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SUPREME COURT OF THE UNITED STATES
BOBBY JAMES MOORE, PETITIONER v.
on writ of certiorari to the court of criminal
appeals of texas
[March 28, 2017]
Justice Ginsburg delivered the opinion of the
Bobby James Moore fatally shot a store clerk
during a botched robbery. He was convicted of capital murder and
sentenced to death. Moore challenged his death sentence on the
ground that he was intellectually disabled and therefore exempt
from execution. A state habeas court made detailed factfindings and
determined that, under this Court’s decisions in
, 536 U. S. 304 (2002) , and
, 572 U. S. ___ (2014), Moore
qualified as intellectually disabled. For that reason, the court
concluded, Moore’s death sentence violated the Eighth
Amendment’s proscription of “cruel and unusual
punishments.” The habeas court therefore recommended that
Moore be granted relief.
The Texas Court of Criminal Appeals
] declined to adopt the
judgment recommended by the state habeas court.[2
] In the CCA’s view, the habeas court
erroneously employed intellectual-disability guides currently used
in the medical community rather than the 1992 guides adopted by the
CCA in Ex parte Briseno
, 135 S. W. 3d 1
(2004). See Ex parte Moore
, 470 S. W. 3d 481,
486–487 (2015). The appeals court further determined that the
evidentiary factors announced in Briseno
heavily” against upsetting Moore’s death sentence. 470
S. W. 3d, at 526.
We vacate the CCA’s judgment. As we
instructed in Hall
, adjudications of intellectual disability
should be “informed by the views of medical experts.”
572 U. S., at ___ (slip op., at 19); see id.
, at ___
(slip op., at 7). That instruction cannot sensibly be read to give
courts leave to diminish the force of the medical community’s
consensus. Moreover, the several factors Briseno
set out as
indicators of intellectual disability are an invention of the CCA
untied to any acknowledged source. Not aligned with the medical
community’s information, and drawing no strength from our
precedent, the Briseno
factors “creat[e] an
unacceptable risk that persons with intellectual dis-ability will
be executed,” 572 U. S., at ___ (slip op., at 1).
Accordingly, they may not be used, as the CCA used them, to
restrict qualification of an individual as intellectually
In April 1980, then-20-year-old Bobby James
Moore and two others were engaged in robbing a grocery store.
Ex parte Moore
, 470 S. W. 3d 481,
490–491 (Tex. Crim. App. 2015); App. 58. During the episode,
Moore fatally shot a store clerk. 470 S. W. 3d, at 490.
Some two months later, Moore was convicted and sentenced to death.
, at 492. A federal habeas court later vacated that
sentence based on ineffective assistance of trial counsel, see
, 1995 U. S. Dist. LEXIS 22859,
*35 (SD Tex., Sept. 29, 1995), and the Fifth Circuit affirmed, see
, 194 F. 3d 586, 622 (1999).
Moore was resentenced to death in 2001, and the CCA affirmed on
direct appeal. See Moore
, 2004 WL 231323, *1
(Jan. 14, 2004), cert. denied, 543 U. S. 931 (2004) .
Moore subsequently sought state habeas relief.
In 2014, the state habeas court conducted a two-day hearing on
whether Moore was intellectually disabled. See Ex parte
, No. 314483–C (185th Jud. Dist., Harris Cty., Tex.,
Feb. 6, 2015), App. to Pet. for Cert. 129a. The court received
affidavits and heard testimony from Moore’s family members,
former counsel, and a number of court-appointed mental-health
experts. The evidence revealed that Moore had significant mental
and social difficulties beginning at an early age. At 13, Moore
lacked basic understanding of the days of the week, the months of
the year, and the seasons; he could scarcely tell time or
comprehend the standards of measure or the basic principle that
subtraction is the reverse of addition. Id.
, at 187a. At
school, because of his limited ability to read and write, Moore
could not keep up with lessons. Id.
