This Court has held that the Eighth and Fourteenth Amendments to the Constitution forbid the execution of persons with intellectual disability.

at 828–29). Indeed, Justice Breyer has already made his position known. In Atkins, we instructed that "clinical definitions of mental retardation require not only [(1)] subaverage intellectual functioning, but also [(2)] significant limitations in adaptive skills."

Compare Ybarra v. State, 127 Nev. ___, ___, 247 P. 3d 269, 274 (2011), with State v. Dunn, 2001-1635, pp. One State's Supreme Court mentioned measurement errors but only to explain why a defendant must prove deficits in adaptive behavior despite having an IQ below 70. Al-though "[t]eachers and siblings alike immediately recognized [Hall] to be significantly mentally retarded . Practical problems like these call for legislative judgments, not judicial resolution. 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. Hall v. Florida, 403 So. See ante, at 9-10, 12, 20. And in the absence of such a consensus, we have no basis for holding that Florida's method contravenes our society's standards of decency. 1992) (hereinafter AAMR 9th ed. and had previously presented an IQ score of 60,17×17. App. Indeed, Justices dissenting in process cases have sometimes faulted the majority’s failure to consider national consensus. Trop, supra, at 101. Hall argues that states should not use strict IQ scores cutoffs because IQ scores contain a degree of error and lack precision.

."

Because “[t]he appropriate confidence level is ultimately a judgment best left to legislatures” and because “Florida’s system already accounts for the risk of testing error by allowing the introduction of multiple test scores,”61×61. The Court then concludes that a State must view a defendant's IQ as a range of potential scores calculated using a statistical concept known as the "standard error of measurement" or SEM. ); N. C. Gen. Stat. 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. Id., at 118 (identifying the SEM as "one of the most important concepts in measurement theory"). For all these reasons, it is quite wrong for the Court to proclaim that "the vast majority of States" have rejected Florida's approach. Additionally, the Court concludes that all but one state that has considered this issue after Atkins has taken a position contrary to that of Florida. Unless convincingly limited, Hall could plausibly be read to extend national consensus inquiry into the realm of procedure. These include evidence of past performance, environment, and upbringing.

The States play a critical role in advancing the protections of Atkins and providing this Court with an understanding of how intellectual disability should be measured and assessed, but Atkins did not give them unfettered discretion to define the full scope of the constitutional protection. Since Atkins, many States have passed legislation to comply with the constitutional requirement that persons with intellectual disability not be executed. Indeed, last Term, Justice Sotomayor, joined by Justice Breyer, drew on national consensus when dissenting from a denial of certiorari on Alabama’s practice of allowing judges to overturn a capital sentencing jury’s recommendation of mercy.100×100. Ibid. 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. Audio Transcription for Oral Argument - March 03, 2014 in Hall v. Florida Audio Transcription for Opinion Announcement - May 27, 2014 in Hall v. Florida .

(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"). App. 725, §119-1 (West 2012); Md. . While some early process cases inquired into national consensus,76×76. Stat.

The Court specifies that Florida statute § 921.137, as interpreted, uses the IQ score as "final and conclusive evidence" of intellectual disability, but that experts in the field would consider other evidence concurrently with the IQ score.

Furthermore, the states argue that clinical definitions of mental retardation provide an inconsistent framework because they change rapidly. Id., at 318.

it also comes within the Court’s Eighth Amendment jurisprudence.73×73. To prove intellectual disability under Florida law, a defendant must show “significantly subaverage general intellectual functioning existing concurrently with deficits in adaptive behavior and manifested during the period from conception to age 18.”21×21. 12.

. Atkins v. Virginia, 536 U. S., at 321. To illustrate the use of two SEMs, let us hypothesize a case in which the defendant's obtained score is 74. . James P. Driscoll, Inc., v. Gould, 521 So.2d 301, 302 (Fla. 3d DCA 1988) (citing Turner ). The ABA contends that the threat of unfairness based on the inconsistency of mental retardation definitions undermines the procedural protections for mentally retarded defendants. These materials are based on federal disability rights laws and court decisions in effect at the time of publication. that the person's actual functioning is comparable to that of individuals with a lower IQ score"). 2013). Under this logic, all manner of outlier practices could become assailable.96×96. The legal determination of intellectual disability is distinct from a medical diagnosis, but it is informed by the medical community's diagnostic framework.

