• Unlike other defenses, a successful insanity defense may not result in in acquittal but instead in a special verdict (“not guilty by reason of insanity”) that usu. leads to the defendant’s commitment to a mental institution.
— Also termed insanity plea. See MCNAGHTEN RULES; SUBSTANTIAL-CAPACITY TEST; IRRESISTIBLE-IMPULSE TEST; DURHAM RULE; APPRECIATION TEST. [Cases: Criminal Law 47; Homicide 817.C.J.S. Criminal Law §§ 99–108.]