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SUPREME COURT OF THE UNITED STATES
_________________
No. 12–10882
_________________
FREDDIE LEE HALL, PETITIONER v. FLORIDA
on writ of certiorari to the supreme court of
florida
[May 27, 2014]
Justice Kennedy
delivered the opinion of the Court.
This Court has held
that the Eighth and Fourteenth Amendments to the Constitution
forbid the execution of persons with intellectual disability.
Atkins v. Virginia, 536 U. S. 304, 321 (2002) . Florida law
defines intellectual disability to require an IQ test score of 70
or less. If, from test scores, a prisoner is deemed to have an IQ
above 70, all further exploration of intellectual disability is
foreclosed. This rigid rule, the Court now holds, creates an
unacceptable risk that persons with intellectual disability will be
executed, and thus is unconstitutional.
I
On February 21, 1978,
Freddie Lee Hall, petitioner here, and his accomplice, Mark Ruffin,
kidnaped, beat, raped, and murdered Karol Hurst, a pregnant,
21-year-old newlywed. Afterward, Hall and Ruffin drove to a
convenience store they planned to rob. In the parking lot of the
store, they killed Lonnie Coburn, a sheriff’s deputy who
attempted to apprehend them. Hall received the death penalty for
both murders, although his sentence for the Coburn murder was later
reduced on account of insufficient evidence of premeditation. Hall
v. Florida, 403 So. 2d 1319, 1321 (Fla. 1981) (per
curiam).
Hall argues that he
cannot be executed because of his intellectual disability. Previous
opinions of this Court have employed the term “mental
retardation.” This opinion uses the term “intellectual
disability” to describe the identical phenomenon. See
Rosa’s Law, 124Stat. 2643 (changing entries in the U. S. Code
from “mental retardation” to “intellectual
disability”); Schalock et. al, The Renaming of Mental
Retardation: Understanding the Change to the Term Intellectual
Disability, 45 Intellectual & Developmental Disabilities 116
(2007). This change in terminology is approved and used in the
latest edition of the Diagnostic and Statistical Manual of Mental
Disorders, one of the basic texts used by psychiatrists and other
experts; the manual is often referred to by its initials
“DSM,” followed by its edition number, e.g.,
“DSM–5.” See American Psychiatric Association,
Diagnostic and Statistical Manual of Mental Disorders 33 (5th ed.
2013).
When Hall was first
sentenced, this Court had not yet ruled that the Eighth Amendment
prohibits States from imposing the death penalty on persons with
intellectual disability. See Penry v. Lynaugh, 492 U. S. 302,
340 (1989) . And at the time, Florida law did not consider
intellectual disability as a statutory mitigating factor.
After this Court held
that capital defendants must be permitted to present nonstatutory
mitigating evidence in death penalty proceedings, Hitchcock v.
Dugger, 481 U. S. 393 –399 (1987), Hall was resentenced.
Hall then presented substantial and unchallenged evidence of
intellectual disability. School records indicated that his teachers
identified him on numerous occasions as “[m]entally
retarded.” App. 482–483. Hall had been prosecuted for a
different, earlier crime. His lawyer in that matter later testified
that the lawyer “[c]ouldn’t really understand anything
[Hall] said.” Id., at 480. And, with respect to the murder
trial given him in this case, Hall’s counsel recalled that
Hall could not assist in his own defense because he had
“ ‘a mental . . . level much lower than his
age,’ ” at best comparable to the lawyer’s
4-year-old daughter. Brief for Petitioner 11. A number of medical
clinicians testified that, in their professional opinion, Hall was
“significantly retarded,” App. 507; was “mentally
retarded,” id., at 517; and had levels of understanding
“typically [seen] with toddlers,” id., at 523.
As explained below in
more detail, an individual’s ability or lack of ability to
adapt or adjust to the requirements of daily life, and success or
lack of success in doing so, is central to the framework followed
by psychiatrists and other professionals in diagnosing intellectual
disability. See DSM–5, at 37. Hall’s siblings testified
that there was something “very wrong” with him as a
child. App. 466. Hall was “slow with speech and . . . slow to
learn.” Id., at 490. He “walked and talked long after
his other brothers and sisters,” id., at 461, and had
“great difficulty forming his words,” id., at 467.
Hall’s upbringing
appeared to make his deficits in adaptive functioning all the more
severe. Hall was raised—in the words of the sentencing
judge—“under the most horrible family circumstances
imaginable.” Id., at 53. Al-though “[t]eachers and
siblings alike immediately recognized [Hall] to be
significantly mentally retarded . . . [t]his retardation did not
garner any sympathy from his mother, but rather caused much scorn
to befall him.” Id., at 20. Hall was “[c]onstantly
beaten because he was ‘slow’ or because he made simple
mistakes.” Ibid. His mother “would strap [Hall] to his
bed at night, with a rope thrown over a rafter. In the morning, she
would awaken Hall by hoisting him up and whipping him with a belt,
rope, or cord.” Ibid. Hall was beaten “ten or fifteen
times a week sometimes.” Id., at 477. His mother tied him
“in a ‘croaker’ sack, swung it over a fire, and
beat him,” “buried himin the sand up to his neck to
‘strengthen his legs,’ ” and “held a
gun on Hall . . . while she poked [him] with sticks.” Hall v.
