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Attacks on the insanity defense


The insanity defense refers to that branch of the concept of insanity which defines the extent to which men accused of crimes may be relieved of criminal

responsibility by virtue of mental disease. The terms of such a defense are to be found in the instructions presented by the trial judge to the jury at the close of a

case. These instructions can be drawn from any of several rules used in the determination of mental illness. The final determination of mental illness rests solely on the

jury who uses information drawn from the testimony of "expert" witnesses, usually professionals in the field of psychology. The net result of such a determination

places an individual accordingly, be it placement in a mental facility, incarceration, or outright release. Due to these aforementioned factors, there are several

problems raised by the existence of the insanity defense. Problems such as the actual possibility of determining mental illness, justifiable placement of judged

"mentally ill" offenders, and the overall usefulness of such a defense. In all, I believe that these problems, as well as others which will be mentioned later, lead us to

the conclusion that the insanity defense is useless and should be abolished entirely.

Insanity is a legal, not a medical definition. Therefore, mental illness and insanity are not synonymous: only some mental illness constitutes insanity. Insanity, however,

includes not only mental illness but also mental deficiencies. Due to this, there are problems in exactly how to apply a medical theory to a legal matter (Herman,

1983;128). The legal concepts of mental illness and insanity raise questions in a conflict between what are termed legalistic criminology and scientific criminology:

mens rea, punishment v. treatment, responsibility, and prisons v. hospitals. This debate seesaws to and fro amidst a grey area between law and science. The major

difficulty with a theory such as mental illness is that it is just that, a theory. To scientists theories are a way of life, but applied to the concept of law theories become

somewhat dangerous. By applying a loose theory such as mental illness to law we are in essence throwing the proverbial "monkey wrench" into the wheels of justice.


At the center of the legal use of insanity lies the mens rea. Every crime involves a physical act, or actus reus, and a mental act, or mens rea, the non-physical cause

of behavior. The mens rea is the mental element required for a crime, and if absent excuses the defendant from criminal responsibility and punishment (Jeffery,

1985;49). The difficulty here lies in analyzing the mens rea. In order to do this lawyers apply one of several rules used by psychologists. These rules range from the

Irresistible Impulse Test to the M'Naghten Rule. Each of these rules approach mental illness/capacity in a different way and in my opinion each falls short of actual

proof. I will discuss each in detail.

The M'Naghten Rule The M'Naghten Rule, also known as the right-wrong test, arose in 1843 during the trial of Daniel M'Naghten who argued that he was not

criminally responsible for his actions because he suffered from delusions at the time of the killing. The M'Naghten Rule reads: A defendant may be excused from

criminal responsibility if at the time of the commission of the act the party accused was laboring under such a defect of reason, from a disease of the mind, as not to

know the nature and the quality of the act he was doing, or if he did know it, that he did not know that he was doing what was wrong. Thus, according to the rule, a

person is basically insane if he or she is unable to distinguish between right and wrong as a result of some mental disability.

Criticism of the M'Naghten Rule has come from both legal and medical professions. Many criticize that the test is unsound in its view of human psychology.

Psychiatry, it is argued, views the human personality as an integrated entity, not divisible into separate compartments of reason, emotion, or volition (Herman,

1983;138). Additionally, the test is criticized for defining responsibility solely in terms of cognition. While cognitive symptoms may reveal disorder, they alone are

not sufficient to give an adequate picture of such a disorder or determine responsibility. Also, it has been shown that individuals deemed insane by psychologists

have possessed the ability to differentiate right from wrong. I believe that the major weakness of this test, however, lies in the fact that courts are unable to make

clear determinations of terms such as disease of the mind, know, and the nature and quality of the act.

The Irresistible Impulse Test This rule excludes from criminal responsibility a person whose mental disease makes it impossible to control personal conduct. Unlike

the M'Naghten Rule, the criminal may be able to distinguish between right and wrong, but may be unable to exercise self-control because of a disabling mental

condition. Normally this test is combined with the M'Naghten Rule. Many of the criticisms of the Irresistible Impulse Test center around the claim that the view of

volition is so extremely narrow that it can be misleading. Just as the M'Naghten Rule focused on cognition rather than the function of the person in an integrated

fashion, the Irresistible Impulse Test abstracts the element of volition in a way that fails to assess a person's function in terms of an integrated personality.