, at 146a,
182a–183a. Often, he was separated from the rest of the class
and told to draw pictures. Ibid.
teachers, and peers called him “stupid” for his slow
reading and speech. Id.
, at 146a, 183a. After failing every
subject in the ninth grade, Moore dropped out of high school.
, at 188a. Cast out of his home, he survived on the
streets, eating from trash cans, even after two bouts of food
, at 192a–193a.
In evaluating Moore’s assertion of
intellectual disability, the state habeas court consulted current
medical diagnostic standards, relying on the 11th edition of the
American Association on Intellectual and Developmental Disabilities
(AAIDD) clinical manual, see AAIDD, Intellectual Disability:
Definition, Classification, and Systems of Supports (2010)
(hereinafter AAIDD–11), and on the 5th edition of the
Diagnostic and Statistical Manual of Mental Disorders published by
the American Psychiatric Association (APA), see APA, Diagnostic and
Statistical Manual of Mental Disorders (2013) (hereinafter
DSM–5). App. to Pet. for Cert. 150a–151a, 202a. The
court followed the generally accepted, uncontroversial
intellectual-disability diagnos-tic definition, which identifies
three core elements: (1) intellectual-functioning deficits
(indicated by an IQ score “approximately two standard
deviations below the mean”—i.e.
, a score of
roughly 70—adjusted for “the standard error of
measurement,” AAIDD–11, at 27); (2) adaptive deficits
(“the inability to learn basic skills and adjust behavior to
changing circumstances,” Hall
U. S. ___, ___ (2014) (slip op., at 8)); and (3) the onset of
these deficits while still a minor. See App. to Pet. for Cert. 150a
(citing AAIDD–11, at 1). See also Hall
, 572 U. S., at
___ (slip op., at 8).[3
Moore’s IQ scores, the habeas court
determined, established subaverage intellectual functioning. The
court credited six of Moore’s IQ scores, the average of which
(70.66) indicated mild intellectual disability. App. to Pet. for
relying on testimony from several mental-health experts, the habeas
court found significant adaptive deficits. In determining the
significance of adaptive deficits, clinicians look to whether an
individual’s adaptive performance falls two or more standard
deviations below the mean in any of the three adaptive skill sets
(conceptual, social, and practical). See AAIDD–11, at 43.
Moore’s performance fell roughly two standard deviations
below the mean in all three
skill categories. App. to Pet.
for Cert. 200a–201a. Based on this evidence, the state habeas
court recommended that the CCA reduce Moore’s sentence to
life in prison or grant him a new trial on intellectual disability.
, at 203a.
The CCA rejected the habeas court’s
recommendations and denied Moore habeas relief. See 470
S. W. 3d 481. At the outset of its opinion, the CCA
reaffirmed Ex parte Briseno
, 135 S. W. 3d 1 (Tex. Crim.
App. 2004), as paramount precedent on intellectual disability in
Texas capital cases. See 470 S. W. 3d, at 486–487.
adopted the definition of, and standards for
assessing, intellectual disability contained in the 1992 (ninth)
edition of the American Association on Mental Retardation (AAMR)
manual, predecessor to the current AAIDD–11 manual. See 135
S. W. 3d, at 7 (citing AAMR, Mental Retardation:
Definition, Classification, and Systems of Supports (9th ed. 1992)
