The jury's decision in John Hinckley's trial following his attempted assassination of President Reagan aroused controversy, protest, and a clamor for reform. However, an analysis of the history of the defense shows that its use is rare and largely noncontroversial. However, it receives enormous media attention, and the public is basically misinformed about its frequency of use. The response to the Hinckley decision has led to the enactment of a Federal statute on the legal criteria for the defense of insanity and of at least eight State laws defining verdicts of guilty but mentally ill. Future discussions of how to handle people who are mentally ill and violate the law should not discard the connection between responsibility and guilt and focus only on extracting revenge. 12 references.