Insanity Defense
| Author | Jeffrey Wilson |
| Pages | 485-490 |
Page 485
Although the insanity defense is probably the most controversial of all criminal defense strategies, it is also, somewhat ironically, one of the least used. On many occasions when it has been used, particularly in the much-publicized 1984 acquittal of John W. Hinckley, Jr. for the attempted assassination of President Ronald Reagan, the insanity defense has tended to provoke public debate.
The insanity defense asserts that a criminal defendant should not be found guilty due to the defendant's insanity. The theory behind the defense is that a person who is insane lacks the intent required to perform a criminal act because the person either does not know that the act is wrong or cannot control his or her actions even when the person understands that the act is wrong. This theory is controversial because insanity itself is difficult to define, and the circumstances in which insanity can be used to excuse criminal responsibility are difficult to characterize.
The insanity defense has existed since the twelfth century, but initially it was not considered an argument for the defendant to be found not guilty. Instead, it was a way for a defendant to receive a pardon or a way to mitigate a sentence. The idea that insanity could bar the conviction of a defendant arose in the early nineteenth century in The Medical Jurisprudence of Insanity by an influential scholar named Isaac Ray, as well as in the seminal decision in England called the M'Naghten case.
In 1843, Daniel M'Naghten, an Englishmen who was apparently a paranoid schizophrenic under the delusion that he was being persecuted, shot and killed Edward Drummond, Secretary to British Prime minister Sir Robert Peel. M'Naghten believed that Drummond was Peel. To the surprise of the nation, M'Naghten was found not guilty on the grounds that
Page 486
he was insane at the time of his act. The subsequent public outrage convinced the English House of Lords to establish standards for the defense of insanity, the result subsequently referred to as the M'Naghten Rule.
The M'Naghten Rule provides as follows: "Every man is to be presumed to be sane, and … that to establish a defense on the ground of insanity, it must be clearly proved that, at the time of the committing of the act, the party accused was laboring under such a defect of reason, from disease of mind, and not to know the nature and quality of the act he was doing; or if he did know it, that he did not know he was doing what was wrong."
The test to determine if a defendant can distinguish right from wrong is based on the idea that the defendant must know the difference in order to be convicted of a crime. Determining a defendant's ability to do so may seem straightforward enough, but dilemmas often arise in cases in which the M'Naghten standard is used. For instance, some issues focus on whether a defendant knew that his or her criminal acts were wrong or whether he or she knew that laws exist that prohibit these acts.
Criticism of the M'Naghten test often focuses on the test's concentration on a defendant's cognitive abilities. Questions also crop up about how to treat defendants who know their acts are against the law but who cannot control their impulses to commit them. Similarly, the courts need to determine how to evaluate and assign responsibility for emotional factors and compulsion. Additionally, because of the rule's inflexible cognitive standard, it tends to be difficult for defendants to be found not guilty by reason of insanity. Despite these complications, M'Naghten has survived and is currently the rule in a majority of states with regard to the insanity defense (sometimes combined with the Irresistible Impulse Test, discussed below).
In response to criticisms of the M'Naghten Rule, some legal commentators began to suggest expanding the definition of insanity to include more than a cognitive element. Such a test would encompass not only whether defendants know right from wrong but also whether they could control their impulses to commit wrong-doing. The Irresistible Impulse Test was first adopted by the Alabama Supreme Court in the 1887 case of Parsons v. State. The Alabama court stated that even though the defendant could tell right from wrong, he was subject to "the duress of such mental disease [that] he had … lost the power to choose between right and wrong" and that "his free agency was at the time destroyed," and thus, "the alleged crime was so connected with such mental disease, in the relation of cause and effect, as to have been the product of it solely." In so finding, the court assigned responsibility for the crime to the mental illness despite the defendant's ability to distinguish right from wrong.
The Irresistible Impulse Test gained acceptance in various states as an appendage to the M'Naghten Rule, under which right versus wrong was still considered a vital part of any definition of insanity. In some cases, the Irresistible Impulse Test was considered to be a variation on M'Naghten; in others, it was considered to be a separate test. Though the Irresistible Impulse Test was considered to be an important corrective on M'Naghten's cognitive...
To continue reading
Request your trial