Question

Is the Insanity Defense necessary? What form should it take and the role of the forensic psychiatrist in establishing whether an accused person can successfully use it.

Answer 1

There are times when the insanity defense, with all the controversy that surrounds it, is in the news. This is one of those times:

It is highly likely that James Holmes, who is facing 142 felony counts in connection with the Aurora, Colorado shootings on July 22, 2012, will raise an insanity defense. First, he’ll have to be found competent to stand trial, which is a separate issue.

What is the Insanity Defense?

• For a person to be convicted of a crime, the prosecution must prove not only that the person engaged in a guilty act (actus reus), but also that he or she had guilty intent (mens rea). If a person does not have criminal intent during an act, no crime occurs: a person who takes someone else’s property, honestly believing it is his own, is not guilty of larceny.
• But what about situations in which the person commits the act, and intended to do so, but was suffering from a mental or physical condition that impairs their ability to appreciate that they are doing something wrong or to control their behavior? That’s where the insanity defense comes in.
• While the insanity defense is a legal doctrine, at its heart it is the expression of a moral principle found in societies across time and multiple cultures: individuals should not be punished for their otherwise criminal acts if they lack certain characteristics that relate to the ability to engage in rational thinking, including an appreciation of the wrongfulness and consequences of their actions, or control their behavior.
• Take, for example, children. A five year old who sets fire to the drapes because the flames are pretty, will not be charged with arson when the house burns down. The same is true for people with severe developmental disabilities. What about people who cause harm to others or commit crimes while sleepwalking? Yes, those cases exist, and the defendants are generally not held criminally responsible.
• The legal requirements for the insanity defense have varied over the centuries and societies in which it has existed. Here in the United States, public outrage in response to successful insanity defenses in high profile cases has often led to changes that limit the availability of the defense and its likelihood of success.
• For example, in the early 1980’s, the standard for the insanity defense in federal criminal cases was the American Law Institute/Model Penal Code standard. It provides for acquittal on the basis of insanity if as the result of a mental disease or defect, the defendant lacked substantial capacity to appreciate the wrongfulness of his actions or lacked substantial capacity to conform his behavior to the requirements of the law. This was considered to be more lenient than the standard that had been used until then.
• But, after John Hinckley was found not guilty by reason of insanity for his failed assassination attempt on President Ronald Reagan, the federal standard was changed to a stricter version that limits the defense to those with severe mental illness and those who are unable to appreciate the wrongfulness of their conduct.
• Thus, the new federal standard eliminated the volitional component and left only the cognitive component. Many states have followed suit and some have eliminated the insanity defense altogether.
• Regardless of the precise legal standard, the insanity defense is rarely raised and even more rarely successful. It is used in only about 1% of cases in the U.S., and is successful less than 25% of the time.
• What Qualifies as a “Mental Disease or Defect” for the Insanity Defense?
• While any mental or medical condition could theoretically serve as a basis for an insanity defense, the law limits the conditions that can be considered for that purpose. These restrictions are aimed at insuring that only those who truly deserve to be relieved of responsibility are eligible for it. To that end, voluntary intoxication is excluded, as are conditions that have antisocial behaviors as their primary characteristic, e.g. kleptomania, pyromania, and pedophilia and appear to have no physiological basis. Some legal standards require that the mental illness serving as the basis for the defense be “severe.”
• Not every condition that qualifies to be the basis for an insanity defense has an equal chance of succeeding in achieving an acquittal. Those that succeed tend to be marked by either severity or evidence that they arise from a physiological, as opposed to a purely psychological, disorder. These are, for example, mental illnesses that severely affect a person’s perception of reality or, in some jurisdictions, ability to control their behavior. They include psychoses, severe depression, mania, or anxiety disorders like posttraumatic stress disorder (PTSD). An argument that an act of violence was the result of a traumaticbrain injury causing irritability and poor impulse control is more likely to be convincing than the assertion that the violence arose from personality disturbance.

How Will Advances in Neuroscience and Genetics Affect the Insanity Defense?

• The presence of abnormal brain function due to injury, tumor, and epilepsy has been successfully offered as the basis for an insanity defense in number criminal cases hundreds of years.
• When it has been successful, the apparent key to the success of these defenses lies in the concrete and observable nature of the abnormality: juries can see the tumor on a brain scan, and may be presented with evidence that the criminal behavior did not occur before the injury or that it stops after treatment.