Florida, 614 So. 2d 473, 480 (Fla. 1993) (Barkett, C. J.,
dissenting).
The jury,
notwithstanding this testimony, voted to sentence Hall to death,
and the sentencing court adopted the jury’s recommendation.
The court found that there was “substantial evidence in the
record” to support the finding that “Freddie Lee Hall
has been mentally retarded his entire life.” App. 46. Yet the
court also “suspect[ed] that the defense experts [were]
guilty of some professional overkill,” because
“[n]othing of which the experts testified could explain how a
psychotic, mentally-retarded, brain-damaged, learning-disabled,
speech-impaired person could formulate a plan whereby a car was
stolen and a convenience store was robbed.” Id., at 42. The
sentencing court went on to state that, even assuming the expert
testimony to be accurate, “the learning disabilities, mental
retardation, and other mental
difficulties . . . cannot be used to justify,
excuse or extenuate the moral culpability of the defendant in this
cause.” Id., at 56. Hall was again sentenced to death. The
Florida Supreme Court affirmed, concluding that “Hall’s
argument that his mental retardation provided a pretense of moral
or legal justification” had “no merit.” Hall, 614
So. 2d, at 478. Chief Justice Barkett dissented, arguing that
executing a person with intellectual disability violated the State
Constitution’s prohibition on cruel and unusual punishment.
Id., at 481–482.
In 2002, this Court
ruled that the Eighth Amendment prohibited the execution of persons
with intellectual disability. Atkins v. Virginia, 536 U. S.,
at 321. On November 30, 2004, Hall filed a motion claiming that he
had intellectual disability and could not be executed. More than
five years later, Florida held a hearing to consider Hall’s
motion. Hall again presented evidence of intellectual disability,
including an IQ test score of 71. (Hall had received nine IQ
evaluations in 40 years, with scores ranging from 60 to 80, Brief
for Respondent 8, but the sentencing court excluded the two scores
below 70 for evidentiary reasons, leaving only scores between 71
and 80. See App. 107; 109 So. 3d 704, 707 (Fla. 2012)). In
response, Florida argued that Hall could not be found
intellectually disabled because Florida law requires that, as a
threshold matter, Hall show an IQ test score of 70 or below before
presenting any additional evidence of his intellectual disability.
App. 278–279 (“[U]nder the law, if an I. Q. is above
70, a person is not mentally retarded”). The Florida Supreme
Court rejected Hall’s appeal and held that Florida’s
70-point threshold was constitutional. 109 So. 3d, at
707–708.
This Court granted
certiorari. 571 U. S. ___ (2013).
II
The Eighth Amendment
provides that “[e]xcessive bail shall not be required, nor
excessive fines imposed, nor cruel and unusual punishments
inflicted.” The Fourteenth Amendment applies those
restrictions to the States. Roper v. Simmons, 543 U. S. 551,
560 (2005) ; Furman v. Georgia, 408 U. S. 238 –240
(1972) (per curiam). “By protecting even those convicted of
heinous crimes, the Eighth Amendment reaffirms the duty of the
government to respect the dignity of all persons.” Roper,
supra, at 560; see also Trop v. Dulles, 356 U. S. 86, 100
(1958) (plurality opinion) (“The basic concept underlying the
Eighth Amendment is nothing less than the dignity of
man”).
The Eighth Amendment
“is not fastened to the obsolete but may acquire meaning as
public opinion becomes enlightened by a humane justice.”
Weems v. United States, 217 U. S. 349, 378 (1910) . To enforce
the Constitution’s protection of human dignity, this Court
looks to the “evolving standards of decency that mark the
progress of a maturing society.” Trop, supra, at 101. The
Eighth Amendment’s protection of dignity reflects the Nation
we have been, the Nation we are, and the Nation we aspire to be.
This is to affirm that the Nation’s constant, unyielding
purpose must be to transmit the Constitution so that its precepts
and guarantees retain their meaning and force.
