkins. The Atkins Court did
not clearly define the category “of mentally retarded of-
fenders about whom there is a national consensus.” 536
U. S., at 317. It offered guidance in the form of several
                  Cite as: 576 U. S. ____ (2015)            23

                     THOMAS, J., dissenting

clinical definitions of mental retardation as “ ‘subaverage
intellectual functioning’ ” accompanied by “significant
limitations in adaptive skills such as communication, self-
care, and self-direction that became manifest before age
18.” Id., at 318. It gave conflicting indications of the IQ
score necessary for “subaverage intellectual functioning,”
defining mild mental retardation as the term used to de-
scribe “people with an IQ level of 50–55 to approximately
70,” id., at 308, n. 3; and citing one source that reports
70 or less as the statistical criterion for mental retarda-
tion, id., at 309, n. 5; see 2 Kaplan & Sadock’s Compre-
hensive Textbook of Psychiatry 2589 (B. Sadock & V.
Sadock eds., 7th ed. 2000); but commenting that “an IQ
between 70 and 75 or lower . . . is typically considered the
cutoff IQ score for the intellectual function prong of the
mental retardation definition,” 536 U. S., at 309, n. 5. It
offered no greater specificity with respect to “significant
limitations in adaptive skills,” though it remarked that,
“by definition,” mentally retarded offenders “have dimin-
ished capacities to understand and process information, to
communicate, to abstract from mistakes and learn from
experience, to engage in logical reasoning, to control im-
pulses, and to understand the reactions of others.” Id., at
318.
   The state court here reasonably applied the general rule
announced in Atkins when it rejected Brumfield’s claim.
Brumfield achieved a 75 on the IQ test administered to
him by Dr. Bolter, 5 points above the score identified by
Atkins as the upper end of “ ‘[m]ild’ ” mental retardation,
id., at 308, n. 3, and by clinical definitions as the criterion
for mental retardation. He also scored somewhat higher
on the IQ tests administered to him by Dr. Jordan. In
addition, he demonstrated no impairment in adaptive
skills. To the contrary, his test results “indicate[d] that
his problem solving, judgment and reasoning skills are
sufficient to meet the demands of everyday adulthood and
24                       BRUMFIELD v. CAIN

                         THOMAS, J., dissenting

he is not showing any decrement in the types of problems
one would assume to see if they were suffering from an
underlying organic basis or mental illness.” Record 275.
Based on this record, the state court reasonably concluded
that Brumfield had not come forward with evidence that
he fell within the category of mentally retarded offenders
about whom a national consensus against execution had
developed.
  For the same reasons, even if one were to mischaracter-
ize Atkins as clearly establishing a right to an evidentiary
hearing upon a substantial threshold showing of mental
retardation, the state court did not unreasonably apply
that rule. Atkins did not define the showing necessary,
and the state court reasonably concluded that, on this
record, Brumfield had not met it.12
                              D
  In sum, §2254(d) bars Brumfield’s Atkins claim. The
facts upon which the state court rejected his claim are
amply supported by the record and thus not unreasonable.
In concluding otherwise, the majority conflates questions
of fact with questions about the application of law to fact.
That conflation may help it get around the inconveniences
of “clearly established Federal law as determined by th[is
Court],” §2254(d)(1), but it does violence to the statute and
to our ordinary understanding of “facts.” Indeed, we have
summarily reversed lower courts for making that same
error. See, e.g., Lopez v. Smith, 574 U. S. ___, ___ (2014)
——————
  12 It is worth reiterating that the majority’s analysis of state law

would afford no basis for relief under §2254(d)(1), even if Brumfield had
requested relief under that provision. Section 2254(d)(1) serves as a
basis for relief only when a state court reached a decision that involved
an “unreasonable application of . . . clearly established Federal law, as
determined by [this] Court.” (Emphasis added.) And even if Brumfield
could show a violation of state law, which he cannot for the reasons I
discussed above, such a violation would “provide no basis for federal
habeas relief.” Estelle v. McGuire, 502 U. S. 62, 68, n. 2. (1991).
                  Cite as: 576 U. S. ____ (2015)           25

