The previous code, which took effect in 1980, distinguished among four culpable mental states according to whether the person acted intentionally, knowingly, recklessly, or negligently. The code also distinguished between three aspects of offenses to which these culpable mental states applied: (1) the nature of the conduct, (2) the circumstances surrounding the conduct, and (3) the result of the conduct. The 1982 amendments addressed the diminished capacity issue, the insanity defense, and the commitment procedures following an insanity verdict. They also added a new concept, guilty but mentally ill. The standards for release of defendants found not guilty by reason of insanity are extremely stringent. As a result, the number of defendants who try to plead guilty in any of its forms has dropped sharply, and no insanity pleas have been successful. The revisions to the law are unusually thorough, sophisticated, consistent, and well explained. The law's constitutionality has not yet been challenged. Five references.