United States Supreme Court

Intellectual Disability Supreme Court Cases

Atkins v. Virginia

On June 20, 2002, the Supreme Court issued a landmark ruling ending the death penalty for individuals with intellectual disability. In Atkins v. Virginia, the Court held that it is a violation of the Eighth Amendment ban on cruel unusual punishment to execute death row inmates with “mental retardation”. The decision reflects the national consensus which has formed on this issue. (Associated Press, June 20, 2002).

Read the opinion. See also DPIC’s Press Release.

In 1989, the U.S. Supreme Court had upheld (5-4) the constitutionality of executing those with intellectual disability in Penry v. Lynaugh (492 U.S. 302). The Court said “mental retardation” should be a mitigating factor to be considered by the jury during sentencing. Writing for the majority, Justice Sandra Day O’Connor said that a “national consensus” had not developed against executing those with “mental retardation.”

At the time, only two states, Maryland and Georgia, prohibited such executions. Between the Penry and Atkinsdecisions, 16 additional states enacted laws prohibiting the execution of the “mentally retarded.” The federal death penalty statute also forbids such executions. Prior to Atkins v. Virginia, eighteen states plus the federal government did not allow the execution of those with “mental retardation”: AZ, AR, CO, CT, FL, GA, IN, KS, KY, MD, MO, NE, NM, NY*, NC, SD, TN, WA, and U.S. (*except for murder by a prisoner) Read summaries of the states’ criteria for establishing and defining “mental retardation.

See also Professor James Ellis’s model legislation and explanation for states to comply with the Atkins ruling: “Mental Retardation and the Death Penalty: A Guide to State Legislative Issues.” Mental health experts have pointed out that those with intellectual disability are characterized by suggestibility and their willingness to please can lead them to confess - sometimes falsely - to capital crimes. In 1989, the American Bar Association established a policy opposing the execution of those with “mental retardation.” The ABA held that execution of such individuals is unacceptable in a civilized society, irrespective of their guilt or innocence. In 1997, the continued imposition of the death penalty on those with intellectual disability and on juveniles contributed to the ABA’s call for a nationwide moratorium on the death penalty.

Hall v. Florida

On May 27, 2014, the U.S. Supreme Court held in Hall v. Florida that Florida’s strict IQ cutoff for determining intellectual disability in capital cases is unconstitutional. The Court found that “Florida’s law contravenes our Nation’s commitment to dignity and its duty to teach human decency as the mark of a civilized world.” In 2002, when the Court in Atkins banned the execution of people with “mental retardation,” it allowed states leeway in selecting a process for determining who would qualify for that exemption. According to Florida’s Supreme Court, defendants with an IQ even one point above 70 cannot be considered intellectually disabled, even though most states allow for a margin of error in such tests. The Supreme Court’s ruling stated that Florida’s strict rule “disregards established medical practice” and noted that the “vast majority of states” rejected such a narrow interpretation of IQ scores. The Court held 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.” Hall will receive a new hearing on his intellectual disability claim.

Read the opinion.

See also Professor James Ellis’s research paper, “Hall v. Florida: The Supreme Court’s Guidance in Implementing Atkins” (James W. Ellis, William & Mary Bill of Rights Journal, 2014)

Moore v. Texas

On March 28, 2017, in Moore v. Texas, the Supreme Court struck down Texas’s standard for evaluating intellectual disability in death penalty cases, calling the state’s approach to reviewing an individual’s deficits in adaptive functioning an “outlier” that, “[b]y design and in operation, … create[s] an unacceptable risk that persons with intellectual disability will be executed.” The Court granted relief to Petitioner Bobby James Moore, holding that Texas’ use of non-scientific factors to determine whether a person is ineligible for the death penalty because of intellectual disability is “irreconcilable” with the Court’s precedent and with the Eighth Amendment. The Court said that although states have discretion in how they enforce the constitutional prohibition against applying the death penalty to persons who are intellectually disabled, that discretion is not “unfettered.” When determining whether someone is intellectually disabled, the Court rejected Texas’ approach because it is not “informed by the medical community’s diagnostic framework.” Texas adopted criteria for determining intellectual disability that critics and mental health advocates say would merely perpetuate stereotypes and that had no basis in medical literature. For example, the fact-finder must consider whether people who knew the person during childhood, such as family, friends, teachers, employers, authorities, “th[ought] he was mentally retarded.” Other questions also included whether he formulated plans, whether his conduct responsive to external stimuli is rational and appropriate, whether he responds coherently and rationally in response to questions, and whether he could lie in his own or others’ interests. Some of the factors are based upon the characteristics of the fictional character Lennie Smalls from John Steinbeck’s novel, Of Mice and Men. The Supreme Court found that this was an unscientific “invention” of the Texas court that was “untied to any acknowledged source” and that it lacked support from “any authority, medical or judicial.”

Read the opinion.

Moore v. Texas II

On remand, the Harris County Prosecutor’s Office agreed that Moore had proven his intellectual disability. However, the Texas Court of Criminal Appeals again concluded that Moore had not proven significant deficits in adaptive functioning. Moore sought review of this decision in the US Supreme Court. In Moore v. Texas, No. 18-443, the Supreme Court issued a per curiam opinion reversing the Texas Court of Criminal Appeals’ denial of Bobby James Moore’s claim that intellectual disability rendered him ineligible for the death penalty. The Supreme Court found that though the Texas court claimed to have abandoned the Briseno factors, it continued to overemphasize Moore’s adaptive strengths, rely upon his behavior in prison, speculate on the source of adaptive deficits, and base conclusions on stereotypes about individuals with intellectual disability. The Supreme Court “agree[d] with Moore and the prosecutor that, on the basis of the trial court record, Moore has shown he is a person with intellectual disability.”