                     THOMAS, J., dissenting

(per curiam) (slip op., at 8) (“Although the Ninth Circuit
claimed its disagreement with the state court was factual
in nature, in reality its grant of relief was based on a legal
conclusion about the adequacy of the notice provided”).
We should hold ourselves to the same standard.
                             IV
   The majority’s willingness to afford relief on Brumfield’s
first ground of alleged error in the state court’s dismissal
of his Atkins claim obviates its need to resolve his second,
which focuses on the state court’s denial of funding to
develop that claim.      Because I would conclude that
AEDPA bars relief on the first ground, I must also address
the second. AEDPA’s standards make short work of that
ground as well.
   The state court’s denial of funding to Brumfield was
neither contrary to, nor an unreasonable application of,
clearly established federal law as determined by this
Court. No precedent of this Court addresses whether and
under what circumstances a state prisoner must be af-
forded funds to develop an Atkins claim. Atkins left “to the
States the task of developing appropriate ways to enforce
the constitutional restriction upon their execution of sen-
tences.” 536 U. S., at 317 (internal quotation marks and
brackets omitted). None of our decisions since Atkins have
even purported to address constitutional requirements for
funding of these claims.
   Brumfield believes that the decision was contrary to,
and involved an unreasonable application of Ake v. Okla-
homa, 470 U. S. 68 (1985), and Ford v. Wainwright, 477
U. S. 399, but neither of those decisions even involved
protections for mentally retarded offenders. Instead, both
decisions addressed protections for prisoners asserting
insanity—Ake in the context of insanity as a defense to a
crime, 470 U. S., at 70, 77, and Ford in the context of
insanity as a limitation on the State’s power to execute a
26                  BRUMFIELD v. CAIN

                    THOMAS, J., dissenting

prisoner, 477 U. S., at 418 (Powell, J., concurring in part
and concurring in judgment). Neither involved the ques-
tion whether a prisoner is entitled to funds to develop an
insanity claim before he has made a substantial threshold
showing of that claim. Only Ake addressed the question of
funds at all, and it held that an indigent defendant has a
right of “access” to a competent psychiatrist to assist in
the preparation of his insanity defense, not that an “indi-
gent defendant has a constitutional right to choose a
psychiatrist of his personal liking or to receive funds to
hire his own.” 470 U. S., at 83.
   The state court fully complied with this Court’s deci-
sions when it declined to award Brumfield funds. Brum-
field did not meet his burden to make a substantial
threshold showing of mental retardation. No decision of
this Court requires a State to afford a defendant funds to
do so.
                        *     *    *
   Over 20 years ago, Brumfield deprived the people of
Baton Rouge of one of their police officers and six children
of their mother. A jury of his peers found Brumfield guilty
of the crime and sentenced him to death. The Louisiana
courts afforded him full appellate and collateral-review
proceedings.
   Today, the majority tosses those proceedings aside,
concluding that the state court based its decision to deny
Brumfield’s Atkins claim on an “unreasonable determina-
tion of the facts,” even as it concedes that the record in-
cludes evidence supporting that court’s factual findings.
Under AEDPA, that concession should bar relief for Brum-
field. In concluding otherwise, the majority distorts fed-
eral law and intrudes upon Louisiana’s sovereign right to
enforce its criminal laws and its courts’ judgments. Such
willfulness is disheartening.
   What is perhaps more disheartening than the majority’s
                Cite as: 576 U. S. ____ (2015)         27

                   THOMAS, J., dissenting

disregard for both AEDPA and our precedents is its disre-
gard for the human cost of its decision. It spares not a
thought for the 20 years of judicial proceedings that its
decision so casually extends. It spares no more than a
sentence to describe the crime for which a Louisiana jury
sentenced Brumfield to death. It barely spares the two
words necessary to identify Brumfield’s victim, Betty
Smothers, by name. She and her family—not to mention
our legal system—deserve better.
  I respectfully dissent.
28                BRUMFIELD v. CAIN

                 THOMAS
             Appendix     , J., dissenting
                      to opinion   of THOMAS, J.

                      APPENDIX




W. Dunn & D. Yaeger, Running for My Life: My Journey
in the Game of Football and Beyond (2008).
                 Cite as: 576 U. S. ____ (2015)            1

                     ALITO, J., dissenting

SUPREME COURT OF THE UNITED STATES
                         _________________

                         No. 13–1433
                         _________________


         KEVAN BRUMFIELD, PETITIONER v.

              BURL CAIN, WARDEN

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE FIFTH CIRCUIT

                        [June 18, 2015] 


  JUSTICE ALITO, with whom THE CHIEF JUSTICE joins,
dissenting.
  I join all but Part I–C of JUSTICE THOMAS’ dissent. The
story recounted in that Part is inspiring and will serve a
very beneficial purpose if widely read, but I do not want to
suggest that it is essential to the legal analysis in this
case.