The Eighth Amendment
prohibits certain punishments as a categorical matter. No
natural-born citizen may be denaturalized. Ibid. No person may be
sentenced to death for a crime committed as a juvenile. Roper,
supra, at 578. And, as relevant for this case, persons with
intellectual disability may not be executed. Atkins, 536
U. S., at 321.
No legitimate
penological purpose is served by executing a person with
intellectual disability. Id., at 317, 320. To do so contravenes the
Eighth Amendment, for to impose the harshest of punishments on an
intellectually disabled person violates his or her inherent dignity
as a human being. “[P]unishment is justified under one or
more of three principal rationales: rehabilitation, deterrence, and
retribution.” Kennedy v. Louisiana, 554 U. S. 407, 420
(2008) . Rehabilitation, it is evident, is not an applicable
rationale for the death penalty. See Gregg v. Georgia, 428
U. S. 153, 183 (1976) (joint opinion of Stewart, Powell, and
Stevens, JJ.). As for deterrence, those with intellectual
disability are, by reason of their condition, likely unable to make
the calculated judgments that are the premise for the deterrence
rationale. They have a “diminished ability” to
“process information, to learn from experience, to engage in
logical reasoning, or to control impulses . . . [which] make[s] it
less likely that they can process the information of the
possibility of execution as a penalty and, as a result, control
their conduct based upon that information.” Atkins, 536
U. S., at 320. Retributive values are also ill-served by
executing those with intellectual disability. The diminished
capacity of the intellectually disabled lessens moral culpability
and hence the retributive value of the punishment. See id., at 319
(“If the culpability of the average murderer is insufficient
to justify the most extreme sanction available to the State, the
lesser culpability of the mentally retarded offender surely does
not merit that form of retribution”).
A further reason for
not imposing the death penalty on a person who is intellectually
disabled is to protect the integrity of the trial process. These
persons face “a special risk of wrongful execution”
because they are more likely to give false confessions, are often
poor witnesses, and are less able to give meaningful assistance to
their counsel. Id., at 320–321. This is not to say that under
current law persons with intellectual disability who “meet
the law’s requirements for criminal responsibility” may
not be tried and punished. Id., at 306. They may not, however,
receive the law’s most severe sentence. Id., at 318.
The question this case
presents is how intellectual disability must be defined in order to
implement these principles and the holding of Atkins. To determine
if Florida’s cutoff rule is valid, it is proper to consider
the psychiatric and professional studies that elaborate on the
purpose and meaning of IQ scores to determine how the scores relate
to the holding of Atkins. This in turn leads to a better
understanding of how the legislative policies of various States,
and the holdings of state courts, implement the Atkins rule. That
understanding informs our determination whether there is a
consensus that instructs how to decide the specific issue presented
here. And, in conclusion, this Court must express its own
independent determination reached in light of the instruction found
in those sources and authorities.
III
A
That this Court,
state courts, and state legislatures consult and are informed by
the work of medical experts in determining intellectual disability
is unsurprising. Those professionals use their learning and skills
to study and consider the consequences of the classification
schemes they devise in the diagnosis of persons with mental or
psychiatric disorders or disabilities. Society relies upon medical
and professional expertise to define and explain how to diagnose
the mental condition at issue. And the definition of intellectual
disability by skilled professionals has implications far beyond the
confines of the death penalty: for it is relevant to education,
access to social programs, and medical treatment plans. In
determining who qualifies as intellectually disabled, it is proper
to consult the medical community’s opinions.
As the Court noted in
Atkins, the medical community defines intellectual disability
according to three criteria: significantly subaverage intellectual
functioning, deficits in adaptive functioning (the inability to
learn basic skills and adjust behavior to changing circumstances),
and onset of these deficits during the developmental period. See
id., at 308, n. 3; DSM–5, at 33; Brief for American
Psychological Association et al. as Amici Curiae 12–13
(hereinafter APA Brief). This last factor, referred to as
“age of onset,” is not at issue.
The first and second
criteria—deficits in intellectual functioning and deficits in
adaptive functioning—are central here. In the context of a
formal assessment, “[t]he existence of concurrent deficits in
intellectual and adaptive functioning has long been the defining
characteristic of intellectual disability.” Id., at 11.
On its face, the
Florida statute could be consistent with the views of the medical
community noted and discussed in Atkins. Florida’s statute
defines intellectual disability for purposes of an Atkins
proceeding as “significantly subaverage general intellectual
functioning existing concurrently with deficits in adaptive
behavior and manifested during the period from conception to age
18.” Fla. Stat. §921.137(1) (2013). The statute further
defines “significantly subaverage general intellectual
functioning” as “performance that is two or more
standard deviations from the mean score on a standardized
intelligence test.” Ibid. The mean IQ test score is 100. The
concept of standard deviation describes how scores are dispersed in
a population. Standard deviation is distinct from standard error of
measurement, a concept which describes the reliability of a test
and is discussed further below. The standard deviation on an IQ
test is approximately 15 points, and so two standard deviations is
approximately 30 points. Thus a test taker who performs “two
or more standard deviations from the mean” will score
approximately 30 points below the mean on an IQ test, i.e., a score
of approximately 70 points.
