The Insanity Defense in Criminal Law

Abstract

The insanity defense in criminal law is an important aspect of the discussion of premenstrual syndrome (PMS) because some criminal cases have utilized premenstrual syndrome as a defense to criminal responsibility. Does PMS lead to insanity? Can, or should, PMS be utilized as the basis for an insanity defense in criminal matters? Insanity cannot be equated with mental illness. Insanity is a legal concept exculpating (i.e., excusing) from criminal responsibility an individual whose mental illness at the time of the alleged criminal act led to a particular state of mind consistent with the test of criminal insanity in that particular jurisdiction. The definition of insanity has varied from one jurisdiction to another. Furthermore, since the Hinckley trial in 1982 (discussed below), changes in the insanity defense have occurred throughout the country, and the standard continues to evolve. Insanity negates the mens rea or guilty intent portion of criminal behavior which always consists of both the act (actus reus) and the intent (mens rea).