The Federal Insanity Defense Reform Act


The federal Insanity Defense Reform Act of 1984, codified at 18 U.S.C. ยง 17, provides: “It is an affirmative defense to a prosecution under any Federal statute that, at the time of the commission of the acts constituting the offense, the defendant, as a result of a severe mental disease or defect, was unable to appreciate the nature and quality of the wrongfulness of his acts. Mental disease or defect does not otherwise constitute a defense.” This act, a response to the Hinckley verdict, eliminated the Irresistible Impulse Test from the insanity defense under federal law. The act also provided that “the defendant has the burden of proving the defense of insanity by clear and convincing evidence.” Previously under federal law, the government had the burden of proving sanity.