On its face this
statute could be interpreted consistently with Atkins and with the
conclusions this Court reaches in the instant case. Nothing in the
statute precludes Florida from taking into account the IQ
test’s standard error of measurement, and as discussed below
there is evidence that Florida’s Legislature intended to
include the measurement error in the calculation. But the Florida
Supreme Court has interpreted the provisions more nar-rowly. It has
held that a person whose test score is above 70, including a score
within the margin for measurement error, does not have an
intellectual disability and is barred from presenting other
evidence that would show his faculties are limited. See Cherry v.
State, 959 So. 2d 702, 712–713 (Fla. 2007) (per curiam).
That strict IQ test score cutoff of 70 is the issue in this
case.
Pursuant to this
mandatory cutoff, sentencing courts cannot consider even
substantial and weighty evidence of intellectual disability as
measured and made manifest by the defendant’s failure or
inability to adapt to his social and cultural environment,
including medical histories, behavioral records, school tests and
reports, and testimony regarding past behavior and family
circumstances. This is so even though the medical community accepts
that all of this evidence can be probative of intellectual
disability, including for individuals who have an IQ test score
above 70. See APA Brief 15–16 (“[T]he relevant clinical
authorities all agree that an individual with an IQ score above 70
may properly be diagnosed with intellectual disability if
significant limitations in adaptive functioning also exist”);
DSM–5, at 37 (“[A] person with an IQ score above 70 may
have such severe adaptive behavior problems . . . that the
person’s actual functioning is comparable to that of
individuals with a lower IQ score”).
Florida’s rule
disregards established medical practice in two interrelated ways.
It takes an IQ score as final and conclusive evidence of a
defendant’s intellectual capacity, when experts in the field
would consider other evidence. It also relies on a purportedly
scientific measurement of the defendant’s abilities, his IQ
score, while refusing to recognize that the score is, on its own
terms, imprecise.
The professionals who
design, administer, and interpret IQ tests have agreed, for years
now, that IQ test scores should be read not as a single fixed
number but as a range. See D. Wechsler, The Measurement of Adult
Intelligence 133 (3d ed. 1944) (reporting the range of error on an
early IQ test). Each IQ test has a “standard error of
measurement,” ibid., often referred to by the abbreviation
“SEM.” A test’s SEM is a statistical fact, a
reflection of the inherent imprecision of the test itself. See R.
Furr & V. Bacharach, Psychometrics 118 (2d ed. 2014)
(identifying the SEM as “one of the most important concepts
in measurement theory”). An individual’s IQ test score
on any given exam may fluctuate for a variety of reasons. These
include the test-taker’s health; practice from earlier tests;
the environment or location of the test; the examiner’s
demeanor; the subjective judgment involved in scoring certain
questions on the exam; and simple lucky guessing. See American
Association on Intellectual and Developmental Disabilities, R.
Schalock et al., User’s Guide To Accompany the 11th
Edition of Intellectual Disability: Definition, Classification, and
Systems of Supports 22 (2012) (hereinafter AAIDD Manual); A.
Kaufman, IQ Testing 101, pp. 138–139 (2009).
The SEM reflects the
reality that an individual’s intellectual functioning cannot
be reduced to a single numerical score. For purposes of most IQ
tests, the SEM means that an individual’s score is best
understood as a range of scores on either side of the recorded
score. The SEM allows clinicians to calculate a range within which
one may say an individual’s true IQ score lies. See APA Brief
23 (“SEM is a unit of measurement: 1 SEM equates to a
confidence of 68% that the measured score falls within a given
score range, while 2 SEM provides a 95% confidence level that the
measured score is within a broader range”). A score of 71,
for instance, is generally considered to reflect a range between 66
and 76 with 95% confidence and a range of 68.5 and 73.5 with a 68%
confidence. See DSM–5, at 37 (“Individuals with
intellectual disability have scores of approximately two standard
deviations or more below the population mean, including a margin
for measurement error (generally +5 points). . . . [T]his involves
a score of 65–75 (70 ± 5)”); APA Brief 23
(“For example, the average SEM for the WAIS-IV is 2.16 IQ
test points and the average SEM for the Stanford-Binet 5 is 2.30 IQ
test points (test manuals report SEMs by different age groupings;
these scores are similar, but not identical, often due to sampling
error)”). Even when a person has taken multiple tests, each
separate score must be assessed using the SEM, and the analysis of
multiple IQ scores jointly is a complicated endeavor. See
Schneider, Principles of Assessment of Aptitude and Achievement, in
The Oxford Handbook of Child Psychological Assessment 286,
289–291, 318 (D. Saklofske, C. Reynolds, V. Schwean, eds.
