Insanity Defense Reform Act: Redefining Acquittal Based on Insanity

One rationale for the century-old concept of an “insanity defense” has been that some accused criminals cannot appreciate the immorality of their crimes due to mental illness or disability, and should therefore not be held criminally responsible for such crimes. Critics of the insanity defense have expressed skepticism of the reality and extent of such claimed mental illnesses, and fear that criminals may sometimes escape just punishment. The determination as to whether a defendant is legally “insane” is usually based on expert testimony.

The Progression of the Insanity Defense

In 1843 Victorian England a man named M’Naghten was placed on trial for murdering a prime minister’s secretary, but was acquitted based on a defense of insanity. The public outrage over the acquittal led to the “M’Naghten Rule.” Under the M’Naghten Rule, an individual is insane if, at the time the act was committed, the individual could not distinguish right from wrong and therefore committed the crime without knowing such actions were wrong. The intent of the M’Naghten Rule was to require individuals claiming insanity to demonstrate specific characteristics of mental incapacity. The M’Naghten Rule made it more difficult for defendants to validly establish “insanity” as a defense.

Another common test for insanity applied in some states is the “Irresistible Impulse Test.” This test expanded the M’Naghten Rule to extend the defense to situations where the individual realized that his actions were wrong, but still could not control his conduct. Most states, however, abandoned this rule in favor of the Federal Insanity Defense Reform Act of 1984 (IDRA).

The Insanity Defense Reform Act of 1984

When John Hinckley attempted to assassinate President Reagan, he successfully used an insanity defense which resulted in his incarceration at St. Elizabeth’s mental institution, instead of prison. In the aftermath of this result, the federal government enacted the IDRA. The following list specifies notable elements of IDRA:

Makes insanity an affirmative defense
Mandates that the accused must not “appreciate the nature and quality or the wrongfulness of his acts” because of a severe mental disease or defect
Places the burden of proof on the defendant by “clear and convincing evidence”
Limits the scope of expert testimony on material issues
Eliminates the defense of diminished capacity, i.e., mental disease or defect does not otherwise constitute a defense
Implicitly eliminates use of alcohol or drugs as a valid affirmative defense
Creates a special verdict of “not guilty by reason of insanity” (NGRI), which triggers a commitment proceeding
Provides for commitment of persons who become insane while serving a federal prison term
Effectively eliminates the “Irresistible Impulse Test”

Statistics show that the insanity defense is seldom used or successful. An NGRI verdict often leads to more time in an institution than the accused would likely have spent in prison if convicted. An unsuccessful attempt at pleading NGRI may lead to a longer sentence than if the insanity defense was not used.

Asserting a Valid Insanity Defense

Legal requirements for establishing a valid insanity defense vary by state. Many states require the criminal to establish himself as more likely insane than not. Several states also hold that any “voluntary act” by the criminal eliminates the insanity defense. The following is a sample of the relevant statutes from Texas, New Jersey and Utah setting forth the requirements for a valid insanity defense:

The Texas statute states that “it is an affirmative defense to prosecution that, at the time of the conduct charged, the actor, as a result of severe mental disease or defect, did not know that his conduct was wrong … The term ‘mental disease or defect’ does not include an abnormality manifested only be repeated criminal or otherwise antisocial behavior.”

In New Jersey, a person “is not criminally responsible for conduct if at the time of such conduct he was laboring under such a defect of reason, from disease of the mind as not to know the nature and quality of the act he was doing, or if he did know it, that he did not know what he was doing was wrong.” For certain crimes, establishing the element of “intent” is crucial in proving culpability. In light of this principle, subsequent language in the New Jersey “defense by insanity” takes on additional importance. Specifically, defendants are permitted to provide evidence of “mental disease or defect … whenever it is relevant to prove that the defendant did not have a state of mind which is an element of the offense.”

In Utah “it is a defense to a prosecution under any statute or ordinance that the defendant, as a result of mental illness, lacked the mental state required as an element of the offense charged … ‘Mental illness’ means a mental disease or defect that substantially impairs a person’s mental, emotional, or behavioral functioning. A mental defect may be a congenital condition, the result of injury, or a residual effect of a physical or mental disease and includes, but is not limited to mental retardation.” Similar to the Texas statute, Utah specifically precludes defendants from asserting insanity as a defense for any “abnormality manifested primarily by repeated criminal conduct.”