Television shows often promote the idea of an insanity defense as a way to beat criminal charges. While this is a valid defense, just about one percent of court cases across the nation rely on this defense.
The meaning of insanity is different in the legal world, as it is not a medical term under criminal law. This impacts how the defense of an individual moves forward.
Legal vs psychological definitions
As a medical term, the word insanity refers to a severe mental illness that keeps an individual from separating reality from fantasy, propels him or her to uncontrollable, impulsive behavior and creates conditions of psychosis. Under the legal definition, insanity does not always indicate mental illness. In the state, a defense of insanity must demonstrate that there was a significant impact on the mind of the offender from a mental disease or defect. This impact affected the behavior to such an extent that a crime occurred.
Under the state legislature, there are several requirements for arguing insanity. These include:
- The individual had the inability to perceive the quality and nature of the offense concerning the charge
- The individual could not tell right from wrong for the charged offense
- A preponderance of the evidence must support a defense of insanity
In many cases, a defendant must complete a mental evaluation when using an insanity defense. The defense could also require professional testimony from a psychologist or psychiatrist.
An individual can have no prior history of mental illness before the act and still use a plea of insanity. The court, whether judge or jury, ultimately determines a fining of criminal insanity.