The Insanity Defense

Legally Insane: The Insanity Defense

The insanity defense is one of the least successful defenses in a criminal defense case. The determination of the suspect’s mental state at the time of the criminal offense, as well as at the time of trial can be a challenging task; the defense actually has the burden of proof in Federal cases, as well as most State charges, in showing the defendant to be insane.

It is important to note that insanity is actually a legal term, not a psychological one. There are times when the suspect may be psychotic but still don’t fit the legal criteria of insane. The legal definInsanity Defense | A legal conceptition of insanity also varies, depending on which jurisdiction the charge originates. Legal tradition in the United States holds that if an individual is not aware of what they are doing or unaware of the meaning of their behavior, they should not be held criminally responsible. Mens rea is vital to charge and convict someone of a crime. According to the opinion in Durham v. United States, determining if someone is guilty and then punishing should only occur if the individual had both free will to commit the offense and had the intent to do harm.

A forensic psychologist will begin a psychological evaluation to determine if the individual is actually mentally ill, or if they’re malingering; malingering is when a defendant pretends to be mentally ill to avoid a guilty verdict or a lengthy prison sentence. Those who are found to be not guilty by reason of insanity (NGRI) tend to be committed into a psychiatric institution

What is the Standard in Showing an Individual to be Legally Insane in the United States?

Roughly half of the United States uses the M’Naghten rule to define insanity. The M’Naghten test can be referred to as a cognitive test of insanity; its purpose is to assess the thought processes and perceptions of the world at the time of the offense.

According to this rule, an individual will be judged insane if:

  1. The defendant at the time of the offense suffered from “a defect of reason, from a disease of the mind.”
  2. Because of this disease of the mind, the defendant did not understand the meaning of his actions, or the “nature and quality of the act he was doing.”
  3. As a result to the above two requirements, the individual did not know what he was doing was illegal or wrong.

Recently, Arizona passed a law amending the requirements of the M’Naghten test; “knowing the nature and quality of the act” was eliminated from the requirements. The United States Supreme Court also approved this law in Clark v. Arizona.

Only one state, New Hampshire, uses the Durham Test; this only requires that the criminal act was a product of mental disease or impairment. Defendants in this state find it much easier to fit into a legally insane defense; it is often interpreted to mean that any mental illness diagnosis counts as a mental impairment.

The ALI Standard, also known as the Brawner Rule, states: “A person is not responsible for criminal conduct if at the time of the action, as a result of mental disease or defect, he/she lacks substantial capacity either to appreciate the criminality of his conduct to the requirements of the law.” This rule makes it clear that any “mental disease or defect” does not include the manifestation of mental illness due to repeated criminal acts throughout their life. Currently, 20 states use the ALI standard.

Legal Terms

Mens rea: Criminal intent. The state of mind indicating culpability, which is required by statute as an element of a crime.

M’Naghten rule: This definition of insanity was a result of a trial that took place in England over 100 years ago; Daniel M’Naghten’s attempted assassination of of Robert Peel, the British Prime Minister, in 1843.