Moore v. Texas: The Supreme Court Presses States to Comport with the Evolving Medical Understanding of Intellectual Disability

Last week, the Supreme Court of the United States decided Moore v. Texas, the third major case the Court has decided about intellectual disability (formerly, mental retardation) and the death penalty. This post summarizes the case and considers its impact on North Carolina.

Background. In 1980, Moore and two other men decided to rob a grocery store. Shortly after they entered, Moore shot a clerk in the head and the men fled. Moore was apprehended, charged with capital murder, convicted, and sentenced to death.

He later alleged that he was intellectually disabled and so ineligible for the death penalty under Atkins v. Virginia, 536 U.S. 304 (2002) (ruling that the Eighth Amendment precludes the execution of the intellectually disabled) and its progeny. A state habeas court agreed, applying the criteria that are currently used in the mental health community, such as those contained in the AAIDD-11, a manual published by the American Association on Intellectual and Developmental Disabilities, and the DSM-V. Those standards require an IQ score of approximately 70 or below, accounting for measurement error; “adaptive deficits”; and onset before age 18. The court credited six IQ tests, with an average score of 70.66, and, relying on expert testimony, found that Moore suffered adaptive deficits in each of three areas recognized in the literature: conceptual, social, and practical functioning.

The Texas Court of Criminal Appeals ruled otherwise, concluding that precedent required the lower court to apply the intellectual disability standards set forth in Ex parte Briseno, 135 S.W. 3d 1 (Tex. Crim. App. 2004). Those standards were based partly on the AAMR-9, the 1992 predecessor to the AAIDD-11, and included seven factors that the Briseno court seemed to have developed on its own, such as whether the person formulates and carries out plans, and whether the person responds “coherently, rationally, and on point” to questions. Applying those standards, the court first found insufficient evidence of significantly subaverage general intellectual functioning. It discounted several of Moore’s IQ tests because they were group-administered or otherwise unreliable. The two remaining scores were 74 and 78. As to the 74, the court suggested that it might understate Moore’s intelligence because Moore was depressed and not motivated when he took the test. Then the court turned to adaptive functioning. It found that while Moore had deficits in some areas of adaptive functioning, these were offset by strengths in other areas such as his ability to live on the streets and his ability to earn money by mowing lawns.

The majority opinion. The Supreme Court of the United States reversed. Justice Ginsburg wrote the majority opinion, joined by the Court’s other three liberal Justices and by Justice Kennedy. Some of the Court’s key points were:

  • Without specifically resolving which IQ tests should be considered, the Court described Moore as having an IQ “score of 74” which, “adjusted for the standard error of measurement, yields a range of 69 to 79.” Because part of that range is under 70, Hall v. Florida, __ U.S. __, 134 S.Ct. 1986 (2014) (discussed here; holding that states may not define intellectual disability in a way that categorically excludes defendants with IQ test results above 70 in light of the risk of measurement error), requires a court to “move on to consider Moore’s adaptive functioning.”
  • Because the relevant current clinical guides focus on adaptive deficits, not strengths, the Texas court erred in allowing strengths in one area to offset deficits in another.
  • The lower court’s reliance on the Briseno factors was improper. These “lay perceptions of intellectual disability” were mere “stereotypes” not grounded in medical or scientific reality.
  • Overall, states have “some flexibility” in implementing Atkins, but not “unfettered discretion.” Specifically, the “medical community’s current standards supply one constraint on States’ leeway.”


The dissent. Chief Justice Roberts dissented, joined by Justices Thomas and Alito. The dissenters viewed the matter as follows:

  • The dissent agreed that the Briseno factors “are an unacceptable method of enforcing the guarantee of Atkins,” and acknowledged that the consideration of those factors might have tainted the lower court’s determination regarding adaptive deficits.
  • However, the dissent saw the Texas court’s determination regarding general intellectual functioning as reasonable and as an independent ground for denying relief. The Texas court expressly considered the possibility of measurement error — as Hall requires — and explained why it thought that Moore’s true intelligence was not likely to be at the lower end of the range implied by his test result of 74.
  • More generally, the dissent criticized the majority for relying on current medical and clinical literature so heavily. In determining the scope of the Eighth Amendment, the dissent viewed the proper reference point as being society’s consensus about what constitutes unjustified punishment, as reflected in the actions of state legislatures: “The Eighth Amendment, under our precedent, is supposed to impose a moral backstop on punishment, prohibiting sentences that our society deems repugnant. The Court, however, interprets that constitutional guarantee as turning on clinical guidelines that do not purport to reflect standards of decency.“


Analysis and impact on North Carolina. In some ways, the emphasis on clinical standards that is a bone of contention in Moore was forecast by Hall. Still, Moore does highlight some important questions that may be explored in further litigation. (1) The majority insists that states retain some discretion in defining intellectual disability. But what leeway do they have, if they must follow the current versions of the AAIDD and the DSM? Do those documents simply define a floor, such that states are free to define intellectual disability more broadly, but not more narrowly? (2) Does the majority’s reasoning mean that any defendant with an IQ score of 74 or under has satisfied the general intellectual functioning prong, or does such a score merely raise a colorable question about that prong that might be debated further? Does Moore mean that a single test result of 74 or below is dispositive even if other test results are higher? (3) Is the margin of measurement error always +/- 5 points, even if a defendant has taken multiple valid tests?
North Carolina’s statute regarding intellectual disability, G.S. 15A-2005, was first enacted in 2001. It was revised in 2015, in response to Hall, and those revisions reduce the impact of Moore by incorporating current clinical standards. Specifically, the statute already provides that “[a]ccepted clinical standards for diagnosing significant limitations in intellectual functioning and adaptive behavior shall be applied in the determination of intellectual disability.”

3 thoughts on “Moore v. Texas: The Supreme Court Presses States to Comport with the Evolving Medical Understanding of Intellectual Disability”

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.