MENTAL INCAPACITY DEFENSE IN ANGLO-AMERICAN LAW AND THE DEFENDANT’S ABILITY TO APPRECIATE CRIMINALITY OF HIS CONDUCT

Abstract

The purpose of this study is to provide a more complete account of the significant judicial innovations in the handling of family murder cases, with comparable interest in the subject of insanity defense. In order to analyze the determinants of reactions to the trials, the author also explored American federal and State law concerning the verdicts. Although the M’Naghten Rule was the dominant test, after the publication of the Model Penal Code, every American state that seriously considered incapacity defense reform legislatively or judicially adopted the MPC test. According to 18 U. S. C. §17, a federal defendant has had to prove that the “severe” mental disease made him “unable to appreciate the nature and quality or the wrongfulness of his acts”. Until 2020, state supreme courts disagreed on the constitutionality of abolishing the insanity defense. Several states had abolished or attempted to abolish the traditional, affirmative insanity defense and replaced it with a mens rea approach. The United States Supreme Court ruled that the Due Process Clause of the Fourteenth Amendment does not require the States to adopt an insanity defense based on a defendant’s ability to understand that his crime was morally wrong.