Because I find no consensus among the States, I would not independently assess the method that Florida has adopted for determining intellectual disability. Additionally, it defines significant sub-average intellectual functioning as “performance that is two or more standard deviations from the mean score on a standardized intelligence test.” The IQ test, which is used in this case, has a mean test score of 100 with a standard deviation of 15. See AAIDD 11th ed. Subsequently, the Florida Supreme Court construed Florida’s criminal code to bar any person with an IQ over 70 from offering evidence of intellectual disability.4×4. . Florida's rule disregards established medical practice in two interrelated ways. The Court's reliance on the views of professional associations will also lead to serious practical problems. 16-19.

Fla. Stat. and yet the Court has not in recent years entertained challenges to its constitutionality on that basis,102×102. See id., at 308, n. 3; DSM-5, at 33; Brief for American Psychological Association et al. Atkins, 536 U.S. at 317 (alteration in original) (quoting Ford v. Wainwright, 477 U.S. 399, 416–17 (1986) (opinion of Marshall, J.)) . . These organizations might recommend examining evidence of adaptive behavior even when an IQ is above 70, but that sheds no light on what the legal rule should be given that most States appear to require defendants to prove each prong separately by a preponderance of the evidence.

See id. 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. North Carolina's statute may allow for an unconstitutionally strict interpretation also, as it lists an IQ score of 70 or below directly within its requirements, but its courts have not yet considered this issue. Because these scores were above the mental retardation cutoff of 70 used in Florida, the court denied Hall’s motion to vacate the death sentence. Id., at 480. Of critical importance, there is not a single, uniform SEM across IQ tests or even across test-takers.

Afterward, Hall and Ruffin drove to a convenience store they planned to rob. Id., at 490.

at §14-753(K)(5).

The Florida Supreme Court affirmed the sentence, Hall v. State, 614 So. His lawyer in that matter later testified that the lawyer "[c]ouldn't really understand anything [Hall] said." is statutorily defined as “performance that is two or more standard deviations from the mean score on a standardized intelligence test.”23×23. Court, 503 U.S. 653, 657–58 (1992) (Stevens, J., dissenting) (cyanide gas). The Supreme Court reversed.31×31. 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." This comment uses the latter term to reflect the Court’s currently preferred terminology. At most, nine States mandate a strict IQ score cutoff at 70. 107-108. Hall received a death sentence, which the Florida Supreme Court affirmed.10×10. Florida counters that the state retains discretion in how it implements Atkins, and that they have properly applied those procedures to Hall. Case No. To begin, in addition to the 8 other States that the Court recognizes as having rules similar to Florida's, 1 more, Idaho, does not appear to require courts to take the SEM into account in rejecting a claim of intellectual disability.4 And of the remaining 21 States with the death penalty, 9 have either said nothing about the SEM or have not clarified whether they require its use.5 Accordingly, of the death-penalty states, 10 (including Florida) do not require that the SEM be taken into account, 12 consider the SEM, and 9 have not taken a definitive position on this question. Id. Id. In determining whether Florida's intellectual disability definition implements these principles and Atkins' holding, it is proper to consider the psychiatric and professional studies that elaborate on the purpose and meaning of IQ scores and how the scores relate to Atkins, and to consider how the several States have implemented Atkins. Code Ann. Freddie Lee Hall was tried, convicted, and sentenced to death for the 1978 murder of Karol Hurst.

Id.

36.

2d 473, 480 (Fla. 1993) (Barkett, C. J., dissenting).

No consensus exists among States or medical practitioners about what facts are most critical in analyzing that factor, and its measurement relies largely on subjective judgments. Thus, the court denied relief.30×30. Finally, relying primarily on proof of adaptive deficits will produce inequities in the administration of capital punishment. 2014) (no IQ cutoff); Idaho Code §19-2515A (Lexis Supp. §3-901 et seq. 481 U.S. 393 (1987).