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United States Insanity Defense

Criminal Laws - Insanity Defense - United States


Insanity Defense

Sections within this essay:

Background
The M'Naghten Rule
The Irresistible Impulse Test
The Durham Rule
The American Law Institute's Model Penal Code Test
The Hinckley Trial
Current Application of the Insanity Defense
Burden of Proof
Commitment and Release Procedures
Distinction Between the Insanity Defense and Competency to Stand Trial
The Federal Insanity Defense Reform Act
Guilty but Mentally Ill

Status of the Insanity Defense in Criminal Law
The Insanity Defense Among the States
Additional Resources
Organizations
American Bar Association Criminal Justice Section
American Psychological Association (APA)
Association of Federal Defense Attorneys

Background

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.

The M'Naghten Rule

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 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).

The Irresistible Impulse Test

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 bias, it still came under some criticism of its own. For example, it seemed to make the definition of insanity too broad, failing to take into account the impossibility of determining which acts were uncontrollable rather than merely uncontrolled, and also making it easier to fake insanity. The test was also criticized for being too narrow; like M'Naghten, the test seemed to exclude all but those totally unable to control their actions. Nevertheless, several states currently use this test along with the M'Naghten Rule to determine insanity, and the American Law Institute in its Model Penal Code definition of insanity adopted a modified version of it.

The Durham Rule

The Durham Rule, a version of which was originally adopted in New Hampshire in 1871, was embraced by the Circuit Court of Appeals for the District of Columbia in the 1954 case of Durham v. United States. The Durham Rule, sometimes referred to as the "product test," provides that the defendant is not "criminally responsible if his unlawful act is the product of a mental disease or defect."

The Durham Rule was originally seen as a way of simplifying the M'Naghten Rule and the Irresistible Impulse Test by making insanity and its relation to the crime a matter of objective diagnosis. Nevertheless, such a diagnosis proved to be more difficult to prove in practice than in theory. The test was criticized because the Circuit Court has provided no real definitions of "product," "mental disease," or "de-fect." Because the Durham Rule proved very difficult to apply, the Circuit Court abandoned it in 1972. Currently, only the state of New Hampshire still uses the Durham Rule as a way to define insanity.

The American Law Institute's Model Penal Code Test

In response to the criticisms of the various tests for the insanity defense, the American Law Institute (ALI) designed a new test for its Model Penal Code in 1962. Under this test, "a person is not responsible for criminal conduct if at the time of such conduct as a result of mental disease or defect he lacks substantial capacity either to appreciate the criminality of his conduct or to conform his conduct to the requirements of the law."

The Model Penal Code test is much broader than the M'Naghten Rule and the Irresistible Impulse Test. It asks whether defendants have a substantial incapacity to appreciate the criminality of their conduct or to conform their conduct to the law rather than the absolute knowledge required by M'Naghten and the absolute inability to control conduct required by the Irresistible Impulse Test.

The ALI test also requires that the mental disease or defect be a mental diagnosis. In this way, it manages to incorporate elements of all three of its predecessors: the knowledge of right and wrong required by M'Naghten, the prerequisite of lack of control in the Irresistible Impulse Test, and the diagnosis of mental disease and defect required by Durham.

Such a broad based rule received wide acceptance, and by 1982 all federal courts and a majority of state courts had adopted the ALI test. While some states have since dropped the ALI test, and it no longer applies at the federal level, 18 states still use the ALI test in their definitions of insanity.

The Hinckley Trial

In 1982, John W. Hinckley, who had attempted in 1981 to assassinate President Ronald Reagan, was acquitted of the crime by a District of Columbia court by reason of insanity. The enormous outrage after Hinckley's acquittal led three states to drop the insanity defense entirely (Montana, Utah, and Idaho, joined by a fourth, Kansas, in 1995). Other states reformed their insanity defense statutes, by adopting the M'Naghten standard over the Model Penal code standard, by shifting the burden of proof from the state to the defense, by changing their commitment and release procedures, or by adopting a "Guilty but Mentally Ill" defense. In addition, the federal courts shifted from the ALI standard to a new law eliminating the Irresistible Impulse Test for insanity defenses in federal crimes.

Current Application of the Insanity Defense

Burden of Proof

The question of who has the burden of proof with an insanity defense has been a source of controversy. Before the Hinckley verdict, a majority of states had the burden of proof rest with the state; that is, the prosecutor had to prove that the defendant was not insane. After the Hinckley verdict, the vast majority of states required the defense to prove that the defendant was indeed insane. In states where the burden is on the defense to prove insanity, the defense is required to show either by clear and convincing evidence or by a preponderance of the evidence that the defendant is insane. In states where the burden is still on prosecutors to prove sanity, they are required to prove it beyond a reasonable doubt.

Commitment and Release Procedures

Contrary to uninformed opinion, defendants found not guilty by reason of insanity are not simply released from custody. They are generally committed to mental hospitals where they can be confined for longer than their prison terms would have been. In the case of Jones v. United States, the Supreme Court in 1983 backed this proposition, ruling that the sentence that criminal defendants would have received had they been convicted should have no bearing on how long they could be committed to a mental hospital.

