Maine Insanity [18 U.S.C. Sec. 17] is a legal concept that provides an affirmative defense to criminal charges in the state of Maine. The defense is based on the principle that the defendant, at the time of the commission of the crime, was unable to appreciate the wrongfulness of their conduct due to a mental disorder or defect. This means that the defendant was unable to understand the nature and quality of his/her act, or to distinguish right from wrong. Maine Insanity [18 U.S.C. Sec. 17] is divided into two distinct types: (1) Legal Insanity, and (2) Factual Insanity. Legal Insanity, also known as the M'Heighten Rule, is based on a defendant's inability to understand the wrongfulness of their conduct due to a mental disorder or defect. Factual Insanity is based on a defendant's inability to control their behavior due to a mental disorder or defect. In order to succeed with a defense of Maine Insanity [18 U.S.C. Sec. 17], the defendant must prove that they did not have the mental capacity to form the intent necessary to commit the crime.