Assessment of Intellectual Disability in Death Penalty Cases

The U.S. Supreme Court’s opinion in Hamm v. Smith addressed the assessment of intellectual disability in capital cases, focusing on how courts should evaluate multiple full-scale IQ scores in claims arising under Atkins v. Virginia, which barred the death penalty for defendants with intellectual disabilities. Although the court declined to establish a clear framework for weighing conflicting psychometric evidence, the decision highlights principles of psychological assessment that are frequently misunderstood in legal proceedings. This column examines the legal and psychometric issues presented in Hamm and discusses implications for future litigation involving the assessment of intellectual disability in capital cases.