After Hinckley, many states changed their commitment policies to ensure that a defendant found not guilty by reason of insanity would be required to stay in a mental hospital for a certain period of time for evaluation following acquittal. Previously, no time was specified. Also, several states changed the burden of proof for release from the state to defendants.

Distinction Between the Insanity Defense and Competency to Stand Trial

All jurisdictions require that criminal defendants must be competent to stand trial, meaning that defendants understand the nature of the proceedings against them and are able to assist counsel in their defense. A person who is found to be mentally incompetent to stand trial is usually hospitalized for treatment until such time that the person is competent to stand trial. Competency does not address the guilt or innocence of a party, and so competency to stand trial should not be confused with the insanity defense.

The Federal Insanity Defense Reform Act

The federal Insanity Defense Reform Act of 1984, codified at 18 U.S.C. § 17, provides: "It is an affirmative defense to a prosecution under any Federal statute that, at the time of the commission of the acts constituting the offense, the defendant, as a result of a severe mental disease or defect, was unable to appreciate the nature and quality of the wrongfulness of his acts. Mental disease or defect does not otherwise constitute a defense." This act, a response to the Hinckley verdict, eliminated the Irresistible Impulse Test from the insanity defense under federal law. The act also provided that "the defendant has the burden of proving the defense of insanity by clear and convincing evidence." Previously under federal law, the government had the burden of proving sanity.

Guilty but Mentally Ill

Finally, the Hinckley verdict accelerated the adoption of "guilty but mentally ill" verdicts by states. The "guilty but mentally ill" verdict allows mentally ill defendants to be found criminally liable and requires them to receive psychiatric treatment while incarcerated, or, alternatively, to be placed in a mental hospital and then, when they are well enough, to be moved to a prison to serve their sentences. Laws allowing pleas and verdicts of guilty but mentally ill were first adopted in Michigan in 1975, and concurrent with or subsequent to the Hinckley trial were adopted by 12 more states.

Status of the Insanity Defense in Criminal Law

Commentators have noted that the insanity defense is risky for criminal defendants because it virtually eliminates any possibility that prosecutors will agree to a plea bargain. Studies, including an eight-state investigation by the National Institute of Mental Health, have shown that the insanity defense is raised in less than one percent of all felony cases. This defense is successful in only a fraction of those cases.

Nevertheless, when the insanity defense is raised, it continues to spur controversy. For instance, in 2001, Andrea Yates of Texas, who allegedly suffered from a mental illness, drown her five children in less than an hour. At her trial for capital murder, Yates' attorneys pleaded the insanity defense, arguing that she suffered post-partum depression. A jury rejected this argument and found her guilty. She received a life sentence for the murders.

The public showed great interest in the Yates trial. Some members of the public, especially but not limited to women's groups, sympathized with Yates due to her battle with post-partum depression. At her trial, four out of five psychiatrists and one psychologist testified that Yates did not know right from wrong. However, the single mental health expert called by the prosecution testified that Yates indeed knew right from wrong, and the jury eventually rejected her insanity defense. Facts later revealed that the state's expert had presented false testimony regarding Yates, and a Texas appellate court in 2005 reversed her conviction and ordered a new trial. Yates v. State, 171 S.W.3d 215 (Tex. App. 2005).

The Yates case demonstrates that in some instances the insanity defense can garner some support. Nevertheless, such a defense is still difficult to prove, and states have not made significant efforts to revise their versions of the insanity defense in recent years.

The Insanity Defense Among the States

Four states, including Kansas, Montana, Idaho, Utah, do not allow the insanity defense. In other states, the standards for proving this defense vary widely. The following provides the status of the insanity defense in each jurisdiction.

ALABAMA: The state uses the M'Naghten Rule. The burden of proof is on the defendant.

ALASKA: The state uses a modified version of the M'Naghten Rule. The burden of proof is on the defendant. A guilty but mentally ill verdict is allowed.

ARIZONA: The state uses a modified version of the M'Naghten Rule. The burden of proof is on the defendant. A guilty but insane verdict is allowed.

ARKANSAS: The state uses a modified version of the Model Penal Code rule. The burden of proof is on the defendant.

CALIFORNIA: The state uses the M'Naghten Rule. The burden of proof is on the defendant.

COLORADO: The state uses a modified version of the M'Naghten Rule with the Irresistible Impulse Test. The burden of proof is on the state.

CONNECTICUT: The state uses a modified version of the Model Penal Code rule. The burden of proof is on the defendant.

DELAWARE: The state uses a modified version of the Model Penal Code rule. The burden of proof is on the defendant.

DISTRICT OF COLUMBIA: The state uses the Model Penal Code rule. The burden of proof is on the defendant.

FLORIDA: The state uses the M'Naghten Rule. The burden of proof is on the state.