AAMR–9’s requirement that adaptive deficits be
“related” to intellectual-functioning deficits. 135
S. W. 3d, at 7 (quoting AAMR–9, at 25).[5
] To determine whether a defendant has
satisfied the relatedness requirement, the CCA instructed in this
case, Texas courts should attend to the “seven evidentiary
factors” first set out in Briseno
S. W. 3d, at 489.[6
No citation to any authority, medical or judicial, accompanied the
court’s recitation of the seven factors. See
135 S. W. 3d, at 8–9.
The habeas judge erred, the CCA held, by
“us[ing] the most current position, as espoused by AAIDD,
regarding the diagnosis of intellectual disability rather than the
test . . . in Briseno
S. W. 3d, at 486. This Court’s decision in
, 536 U. S. 304 (2002) , the
CCA emphasized, “left it to the States to develop appropriate
ways to enforce the constitutional restriction” on the
execution of the intellectually disabled. 470 S. W. 3d,
at 486. Thus, even though “[i]t may be true that the
AAIDD’s and APA’s positions regarding the diagnosis of
intellectual disability have changed since Atkins
,” the CCA retained Briseno
instructions, both because of “the subjectivity surrounding
the medical diagnosis of intellectual disability” and because
the Texas Legislature had not displaced Briseno
other guideposts. 470 S. W. 3d, at 486–487. The
inquiries, the court said, “remai[n]
adequately ‘informed by the medical community’s
diagnostic framework.’ ” 470 S. W. 3d,
at 487 (quoting Hall
, 572 U. S., at ___ (slip op., at
, the CCA first
determined that Moore had failed to prove significantly subaverage
intellectual functioning. 470 S. W. 3d, at 514–519.
Rejecting as unreliable five of the seven IQ tests the habeas court
had considered, the CCA limited its appraisal to Moore’s
scores of 78 in 1973 and 74 in 1989. Id.
, at 518–519.
The court then discounted the lower end of the standard-error range
associated with those scores. Id.
, at 519; see infra
at 10–11 (describing standard error of measurement).
Regarding the score of 74, the court observed that Moore’s
history of academic failure, and the fact that he took the test
while “exhibit[ing] withdrawn and depressive behavior”
on death row, might have hindered his performance. 470
S. W. 3d, at 519. Based on the two scores, but not on the
lower portion of their ranges, the court concluded that
Moore’s scores ranked “above the intellectually
disabled range” (i.e.
, above 70). Ibid.
, at 513.
“Even if [Moore] had proven that he
suffers from significantly sub-average general intellectual
functioning,” the court continued, he failed to prove
“significant and related limitations in adaptive
, at 520. True, the court
acknowledged, Moore’s and the State’s experts agreed
that Moore’s adaptive-functioning test scores fell more than
two standard deviations below the mean. Id.
, at 521; see
, at 4. But the State’s expert ultimately
discounted those test results because Moore had “no
exposure” to certain tasks the testing included, “such
as writing a check and using a microwave oven.” 470
S. W. 3d, at 521–522. Instead, the expert
emphasized Moore’s adaptive strengths in school, at trial,
and in prison. Id.
, at 522–524.
The CCA credited the state expert’s
, at 524. The habeas court, the CCA concluded,
had erred by concentrating on Moore’s adaptive weaknesses.
, at 489. Moore had demonstrated adaptive strengths, the
CCA spelled out, by living on the streets, playing pool and mowing
lawns for money, committing the crime in a sophisticated way and
then fleeing, testifying and representing himself at trial, and
developing skills in prison. Id.
, at 522–523. Those
strengths, the court reasoned, undercut the significance of
Moore’s adaptive limitations. Id.
The habeas court had further erred, the CCA
determined, by failing to consider whether any of Moore’s
adaptive deficits were related to causes other than his
intellectual-functioning deficits. Id.
, at 488, 526. Among
alterna-tive causes for Moore’s adaptive deficits, the CCA
suggested, were an abuse-filled childhood, undiagnosed learning
disorders, multiple elementary-school transfers, racially motivated
harassment and violence at school, and a his-tory of academic
failure, drug abuse, and absenteeism. Ibid.
significant improvement in prison, in the CCA’s view,
confirmed that his academic and social difficulties were not
related to intellectual-functioning deficits. Ibid.
court then examined each of the seven Briseno
factors, see supra
, at 5–6, and n. 6, concluding
that those factors “weigh[ed] heavily” against finding
that Moore had satisfied the relatedness requirement. 470
S. W. 3d, at 526–527.
Judge Alcala dissented. Atkins
, she would have held, require courts to consult current
medical standards to determine intellectual disability. 470
S. W. 3d, at 530. She criticized the majority for relying
on manuals superseded in the medical community, id.
