Not Guilty By Reason of Insanity (NGRI)

Not guilty by reason of insanity (NGRI) is a verdict issued in criminal cases whereby the defendant, determined to be legally insane, is held not responsible for his or her criminal actions. NGRI is a possible verdict following trials in which the defendant employs the “insanity defense,” arguing that the criminal behavior in question was caused by a mental disorder that existed at the time of the offense. Unlike a plea of “Not guilty,” a defendant entering a plea of insanity is admitting to the acts and harms alleged by the prosecution but claiming that he or she should not be held criminally responsible for such acts and harms. Also unlike a “Not guilty” verdict, a finding of NGRI is not an acquittal. Rather, defendants judged to have been legally insane at the time of the offense and subsequently found NGRI are in almost all cases indefinitely committed to psychiatric hospitals for treatment.

Although the insanity defense became popularized in light of media attention to and public fascination with its use in high-profile cases (e.g., John Hinckley Jr., Jeffrey Dahmer, Ted Kaczynski), it is rarely employed and even more rarely successful in cases involving homicide or other violent crime. Nevertheless, questions concerning a defendant's mental state at the time of the offense are occasionally raised in criminal trials or prior to criminal trials during the course of the plea-bargaining process. Because NGRI remains a possible verdict and insanity a possible criminal defense in almost all states, it is important to understand the rationale and relevant legal issues, and clarify several common misconceptions.