The "Insanity Plea" is a legal defense used in criminal cases where a defendant claims they were not mentally capable of understanding their actions at the time of the crime. This plea is based on the idea that individuals who are mentally ill may not be fully responsible for their behavior, as they cannot distinguish right from wrong. If a defendant successfully uses the insanity plea, they may be found not guilty by reason of insanity. Instead of serving time in prison, they might be committed to a mental health facility for treatment. The criteria for this plea can vary by jurisdiction, often involving evaluations by mental health professionals.