530–534, 536–539, and for disregarding the habeas
court’s credibility determinations, id.
535–536, 538–539. Judge Alcala questioned the
legitimacy of the seven Briseno
factors, recounting wide
criticism of the factors and explaining how they deviate from the
current medical consensus. See 470 S. W. 3d, at
529–530, and n. 5. Most emphatically, she urged, the CCA
“must consult the medical community’s current views and
standards in determining whether a defendant is intellectually
disabled”; “reliance on . . . standard[s] no
longer employed by the medical community,” she objected,
“is constitutionally unaccept-able.” Id.
We granted certiorari to determine whether the
CCA’s adherence to superseded medical standards and its
reliance on Briseno
comply with the Eighth Amendment and
this Court’s precedents. 578 U. S. ___ (2016).
The Eighth Amendment prohibits “cruel
and unusual punishments,” and “reaffirms the duty of
the government to respect the dignity of all persons,”
, 572 U. S., at ___ (slip op., at 5) (quoting
, 543 U. S. 551, 560 (2005) ).
“To enforce the Constitution’s protection of human
dignity,” we “loo[k] to the evolving standards of
decency that mark the progress of a maturing society,”
recognizing that “[t]he Eighth Amendment is not fastened to
the obsolete.” Hall
, 572 U. S., at ___ (slip op.,
at 5) (internal quotation marks omitted).
, we held
that the Constitution “restrict[s] . . . the
State’s power to take the life of” any
intellectually disabled individual. 536 U. S., at 321. See
, 572 U. S., at ___ (slip op., at 6);
, 543 U. S., at 563–564. Executing
intellectually disabled individuals, we concluded in Atkins
serves no penological purpose, see 536 U. S., at
318–320; runs up against a national consensus against the
practice, see id.
, at 313–317; and creates a
“risk that the death penalty will be imposed in spite of
factors which may call for a less severe penalty,”
, at 320 (internal quotation marks omitted); see
, at 320–321.
, we held that a
State cannot refuse to entertain other evidence of intellectual
disability when a defendant has an IQ score above 70. 572
U. S., at ___–___ (slip op., at 21–22). Although
left to the States “the task of
developing appropriate ways to enforce” the restriction on
executing the intellectually disabled, 572 U. S., at ___ (slip
op., at 17) (quoting Atkins
, 536 U. S., at 317),
States’ discretion, we cautioned, is not
“unfettered,” 572 U. S., at ___ (slip op., at
Even if “the views of medical experts” do
not “dictate” a court’s intellectual-disability
, at ___ (slip op., at 19), we clarified,
the determination must be “informed by the medical
community’s diagnostic framework,” id.
___–___ (slip op., at 19–20). We relied on the most
recent (and still current) versions of the leading diagnostic
manuals—the DSM–5 and AAIDD–11. Id.
___, ___, ___–___, ___–___ (slip op., at 3, 8,
10–11, 20–21). Florida, we concluded, had violated the
Eighth Amendment by “disregard[ing] established medical
, at ___ (slip op., at 10). We further
noted that Florida had parted ways with practices and trends in
other States. Id.
, at ___–___ (slip op., at
indicated that being informed by the
medical community does not demand adherence to everything stated in
the latest medical guide. But neither does our precedent license
disregard of current medical standards.
The CCA’s conclusion that Moore’s
IQ scores established that he is not intellectually disabled is
irreconcilable with Hall
instructs that, where
an IQ score is close to, but above, 70, courts must account for the
test’s “standard error of measurement.” See
, at ___–___, ___–___ (slip op., at
10–11, 21–22). See also Brumfield
, 576 U. S. ___, ___ (2015) (slip op., at 10)
(relying on Hall
to find unreasonable a state court’s
conclusion that a score of 75 precluded an intellectual-disability
finding). As we explained in Hall
, the standard error of
measurement is “a statistical fact, a reflection of the
inherent imprecision of the test itself.” 572 U. S., at
___ (slip op., at 10). “For purposes of most IQ tests,”
this imprecision in the testing instrument “means that an
individual’s score is best understood as a range of scores on
either side of the recorded score . . . within which one
may say an individual’s true IQ score lies.”