2013). In addition, because the test itself may be flawed, or
administered in a consistently flawed manner, multiple examinations
may result in repeated similar scores, so that even a consistent
score is not conclusive evidence of intellectual functioning.
Despite these
professional explanations, Florida law used the test score as a
fixed number, thus barring further consideration of other evidence
bearing on the question of intellectual disability. 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 indicating whether the person had
deficits in adaptive functioning. These include evidence of past
performance, environment, and upbringing.
B
A significant
majority of States implement the protections of Atkins by taking
the SEM into account, thus acknowledging the error inherent in
using a test score without necessary adjustment. This calculation
provides “objective indicia of society’s
standards” in the context of the Eighth Amendment. Roper, 543
U. S., at 563. Only the Kentucky and Virginia Legislatures
have adopted a fixed score cutoff identical to Florida’s. Ky.
Rev. Stat. Ann. §532.130(2) (Lexis Supp. 2013); Bowling v.
Commonwealth, 163 S. W. 3d 361, 375 (Ky. 2005); Va. Code Ann.
§19.2–264.3:1.1 (Lexis Supp. 2013); Johnson v.
Commonwealth, 267 Va. 53, 75, 591 S. E. 2d 47, 59 (2004),
vacated and remanded on other grounds, 544 U. S. 901 (2005) .
Alabama also may use a strict IQ score cutoff at 70, although not
as a result of legislative action. See Smith v. State, 71 So. 3d
12, 20 (Ala. Crim. App. 2008) (“The Alabama Supreme Court . .
. did not adopt any ‘margin of error’ when examining a
defendant’s IQ score”). Petitioner does not question
the rule in States which use a bright-line cutoff at 75 or greater,
Tr. of Oral Arg. 9, and so they are not included alongside Florida
in this analysis.
In addition to these
States, Arizona, Delaware, Kansas, North Carolina, and Washington
have statutes which could be interpreted to provide a bright-line
cutoff leading to the same result that Florida mandates in its
cases. See Ariz. Rev. Stat. Ann. §13–753(F) (West 2013);
Del. Code Ann. Tit. 11, §4209(d)(3) (2012 Supp.); Kan. Stat.
Ann. §76–12b01 (2013 Supp.); N. C. Gen. Stat. Ann.
§15A–2005 (Lexis 2013); Wash. Rev. Code
§10.95.030(2)(c) (2012). That these state laws might be
interpreted to require a bright-line cutoff does not mean that they
will be so interpreted, however. See, e.g., State v. Vela, 279 Neb.
94, 126, 137, 777 N. W. 2d 266, 292, 299 (2010) (Although
Nebraska’s statute specifies “[a]n intelligence
quotient of seventy or below on a reliably administered
intelligence quotient test,” “[t]he district court
found that [the defendant’s] score of 75 on the [IQ test],
considered in light of the standard error of measurement, could be
considered as subaverage general intellectual functioning for
purposes of diagnosing mental retardation”).
Arizona’s statute
appears to set a broad statutory cutoff at 70, Ariz. Rev. Stat.
Ann. §13–753(F) (West 2013), but another provision
instructs courts to “take into account the margin of error
for a test administered.” Id. at §14-753(K)(5). How
courts are meant to interpret the statute in a situation like
Hall’s is not altogether clear. The principal Arizona case on
the matter, State v. Roque, 141 P. 3d 368, (Ariz 2006), states
that “the statute accounts for margin of error by requiring
multiple tests,” and that “if the defendant achieves a
full-scale score of 70 or below on any one of the tests, then the
court proceeds to a hearing.” Id. at 403. But that case also
notes that the defendant had an IQ score of 80, well outside the
margin of error, and that all but one of the sub-parts of the IQ
test were “above 75.” Id.
Kansas has not had an
execution in almost five decades, and so its laws and jurisprudence
on this issue are unlikely to receive attention on this specific
question. See Atkins, 536 U. S., at 316 (“[E]ven in
those States that allow the execution of mentally retarded
offenders, the practiceis uncommon. Some States . . . continue to
authorize executions, but none have been carried out in decades.
Thus there is little need to pursue legislation barring the
execution of the mentally retarded in those States”).
Delaware has executed three individuals in the past decade, while
Washington has executed one person, and has recently suspended its
death penalty. None of the four individuals executed recently in
those States appears to have brought a claim similar to that
advanced here.
Thus, at most nine
States mandate a strict IQ score cutoff at 70. Of these, four
States (Delaware, Kansas, North Carolina, and Washington) appear
not to have considered the issue in their courts. On the other side
of the ledger stand the 18 States that have abolished the death
penalty, either in full or for new offenses, and Oregon, which has
suspended the death penalty and executed only two individuals in
the past 40 years. See Roper, 543 U. S., at 574 (“[The]
Court should have considered those States that had abandoned the
death penalty altogether as part of the consensus against the
juvenile death penalty”). In those States, of course, a
person in Hall’s positioncould not be executed even without a
finding of intellectual disability. Thus in 41 States an individual
in Hall’sposition—an individual with an IQ score of
71—would not be deemed automatically eligible for the death
penalty.
