The Turnabout in the Insanity Defense

The Turnabout in the Insanity Defense For over a century the dominant test of legal insanity in the United States was that set out by the English judges in Daniel M'Naghten's case in 1843, under which it must be "clearly proved that, at the time of the committing of the act, the party accused was laboring under such a defect of reason, from disease of the mind, as not to know the nature and qual-ity of the act he was doing; or if he did know it, that he did not know he was doing what was wrong. " In the 1950s, two competing formulas emerged: the "Durham " test-under which criminal conduct is excused when it is the "product " of mental disease or defect-and the American Law Institute's Model Penal Code. By the early 1980s, the Model Code formula, which excused a defendant if he lacked substantial capacity to control his own behavior, had been adopted in a majority of America