, at ___ (slip op., at 11). A test’s standard error
of measurement “reflects the reality that an
individual’s intellectual functioning cannot be reduced to a
single numerical score.” Ibid.
See also id.
___–___ (slip op., at 10–12); DSM–5, at 37;
AAIDD, User’s Guide: Intellectual Disability: Definition,
Classification, and Systems of Supports 22–23 (11th ed. 2012)
(hereinafter AAIDD–11 User’s Guide).
Moore’s score of 74, adjusted for the
standard error of measurement, yields a range of 69 to 79, see 470
S. W. 3d, at 519, as the State’s retained expert
acknowledged, see Brief for Petitioner 39, n. 18; App. 185,
189–190. Because the lower end of Moore’s score range
falls at or below 70, the CCA had to move on to consider
Moore’s adaptive functioning. See Hall
U. S., at ___–___ (slip op., at 21–22); 470
S. W. 3d, at 536 (Alcala, J., dissenting) (even if the
majority correctly limited the scores it would consider,
“current medical standards . . . would still
require [the CCA] to examine whether [Moore] has adaptive
Both Texas and the dissent maintain that the CCA
properly considered factors unique to Moore in disregarding the
lower end of the standard-error range. Post
, at 14–15;
Brief for Respondent 41–42; see supra
, at 6–7;
470 S. W. 3d, at 519. But the presence of other sources
of imprecision in administering the test to a particular
individual, see post
, at 14–16, and n. 3, cannot
the test-specific standard-error range.[7
In requiring the CCA to move on to consider
Moore’s adaptive functioning in light of his IQ evidence, we
do not suggest that “the Eighth Amendment turns on the
slightest numerical difference in IQ score,” post
invalidated Florida’s strict IQ
cutoff because the cutoff took “an IQ score as final and
conclusive evidence of a defendant’s intellectual capacity,
when experts in the field would consider other evidence.” 572
U. S., at ___ (slip op., at 10). Here, by contrast, we do not
end the intellectual-disability inquiry, one way or the other,
based on Moore’s IQ score. Rather, in line with Hall
we require that courts continue the inquiry and consider other
evidence of intellectual disability where an individual’s IQ
score, adjusted for the test’s standard error, falls within
the clinically established range for intellectual-functioning
The CCA’s consideration of Moore’s
adaptive functioning also deviated from prevailing clinical
standards and from the older clinical standards the court claimed
In concluding that Moore did not suffer
significant adaptive deficits, the CCA overemphasized Moore’s
perceived adaptive strengths. The CCA recited the strengths it
perceived, among them, Moore lived on the streets, mowed lawns, and
played pool for money. See 470 S. W. 3d, at 522–523,
526–527. Moore’s adaptive strengths, in the CCA’s
view, constituted evidence adequate to overcome the considerable
objective evidence of Moore’s adaptive deficits, see
, at 4; App. to Pet. for Cert. 180a–202a. See 470
S. W. 3d, at 522–524, 526–527. But the medical
community focuses the adaptive-functioning inquiry on adaptive
, AAIDD–11, at 47
(“significant limitations in conceptual, social, or practical
adaptive skills [are] not outweighed by the potential strengths in
some adaptive skills”); DSM–5, at 33, 38 (inquiry
should focus on “[d]eficits in adaptive functioning”;
deficits in only one of the three adaptive-skills domains suffice
to show adaptive deficits); see Brumfield
, 576 U. S.,
at ___ (slip op., at 15) (“[I]ntellectually 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.’ ” (quoting AAMR, Mental Retardation:
Definition, Classification, and Systems of Supports 8 (10th ed.