These aggregate numbers
are not the only considerations bearing on a determination of
consensus. Consistency of the direction of change is also relevant.
See id., at565–566 (quoting Atkins, supra, at 315). Since
Atkins, many States have passed legislation to comply with the
constitutional requirement that persons with intellectual
disability not be executed. Two of these States, Virginia and
Delaware, appear to set a strict cutoff at 70, although as
discussed, Delaware’s courts have yet to interpret the law.
In contrast, at least 11 States have either abolished the death
penalty or passed legislation allowing defendants to present
additional evidence of intellectual disability when their IQ test
score is above 70.
Since Atkins, five
States have abolished the death penalty through legislation. See
2012 Conn. Pub. Acts no. 12–5; Ill. Comp. Stat. ch. 725,
§119–1 (West 2012); Md. Correc. Servs. Code Ann.
§3–901 et seq. (Lexis 2008); N. J. Stat. Ann.
§2C:11–3(b)(1) (West Supp. 2013); 2009 N. M. Laws ch.
11, §§5–7. In addition, the New York Court of
Appeals invalidated New York’s death penalty under the State
Constitution in 2004, see People v. LeValle, 3 N. Y. 3d 88,
817 N. E. 2d 341 (2004), and legislation has not been passed
to reinstate it. And when it did impose the death penalty, New York
did not employ an IQ cutoff in determining intellectual disability.
N. Y. Crim. Proc. Law Ann. §400.27(12)(e) (West
2005).
In addition to these
States, at least five others have passed legislation allowing a
defendant to present additional evidence of intellectual disability
even when an IQ test score is above 70. See Cal. Penal Code Ann.
§1376 (West Supp. 2014) (no IQ cutoff); Idaho Code
§19–2515A (Lexis Supp. 2013) (“seventy (70) or
below”); Pizzutto v. State, 146 Idaho 720, 729, 202
P. 3d 642, 651 (2008) (“The alleged error in IQ testing
is plus or minus five points. The district court was entitled to
draw reasonable inferences from the undisputed facts”); La.
Code Crim. Proc. Ann., Art. 905.5.1 (West Supp. 2014) (no IQ
cutoff); Nev. Rev. Stat. §174.098.7 (2013) (no IQ cutoff);
Utah Code Ann §77–15a–102 (Lexis 2012) (no IQ
cutoff). The U. S. Code likewise does not set a strict IQ
cutoff. See 18 U. S. C. §3596(c). And no State that
previously allowed defendants with an IQ score over 70 to present
additional evidence of intellectual disability has modified its law
to create a strict cutoff at 70. Cf. Roper, supra, at 566
(“Since Stanford v. Kentucky, 492 U. S. 361 (1989) , no
State that previously prohibited capital punishment for juveniles
has reinstated it”).
In summary, every state
legislature to have considered the issue after Atkins—save
Virginia’s—and whose law has been interpreted by its
courts has taken a position contrary to that of Florida. Indeed,
the Florida Legislature, which passed the relevant legislation
prior to Atkins, might well have believed that its law would not
createa fixed cutoff at 70. The staff analysis accompanyingthe 2001
bill states that it “does not contain a set
IQlevel . . . . Two standard deviations
from these tests is ap-proximately a 70 IQ, although it can be
extended up to 75.” Fla. Senate Staff Analysis and Economic
Impact Statement, CS/SB 238, p. 11 (Feb. 14, 2001). But the Florida
Supreme Court interpreted the law to require a bright-line cutoff
at 70, see Cherry, 959 So. 2d, at 712–713, and the Court
is bound by that interpretation.
The rejection of the
strict 70 cutoff in the vast majority of States and the
“consistency in the trend,” Roper, supra, at 567,
toward recognizing the SEM provide strong evidence of consensus
that our society does not regard this strict cutoff as proper or
humane.
C
Atkins itself
acknowledges the inherent error in IQ testing. It is true that
Atkins “did not provide definitive procedural or substantive
guides for determining when a person who claims mental
retardation” falls within the protection of the Eighth
Amendment. Bobby v. Bies, 556 U. S. 825, 831 (2009) . In
Atkins, the Court stated:
“Not 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. As was our approach in Ford v. Wainwright with regard to
insanity, ‘we leave to the State[s] the task of developing
appropriate ways to enforce the constitutional restriction upon
[their] execution of sentences.’ ” 536 U. S.,
at 317 (quoting Ford v. Wainwright, 477 U. S. 399 –417
(1986); citation omitted).
