Before and After Hinckley: Legal Insanity in the United States

Document Type

Book Chapter

Publication Date



This chapter first considers the direction of the affirmative defense of legal insanity in the United States before John Hinckley was acquitted by reason of insanity in 1982 for attempting to assassinate President Reagan and others and the immediate aftermath of that acquittal. Since the middle of the 20th Century, the tale is one of the rise and fall of the American Law Institute’s Model Penal Code test for legal insanity. Then it turns to the constitutional decisions of the United States Supreme Court concerning the status of legal insanity. Finally, it addresses the substantive and procedural changes that have occurred in the insanity defense since the wave of legal changes following the Hinckley decision.


Criminal law & procedure, psychology, legal history, mens rea, insanity defense, mental disorder, Model Penal Code, MPC, M’Naghten test, production & persuasion burden, cognitive & control tests, Supreme Court of the United States, SCOTUS, civil commitment

Publication Title

The Insanity Defence: International and Comparative Perspectives

Publication Citation

In The Insanity Defence: International and Comparative Perspectives (Ronnie Mackay & Warren Brookbanks eds., Oxford, forthcoming 2022)