In addition, the CCA stressed Moore’s
improved behavior in prison. 470 S. W. 3d, at
522–524, 526–527. Clinicians, however, caution against
reliance on adaptive strengths developed “in a controlled
setting,” as a prison surely is. DSM–5, at 38
(“Adaptive functioning may be difficult to assess in a
controlled setting (e.g., prisons, detention centers); if possible,
corroborative information reflecting functioning outside those
settings should be obtained.”); see AAIDD–11
User’s Guide 20 (counseling against reliance on
“behavior in jail or prison”).
The CCA furthermore concluded that
Moore’s record of academic failure, along with the childhood
abuse and suffering he endured, detracted from a determination that
his intellectual and adaptive deficits were related. See 470
S. W. 3d, at 488, 526; supra
, at 5, 7–8.
Those traumatic experiences, however, count in the medical
community as “risk factors” for
disability. AAIDD–11, at 59–60 (emphasis added).
Clinicians rely on such factors as cause to explore the prospect of
intellectual disability further, not to counter the case for a
disability determination. See id.
, at 60 (“[A]t least
one or more of the risk factors [described in the manual] will be
found in every case of” intellectual disability.).
The CCA also departed from clinical practice by
requiring Moore to show that his adaptive deficits were not related
to “a personality disorder.” 470 S. W. 3d, at
488; see id.
, at 526 (Moore’s problems in kindergarten
were “more likely cause[d]” by “emotional
problems” than by intellectual disability). As mental-health
professionals recognize, how-ever, many intellectually disabled
people also have other mental or physical impairments, for example,
attention-deficit/hyperactivity disorder, depressive and bipolar
dis-orders, and autism. DSM–5, at 40 (“[c]o-occurring
men-tal, neurodevelopmental, medical, and physical conditions are
frequent in intellectual disability, with rates of some conditions
(e.g., mental disorders, cerebral palsy, and epilepsy) three to
four times higher than in the general population”); see
AAIDD–11, at 58–63. Coexisting conditions frequently
encountered in intellectually disabled individ-uals have been
described in clinical literature as
“[c]omorbidit[ies].” DSM–5, at 40. See also Brief
for AAIDD et al. as Amici Curiae
20, and n. 25.
The existence of a personality disorder or mental-health issue, in
short, is “not evidence that a person does not also have
intellectual disability.” Brief for American Psychological
Association, APA, et al. as Amici Curiae
The CCA’s attachment to the seven
evidentiary factors further impeded its assessment
of Moore’s adaptive functioning.
By design and in operation, the Briseno
factors “creat[e] an unacceptable risk that persons with
intellectual dis-ability will be executed,” Hall
U. S., at ___ (slip op., at 1). After observing that persons
with “mild” intellectual disability might be treated
differently under clinical standards than under Texas’
capital system, the CCA defined its objective as identifying the
“consensus of Texas citizens
” on who
“should be exempted from the death penalty.”
, 135 S. W. 3d, at 6 (emphasis added). Mild
levels of intellectual disability, although they may fall outside
Texas citizens’ consensus, nevertheless remain intellectual
disabilities, see Hall
, 572 U. S., at ___–___
(slip op., at 17–18); Atkins
, 536 U. S., at 308,
and n. 3; AAIDD–11, at 153, and States may not execute
anyone in “the entire category
disabled] offenders,” Roper
, 543 U. S., at
563–564 (emphasis added); see supra
, at 9.
Skeptical of what it viewed as
“exceedingly subjective” medical and clinical
standards, the CCA in Briseno
advanced lay perceptions of
intellectual disability. 135 S. W. 3d, at 8; see
, at 5–6, and n. 6. Briseno
example, “Did those who knew the person best during the
developmental stage—his family, friends, teachers, employers,
authorities—think he was mentally retarded at that time, and,
if so, act in accordance with that determination?” 135 S. W.
