In the United States of America, the federal government and several states have historically attempted to impose the death penalty on intellectually disabled criminal defendants who committed intentional homicide. It was not until 2002 in the case of Atkins v. Virginia, where the United States Supreme Court held that capital defendants who possessed intellectual disability could not face capital punishment. This entry highlights the evolution of the use of the death penalty as punishment for individuals with intellectual disabilities, reporting on current judicial precedent controlling the issue in the United States of America. In addition, the entry discusses these issues by focusing on two recent cases decided by the United States Circuit Courts of Appeals, which are the appellate courts directly below the United States Supreme Court. The entry concludes with a discussion on how to better protect the rights of individuals with intellectual disabilities within the criminal justice system.