GEORGIA: The state uses a modified version of the M'Naghten Rule. The burden of proof is on the defendant. A guilty but mentally ill verdict is allowed.

HAWAII: The state uses the Model Penal Code rule. The burden of proof is on the defendant.

IDAHO: The state has abolished the insanity defense. The state allows a guilty but insane verdict.

ILLINOIS: The state uses a modified version of the Model Penal Code rule. The burden of proof is on the defendant.

INDIANA: The state uses a modified version of the Model Penal Code rule. The burden of proof is on the defendant.

IOWA: The state uses the M'Naghten Rule. The burden of proof is on the defendant.

KANSAS: The state has abolished the insanity defense.

KENTUCKY: The state uses the Model Penal Code rule. The burden of proof is on the defendant.

LOUISIANA: The state uses the M'Naghten Rule. The burden of proof is on the defendant.

MAINE: The state uses a modified version of the Model Penal Code rule. The burden of proof is on the defendant.

MARYLAND: The state uses the Model Penal Code rule. The burden of proof is on the defendant.

MASSACHUSETTS: The state uses the Model Penal Code rule. The burden of proof is on the state.

MICHIGAN: The state uses the Model Penal Code rule. The burden of proof is on the state.

MINNESOTA: The state uses the M'Naghten Rule. The burden of proof is on the defendant.

MISSISSIPPI: The state uses the M'Naghten Rule. The burden of proof is on the state. An acquitted by reason of insanity verdict is allowed.

MISSOURI: The state uses a modified version of the M'Naghten Rule. The burden of proof is on the defendant.

MONTANA: The state has abolished the insanity defense, although a guilty but insane verdict is allowed.

NEBRASKA: The state uses the M'Naghten Rule. The burden of proof is on the defendant.

NEVADA: The state uses the M'Naghten Rule. The burden of proof is on the defendant.

NEW HAMPSHIRE: The state uses the Durham standard. The burden of proof is on the defendant.

NEW JERSEY: The state uses the M'Naghten Rule. The burden of proof is on the state.

NEW MEXICO: The state uses the M'Naghten Rule with the Irresistible Impulse Test. The burden of proof is on the state.

NEW YORK: The state uses the Model Penal Code rule. The burden of proof is on the defendant.

NORTH CAROLINA: The state uses the M'Naghten Rule. The burden of proof is on the defendant.

NORTH DAKOTA: The state uses the Model Penal Code rule. The burden of proof is on the state.

OHIO: The state uses the M'Naghten Rule. The burden of proof is on the defendant.

OKLAHOMA: The state uses the M'Naghten Rule. The burden of proof is on the state.

OREGON: The state uses the Model Penal Code rule. The burden of proof is on the defendant.

PENNSYLVANIA: The state uses the M'Naghten Rule. The burden of proof is on the defendant.

RHODE ISLAND: The state uses the Model Penal Code rule. The burden of proof is on the defendant.

SOUTH CAROLINA: The state uses the M'Naghten Rule. The burden of proof is on the defendant.

SOUTH DAKOTA: The state uses the M'Naghten Rule. The burden of proof is on the defendant.

TENNESSEE: The state uses the Model Penal Code rule. The burden of proof is on the state.

TEXAS: The state uses the M'Naghten Rule with the Irresistible Impulse Test. The burden of proof is on the defendant.

UTAH: The state has abolished the insanity defense, but guilty but mentally ill verdicts are allowed.

VERMONT: The state uses the Model Penal Code rule. The burden of proof is on the defendant.

VIRGINIA: The state uses the M'Naghten Rule with the Irresistible Impulse Test. The burden of proof is on the defendant.

WASHINGTON: The state uses the M'Naghten Rule. The burden of proof is on the defendant.

WEST VIRGINIA: The state uses the Model Penal Code rule. The burden of proof is on the state.

WISCONSIN: The state uses the Model Penal Code rule. The burden of proof is on the defendant.

WYOMING: The state uses the Model Penal Code rule. The burden of proof is on the defendant.

Additional Resources

American Jurisprudence. 2d Edition. Thomson/West 2005.

Mental Health and Disability Law in a Nutshell. Donald H.J. Hermann, West Group, 1997.

Toward a New Test for the Insanity Defense: Incorporating the Discoveries of Neuroscience into Moral and Legal Theories. Reider, Laura, UCLA Law Review, Oct. 1998.

Organizations

American Bar Association Criminal Justice Section

740 15th Street, NW, 10th Floor
Washington, DC 20005-1009 USA
Phone: (202) 662-1500
Fax: (202) 662-1501
URL: http://www.abanet.org/crimjust/contact.html

American Psychological Association (APA)

750 First Street, NE
Washington, DC 20002-4242 USA
Phone: (202) 336-5510
URL: http://www.apa.org/

Association of Federal Defense Attorneys

8530 Wilshire Blvd., Suite 404
Beverly Hills, CA 90211 USA
Phone: (310) 397-1001
URL: http://www.afda.org



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