Supreme Court Overturns Texas’ ​“Outlier” Standard for Determining Intellectual Disability in Capital Cases

The U.S. Supreme Court has unanimously struck down Texas’ standard for evaluating intellectual disability in death penalty cases, calling the state’s approach an “outlier” that, “[b]y design and in operation, … create[s] an unacceptable risk that persons with intellectual disability will be executed.”

In Moore v. Texas, the Court on March 28 vacated the judgment of the Texas Court of Criminal Appeals (CCA), which had applied an unscientific set of lay stereotypes known as the “Briseño factors” (named after the Texas court decision that announced them) to overturn a trial court determination that Texas death-row prisoner Bobby Moore was intellectually disabled. The Court described these seven factors—including such things as whether lay people who knew the defendant thought he was intellectually disabled and whether he could hide facts or lie effectively—as an unscientific “invention” of the CCA that was “untied to any acknowledged source” and that lacked support from “any authority, medical or judicial.”

The Supreme Court ruled in 2002, in Atkins v. Virginia, that the execution of individuals with intellectual disability was unconstitutional, but it left states with some discretion in determining who was intellectually disabled. However, as Justice Ruth Bader Ginsburg, writing for the five-justice majority, reiterated, “States’ discretion … is not unfettered.” “[A] court’s intellectual disability determination,” she wrote must be “informed by the medical community’s diagnostic framework.”

The Moore decision is the second time in recent years that the Court has addressed state deviations from clinical definitions of intellectual disability, which focus on “three core elements: (1) intellectual-functioning deficits, (2) adaptive deficits, and (3) the onset of these deficits while still a minor.” The Court struck down Florida’s use of a strict IQ cutoff in the 2014 case Hall v. Florida, noting that Florida’s standard, “disregards established medical practice.” The Hall decision addressed the first element, intellectual-functioning, while Moore addressed aspects of both the first and second, adaptive deficits. Chief Justice John Roberts and Associate Justices Samuel Alito and Clarence Thomas dissented from the portion of the Court’s opinion that held that Texas had inappropriately rejected Moore’s evidence of the first prong, deficits in intellectual functioning. But they joined the Court in rejecting Texas’ use of the Briseño factors, calling it “an unacceptable method of enforcing the guarantee of Atkins.”

The Court said that, “[i]n concluding that Moore did not suffer significant adaptive deficits, the CCA overemphasized Moore’s perceived adaptive strengths,” but “the medical community focuses the adaptive-functioning inquiry on adaptive deficits.” The Court ruled that Texas also had improperly required Moore to show that his deficits in functioning were unrelated to his traumatic upbringing and personality disorder. Traumatic exposures, the Court wrote, “count in the medical community as ‘risk factors’ for intellectual disability.” Further, the Court said, persons with intellectual disability may have other co-existing mental impairments and the existence of other mental-health issues are “not evidence that a person does not also have intellectual disability.”

Read the ruling here.