Insanity

The law recognizes the mental state of the offender as important in a criminal defense. Criminal law holds people accountable for their behavior and responsible for a crime unless they have acted under severe and external duress (e.g., in self-defense, with a gun pointed at the head of the person) or they have a serious defect of rationality (i.e., being unable to distinguish right from wrong). The Model Penal Code requires the capacity for rationality: The defendant must be proved to have committed the crime while having a guilty state of mind. The physical elements that constitute a crime are called the actus reus (guilty act). The accompanied mental state is mens rea (guilty mind).

Under the McNaughton Rule, every person is to be presumed to ...