As discussed above, the States play a critical
role in advancing protections and providing the Court with
information that contributes to an understanding of how
intellectual disability should be measured and assessed. But Atkins
did not give the States unfettered discretion to define the full
scope of the constitutional protection.
The Atkins Court twice
cited definitions of intellectual disability which, by their
express terms, rejected a strict IQ test score cutoff at 70. Atkins
first cited the definition provided in the DSM–IV:
“ ‘Mild’ mental retardation is typically
used to describe people with an IQ level of 50–55 to
approximately 70.” 536 U. S., at 308, n. 3 (citing
Diagnostic and Statistical Manual of Mental Disorders 41 (4th ed.
2000)). The Court later noted 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. Furthermore, immediately after the Court declared that
it left “ ‘to the States the task of developing
appropriate ways to enforce the constitutional
restriction,’ ” id., at 317, the Court stated in
an accompanying footnote that “[t]he [state] statutory
definitions of mental retardation are not identical, but generally
conform to the clinical definitions,” ibid.
Thus Atkins itself not
only cited clinical definitions for intellectual disability but
also noted that the States’ standards, on which the Court
based its own conclusion, conformed to those definitions. In the
words of Atkins, those persons who meet the “clinical
definitions” of intellectual disability “by
definition . . . have diminished
capacities to understand and process information, to
communicate, to abstract from mistakes and learn from experience,
to engage in logical reasoning, to control impulses, and to
understand the reactions of others.” Id., at 318. Thus, they
bear “diminish[ed] . . . personal culpability.” Ibid.
The clinical definitions of intellectual disability, which take
into account that IQ scores represent a range, not a fixed number,
were a fundamental premise of Atkins. And those clinical
definitions have long included the SEM. See Diagnostic and
Statistical Manual of Mental Disorders 28 (rev. 3d ed. 1987)
(“Since any measurement is fallible, an IQ score is generally
thought to involve an error of measurement of approximately five
points; hence, an IQ of 70 is considered to represent a band or
zone of 65 to 75. Treating the IQ with some flexibility permits
inclusion in the Mental Retardation category of people with IQs
somewhat higher than 70 who exhibit significant deficits in
adaptive behavior”).
Respondent argues that
the current Florida law was favorably cited by the Atkins Court.
See Brief for Respondent 18 (“As evidence of the national
consensus, the Court specifically cited Florida’s statute at
issue here, which has not substantively changed”). While
Atkins did refer to Florida’s law in a citation listing
States which had outlawed the execution of the intellectually
disabled, 536 U. S., at 315, that fleeting mention did not
signal the Court’s approval of Florida’s current
understanding of the law. As discussed above, when Atkins was
decided the Florida Supreme Court had not yet interpreted the law
to require a strict IQ cutoff at 70. That new interpretation runs
counter to the clinical definition cited throughout Atkins and to
Florida’s own legislative report indicating this kind of
cutoff need not be used.
Respondent’s
argument also conflicts with the logic of Atkins and the Eighth
Amendment. If the States were to have complete autonomy to define
intellectual disability as they wished, the Court’s decision
in Atkins could become a nullity, and the Eighth Amendment’s
protection of human dignity would not become a reality. This Court
thus reads Atkins to provide substantial guidance on the definition
of intellectual disability.
D
The actions of the
States and the precedents of this Court “give us essential
instruction,” Roper, 543 U. S., at 564, but the inquiry
must go further. “[T]he Constitution contemplates that in the
end our own judgment will be brought to bear on the question of the
acceptability of the death penalty under the Eighth
Amendment.” Coker v. Georgia, 433 U. S. 584, 597 (1977)
(plurality opinion). That exercise of independent judgment is the
Court’s judicial duty. See Roper, supra, at 574 (“[T]o
the extent Stanford was based on a rejection of the idea that this
Court is required to bring its independent judgment to bear on the
proportionality of the death penalty for a particular class of
crimes or offenders, it suffices to note that this rejection was
inconsistent with prior Eighth Amendment decisions” (citation
omitted).
In this Court’s
independent judgment, the Florida statute, as interpreted by its
courts, is unconstitutional.
In addition to the
views of the States and the Court’s precedent, this
determination is informed by the views of medical experts. These
views do not dictate the Court’s decision, yet the Court does
not disregard these informed assessments. See Kansas v. Crane, 534
U. S. 407, 413 (2002) (“[T]he science of psychiatry . .
. informs but does not control ultimate legal
determinations . . .”). It is the
Court’s duty to interpret the Constitution, but it need not
do so in isolation. The legal determination of intellectual
disability is distinct from a medical diagnosis, but it is informed
by the medical community’s diagnostic framework. Atkins
itself points to the diagnostic criteria employed by psychiatric
professionals. And the professional community’s teachings are
of particular help in this case, where no alternative definition of
intellectual disability is presented and where this Court and the
States have placed substantial reliance on the expertise of the
medical profession.