Additionally, it has been asserted that the concept at best has medical significance in only minor crimes resulting from obsession-compulsion, and that seldom, if

ever, can it be shown that this disorder results in the commission of a major crime (Seigel 1993;144). Such a claim is subject to the objection that it cannot be

conclusively proven. Interestingly, it has been shown by many psychiatric authorities that no homicidal or suicidal crime ever results from obsession-compulsion


Another criticism of this test is the difficulty, if not the impossibility, of proving the irresistibility of the impulse, which the definition of the test requires. The jury, as I

said earlier, has the final decision, and is faced with deciding when the impulse was irresistible and when it was merely unresisted, a task that psychiatrists suggest is

impossible to perform. We are also able to argue that the test is one of volition. It is too narrow in that it fails to recognize mental illness characterized by brooding

and reflection (Herman 1983;140). The test is misleading in its suggestion that where a crime is committed as a result of emotional disorder due to insanity, it must

be sudden and impulsive.

The Durham Rule The Durham Rule, also known as the Products Test, is based on the contention that insanity represents many personality factors, all of which may

not be present in every case. It was brought about by Judge David Bazelon in the case of Durham v. U.S. who rejected the M'Naghten Rule and stated that the

accused is not criminally responsible if the unlawful act was the product of mental disease or defect.

The primary problem with this rule of course lies in its meaning. Again it is impossible for us to define mental disease or defect, and product does not give the jury a

reliable standard by which to base a decision. It is unnecessary to offer further criticism, for my purpose I believe this attempt fails at it's onset.

The Substantial Capacity Test Another test is termed the Substantial Capacity Test which focuses on the reason and will of the accused. It states that at the time of

the crime, as a result of some mental disease or defect, the accused lacked the substantial capacity to (a) appreciate the wrongfulness of their conduct or (b)

conform their conduct to the requirements of the law. This test is disputable in the fact that it is not only impossible to prove capacity of reason or will, but to even

test such abstracts seems absurd. Additionally, the term "substantial capacity" lies question in that it is an abstract impossible to define.


The meaning of insanity is the legal definition as put forth in a rule such as the M'naghten Rule or whatever school of thought is in use on any given day. The legal test

is applied in an adversary system which pitches lawyer against psychiatrist and psychiatrist against psychiatrist. Because of this, the psychiatrist is often perceived not

as a scientist but a partisan for the side which is paying for his testimony (Jeffery, 1985;56). The major problem in this case being that the use of a neutral expert is

impossible to implement. In the end the determination of insanity is a layman's decision since it is the jury which ultimately decides whether the defendant is sane or

insane. This of course is ludicrous since professional scientists cannot agree on the meaning of mental illness. How can a layman make such a decision especially

after listening to contradictory testimony which is manipulated by opposing lawyers. I believe that the major problem that we can point out here is in the futility of

asking psychiatrists to testify in terms of legal concepts of insanity. The psychiatrist finds himself in a double bind: he has no medical definition of mental illness and he

must answer questions from lawyers concerning legal insanity, right and wrong, and irresistible impulses. As stated by Packer: "The insanity defense cannot tolerate

psychiatric testimony since the ethical foundations of the criminal law are rooted in beliefs about human rationality, deterribility, and free will. These are articles of

moral faith rather than scientific fact."


In the insanity defense we have no variable independent of the criminal behavior we are studying. Insanity refers to a class of behaviors known by observing the

behavior of the patient, and criminality is a class of behavior likewise known by observing the behavior of the defendant. We are involved in classification and labels.

Where we have one class of behaviors labeled as schizophrenia, and the other class labeled as crimes, what we have are two co-existing classes of behavior in the

same individual, and not a cause or effect relationship (Simon, 1988;47). A person can be Catholic and commit a robbery without a casual relationship existing;

likewise, a person can be schizophrenic and a robber without a casual relationship existing between the two classes of behavior. Coexistence does not show a

casual relationship. Behavior cannot cause behavior.

What we must do, in order to prove a relationship between mental illness and criminal behavior is produce some independent link between the two classes of

behavior on a biochemical level. We must have a definition of mental illness independent of the behavioral symptoms in order to establish a casual relationship

between crime and mental illness. There is such a view and it is termed the Biological Psychiatric view. The view basically states that there is some defect or

malfunction in the actual make-up of the brain of an individual which causes schizophrenia. This same defect then causes the criminal behavior such as robbery or

murder. The problem here is that we have no actual way of mapping the brain and conclusively determining exactly what portion thereof is responsible for either

type of behavior much less that one area is responsible for both. In essence even if true this theory is unprovable.

