Assessing mental retardation in death penalty cases: Critical issues for psychology and psychological practice

In 2002, the United States Supreme Court decided the Atkins case, which held that mentally retarded defendants could not be executed. The opinion gave no guidance on the definition of mental retardation, preferring to leave to individual states the task of determining not only the definition of mental retardation but also the assessment procedures to be used in making the diagnosis. This lack of guidance has resulted in many issues, including varying definitions of what constitutes mental retardation across states, use of different assessment procedures to make the determination that a person has mental retardation, and numerous psychometric concerns regarding the provision of psychological assessment services to the courts in capital cases that involve a defendant who may have mental retardation. This article examines these latter issues in detail from both psychological and legal perspectives and makes recommendations for practicing psychologists.