By failing to take into
account the SEM and setting a strict cutoff at 70, Florida
“goes against the unanimous professional consensus.”
APA Brief 15. Neither Florida nor its amici point to a single
medical professional who supports this cutoff. The DSM–5
repudiates it: “IQ test scores are approximations of
conceptual functioning but may be insufficient to assess reasoning
in real-life situations and mastery of practical tasks.”
DSM–5, at 37. This statement well captures the Court’s
independent assessment that an individual with an IQ test score
“between 70 and 75 or lower,” Atkins, supra, at 309,
n. 5, may show intellectual disability by presenting
additional evidence regarding difficulties in adaptive
functioning.
The flaws in
Florida’s law are the result of the inherent error in IQ
tests themselves. An IQ score is an approximation, not a final and
infallible assessment of intellectual functioning. See APA Brief 24
(“[I]t is standard pyschometric practice to report the
‘estimates of relevant reliabilities and standard errors of
measurement’ when reporting a test score”); ibid. (the
margin of error is “inherent to the accuracy of IQ
scores”); Furr, Psychometrics, at 119 (“[T]he standard
error of measurement is an important psychometric value with
implications for applied measurement”). SEM is not a concept
peculiar to the psychiatric profession and IQ tests. It is a
measure that is recognized and relied upon by those who create and
devise tests of all sorts. Id., at 118 (identifying the SEM as
“one of the most important concepts in measurement
theory”).
This awareness of the
IQ test’s limits is of particular importance when conducting
the conjunctive assessment necessary to assess an
individual’s intellectual ability. See American Association
on Intellectual and Developmental Disabilities, Intellectual
Disability: Definition, Classification, and Systems of Supports 40
(11th ed. 2010) (“It must be stressed that the diagnosis of
[intellectual disability] is intended to reflect a clinical
judgment rather than an actuarial determination”).
Intellectual disability
is a condition, not a number. See DSM–5, at 37. Courts must
recognize, as does the medical community, that the IQ test is
imprecise. This is not to say that an IQ test score is unhelpful.
It is of considerable significance, as the medical community
recognizes. But in using these scores to assess a defendant’s
eligibility for the death penalty, a State must afford these test
scores the same studied skepticism that those who design and use
the tests do, and understand that an IQ test score represents a
range rather than a fixed number. A State that ignores the inherent
imprecision of these tests risks executing a person who suffers
from intellectual disability. See APA Brief 17 (“Under the
universally accepted clinical standards for diagnosing intellectual
disability, the court’s determination that Mr. Hall is not
intellectually disabled cannot be considered valid”).
This Court agrees with
the medical experts that when a defendant’s IQ test score
falls within the test’s acknowledged and inherent margin of
error, the defendant must be able to present additional evidence of
intellectual disability, including testimony regarding adaptive
deficits.
It is not sound to view
a single factor as dispositive of a conjunctive and interrelated
assessment. See DSM–5, at 37 (“[A] person with an IQ
score above 70 may have such severe adaptive behavior
problems . . . that the person’s actual
functioning is comparable to that of individuals with a lower IQ
score”). The Florida statute, as interpreted by its courts,
misuses IQ score on its own terms; andthis, in turn, bars
consideration of evidence that must be considered in determining
whether a defendant in a capital case has intellectual disability.
Florida’s rule is invalid under the Constitution’s
Cruel and Unusual Punishments Clause.
E
Florida seeks to
execute a man because he scored a 71 instead of 70 on an IQ test.
Florida is one of just a few States to have this rigid rule.
Florida’s rule misconstrues the Court’s statements in
Atkins that intellectually dis-ability is characterized by an IQ of
“approximately 70.” 536U. S., at 308, n. 3.
Florida’s rule is in direct opposition to the views of those
who design, administer, and interpret the IQ test. By failing to
take into account the standard error of measurement,
Florida’s law not only contradicts the test’s own
design but also bars an essential part of a sentencing
court’s inquiry into adaptive functioning. Freddie Lee Hall
may or may not be intellectually dis-abled, but the law requires
that he have the opportunity topresent evidence of his intellectual
disability, including deficits in adaptive functioning over his
lifetime.
The death penalty is
the gravest sentence our society may impose. Persons facing that
most severe sanction must have a fair opportunity to show that the
Constitution prohibits their execution. Florida’s law
contravenes our Nation’s commitment to dignity and its duty
to teach human decency as the mark of a civilized world. The States
are laboratories for experimentation, but those experiments may not
deny the basic dignity the Constitution protects.
The judgment of the
Florida Supreme Court is reversed, and the case is remanded for
further proceedings not inconsistent with this opinion.
So ordered.