3d, at 8. Addressing that question here, the CCA referred to
Moore’s education in “normal classrooms during his
school career,” his father’s reactions to his academic
challenges, and his sister’s perceptions of Moore’s
intellectual abilities. 470 S. W. 3d, at 526–527.
But the medical profession has endeavored to counter lay
stereotypes of the intellectually disabled. See AAIDD–11
User’s Guide 25–27; Brief for AAIDD et al. as
9–14, and nn. 11–15. Those
stereotypes, much more than medical and clinical appraisals, should
factors are an outlier, in
comparison both to other States’ handling of
intellectual-disability pleas and to Texas’ own practices in
other contexts. See Hall
, 572 U. S., at ___ (slip op.,
at 12) (consensus in the States provides “objective indicia
of society’s standards in the context of the Eighth
Amendment” (internal quotation marks omitted)). No state
legislature has approved the use of the Briseno
anything similar. In the 12 years since Texas adopted the factors,
only one other state high court and one state intermediate
appellate court have authorized their use. See, e.g.
, 632 Pa. 75, ___–___,
117 A. 3d 270, 286–287 (2015); Howell
, 2011 WL 2420378, *18 (Tenn. Crim. App., June 14,
Indeed, Texas itself does not follow
in contexts other than the death penalty. See Brief
for Constitution Project as Amicus Curiae
example, the related-ness requirement Texas defends here, see
, at 5–6, is conspicuously absent from the
standards the State uses to assess students for intellectual
disabilities. See 19 Tex. Admin. Code §89.1040(c)(5) (2015).
And even within Texas’ criminal-justice system, the State
requires the intellectual-disability diagnoses of juveniles to be
based on “the latest edition of the DSM.” 37 Tex.
Admin. Code §380.8751(e)(3) (2016). Texas cannot
satisfactorily explain why it applies current medical standards for
diagnosing intellectual disability in other contexts, yet clings to
superseded standards when an individual’s life is at
As noted supra
, at 9, States have some
flexibility, but not “unfettered discretion,” in
’ holding. Hall
U. S., at ___ (slip op., at 17). “If the States were to
have complete autonomy to define intellectual disability as they
wished,” we have observed, “Atkins
a nullity, and the Eighth Amendment’s protection of human
dignity would not become a reality.” Id.
___–___ (slip op., at 18–19).
The medical community’s current standards
supply one constraint on States’ leeway in this area.
Reflecting improved understanding over time, see DSM–5, at 7;
AAIDD–11, at xiv–xv, current manuals offer “the
best available description of how mental disorders are expressed
and can be recognized by trained clinicians,” DSM–5, at
xli. See also Hall
, 572 U. S., at ___, ___, ___,
___–___, ___–___ (slip op., at 2, 3, 8, 10–11,
20–21) (employing current clinical standards); Atkins
536 U. S., at 308, n. 3, 317, n. 22 (relying on
In Moore’s case, the habeas court applied
current medical standards in concluding that Moore is
intellectually disabled and therefore ineligible for the death
penalty. See, e.g.
, App. to Pet. for Cert. 150a–151a,
200a–203a. The CCA, however, faulted the habeas court for
“disregarding [the CCA’s] case law and employing the
definition of intellectual disability presently used by the
AAIDD.” 470 S. W. 3d, at 486. The CCA instead
fastened its intellectual-disability determination to “the
AAMR’s 1992 definition of intellectual disability that [it]
adopted in Briseno
claims presented in
Texas death-penalty cases.” Ibid.
By rejecting the
habeas court’s application of medical guidance and clinging
to the standard it laid out in Briseno
, including the wholly
factors, the CCA failed adequately to
inform itself of the “medical community’s diagnostic
, 572 U. S., at ___–___
(slip op., at 19–20). Because Briseno
infected the CCA’s analysis, the decision of that court
* * *
For the reasons stated, the judgment of the
Texas Court of Criminal Appeals is vacated, and the case is
remanded for further proceedings not inconsistent with this
It is so ordered.