There is also a statistical relationship between crime and mental illness. Guttmacker and Weihofen found 1.5 percent of the criminal population psychotic, 2.4

percent mentally defective, 6.9 percent neurotic, and 11.2 percent psychopathic (Jeffery, 1985:66). These figures are very unconvincing. Additionally they are

based on old diagnostic categories and procedures which are most unreliable. Also, the meaning of neurotic or psychotic or psychopathic is uncertain within the

context of these studies and they do not refer to modern biological categories of brain disease. Terms such as insanity, mental illness, and mens rea have no scientific

meaning, therefore we must leave as unspecified and uncertain the relationships between insanity, mental illness and criminal law. We certainly cannot conclude that

mental illness bears any relationship to diseases of the brain, nor can we conclude that mental illness or insanity causes criminal behavior.


Not only is there no agreement as to the meaning of insanity and mental illness, but to add further confusion, there is a school of thought that states that mental illness

is a myth and does not exist. This approach is found in the works of such persons as Thomas Szasz (1961;1963) who argues that mental illness is a myth and label

applied to behavior by psychiatrists who are making political and ethical decisions, and Laing (1969;1971) who claims that labels are being used by society to

impose violence and control on people. View such as these and others deny the physical and biological basis of behavioral disorders. They separate completely

biology and behavior, brain and behavior, and mental and physical. The fact that we refer to "mental" disease has been cited as evidence that we do not regard it as

disease but as something outside the realm of biological science. Szasz states, for example, that the psychiatrist confuses physical disease and neurological disorders

with mental diseases.

A study in evidence of this was done by Rosenhan (Ziskin, 1975:54) known as "Being Sane in Insane Places." Rosenhan, a psychologist, placed eight normal

people in mental hospitals as "pseudo-patients." They were diagnosed as schizophrenic, and later on when they appeared normal, rediagnosed as schizophrenia in

remission. After one experiment one hospital challenged Rosenhan to send them "pseudo-patients" during the next several months. At the end of the period the

hospital announced that they had discovered that 12 percent of their admission were "pseudo-patients" from Rosenhan went in fact none had ever been sent.


As we have already seen, there is much confusion dealing with the placement of insanity and mental illness, it's definition, and even it's very existence. We have

likewise seen the use of several of the various testing techniques used to determine mental illness and their shortcomings. This information alone would lead us to

believe that the insanity defense needs at least to be revised and improved in many areas. What we have looked at thus far is what precedes the actual judgment of

sanity. What we have not looked at, however, is that implementation of the actual judgment of sanity. That is to say, the actual results of the defense when

successful. I believe that it is here that we will see the most heinous travesties of justice.

There are several decisions which can be reached when insanity is at last proven. These judgements include not guilty by reason of insanity (NGI), and guilty but

mentally ill (GMI), with the later verdict not being implemented until the early eighties in an attempt to reform the insanity defense and decrease the amount of NGI

verdicts. The NGI verdict is the more dangerous verdict and the one which I believe has the strongest argument against the insanity defense. The objection here is

that it allows dangerous men to return to the streets where they commit heinous crimes. Of the 300 persons committed on NGI verdicts 80 percent were released

from mental hospitals by psychiatrists, and in several instances these mental patients went on to kill again (Jeffery, 1985;73). My belief is that psychiatrists and

mental hospitals do not cure the mentally ill. This is the reality of the insanity defense which I find irrefutable; in many cases criminals are released due to loopholes

such as the insanity defense to simply commit the same crime again. Even is these cases make up 10 out of 100,000, there now exist 10 crimes that need not have


The guilty but mentally ill approach has three serious flaws. First it strikes indirectly at the mens rea requirement, introducing the slippery notion that the accused had

partial, but not complete, criminal intent. Second, it creates a lesser and included offense that judges and juries may choose as simply a compromise verdict. They

believe the accused probably did something wrong and deserves some punishment, but they are unwilling to bring in a verdict of guilty on the top charge. The GMI

verdict would allow them to split the difference. Finally the GMI verdict is fraudulent on the issue of treatment. As proposed, it makes no provision for treatment of

the person who has been declared mentally ill.

The GBI option has already proved to be a bogus reform. A 1981 Illinois law added the GMI as an additional verdict, retaining the traditional insanity defense. In

Cook County, verdicts of not guilty by reason of insanity actually increased from 34 to 103 between 1981 and 1984. At the same time GMI went from 16 in 1982,

the first year the option was available, to 87 in 1984. There has been much evidence of a "hydraulic" effect that was contrary to the law's intent. In both Illinois and

Michigan, GMI verdicts involved people who would otherwise have been found guilty, not defendents who would have been found not guilty by reason of insanity

(Walker, 1994;155-156).

The real function of the GBI option is to appease public opinion. The public has little concern for the details of what actually happens to a mentally ill criminal

defendent. Basically, it wants a symbolic statement of "guilty." In practice, the GMI verdict has as much meaning as "guilty but brown eyes."

How dangerous is the GMI verdict? As we say with the NGI verdict, many extremely dangerous mentally ill criminals were simply released onto the streets where

they committed the same crimes. Does the GMI verdict solve this problem? We have some "natural experiments" on this questio rising from some court decisions. A

1971 decision forced to reassessment of 586 inmates of Pennsylvania's Fairview State Hospital for the Criminaly Insane who were placed there under the GMI

verdict. Over two-thirds were eventually released. Over the next four years, 27 percent were rearrested. Eleven percent were rearrested for violent crime. Including

some others who were rehospitalized for a violent act, a total of 14.5 percent of those released proved to be dangerous.


Abolishing the insanity defense is easier said than done for the simple reason that the mens rea requirement remains a fundamental legal principle. The proposal that

"mental condition shall not be a defense to any charge of criminal conduct" could be interpreted in one of two ways. The broader interpretation would mean that

absolutly no aspect of mental condition could be taken into account. In effect, this interpretation would abolish the mens rea requirement altogether. The prosecution

would not have to prove anything about the accused's mental state. This is unneccessarry. For one thing, it would wipe out the distintions that separarte first-degree

murder, second-degree murder, and manslaughter. It is doubtful that anyone againt the insanity defense would choose to take this approach. So sweeping, in fact,

would be it's effect, that it would probably be declared unconstitutuional.

A more limited reading of the wording "mental condition shall not be a defense to any charge of criminal conduct" would mean that an affermative plea of "not guilty

by reason of insanity" could not be raised. The crucial distinction here is drawn between affermative and ordinary defenses. An ordinary defense is simply an attempt

to shown that the prosecution has failed to connect the accused with the crime, a defense used in everyday law. An affermative defense is raised when the

prosecution has connected the accused with the crime, as in an example of self-defense. The defense argues that, yes, the accused did shoot and kill the person and

did so intentionally, but because the act was commited in self-defense the accused does not bear criminal responsibilty for it. The same is true in the case of a

criminal act commited under duress. The insanity defense, in this respect, is an affermative defense. It is this usage that needs to be abolished. In cases such as self

defense it may be an adequate and totally acceptable defense, for in how many cases do you hear of a man being aquitted due to a self-defense plea returning to the

streets in order to kill again? To draw a comparison between the two and argue that both defenses are neccessarry to the total order is naive and unfounded.


The law of insanity involves the conceptes of mens rea and punishments, as does the criminal law in general. Insanity is a legal concept, not a medical concept, and

insanity is defined within the context of an adversary system wherin psychiatrists and lawyers battle one another over the meaning of terms such as "right and wrong"

and "ability to control one's behavior."

Mental illness and mental disease are psychoanalytic concepts, not scientific concepts. Mental illness is defined by talking to people or by giving them written tests,

and there is no agreement among psychiatrists as to the meaning of this illness or whether or not it really exists. Some psychiatrists call mental illness a myth. The

psychoanalyst has not been successful in treating or predicting mental illness.

The psychoanalyst has never established a casual relationship between mental illness and criminal behavior. The insanity defense would require both a mental illness

and a relationship between the illness and the criminal behavior, neither of which could be scientificly established.

Of the criminals both aquited and convicted using the insanity defense, a good number have shown conclusive evidence of recidivism. Many dangerous persons are

allowed to return to the streets and many non-dangerous persons are forced into facilities due to an insanity plea adding further confusion and injustice within both

the legal and medical systems.

In my opinion the iunsanity defense is impossible to maintain on the basis of rules such as the M'Naghten Rule, and the relationship between law and psychiatry must

be reestablished on a more scientific level, based on the neurological work now going on in the brain sciences. The insanity defense is impracticle in it's present

usage and should therefore be abolished.

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