Mental illness is all we seem to hear about lately in relation to crime. According to a Bureau of Justice statistical analysis roughly 61% of inmates have a recent history or are currently showing symptoms of mental illness. With those kind of numbers, it is reasonable to think that not guilty by reason of insanity (NGI or NGRI) is a common defense tactic. However, NGI, according to a 1991 study by the National Institute of Health, is used in approximately 1% of criminal cases. Out of the 1% of cases where the NGI defense is used, it is effective approximately 25% of the time. It seems a bit odd that with so much mental illness seen in the criminal justice system that this defense is not used more often or, when it is used, it’s not more …show more content…
The standards for NGI, which vary from state to state, include the M’Naghten Rule, the Irresistible-Impulse Test and the Model Penal Code, while the burden of proof, be it on the state or the defense, also varies. In some states, such as Idaho, Utah, and Montana, the defense has been abolished altogether and others states have added the delineation guilty but insane, or guilty but mentally ill. The M’Naghten Rule states a criminal defendant is not guilty by reason of insanity if, at the time of the alleged criminal act, the defendant was so deranged that he/she did not know the nature or quality of his/her actions or, if he/she knew the nature and quality of his/her actions, he/she was so deranged that he/she did not know that what he/she was doing was wrong. The Irresistible-Impulse Test specifies that a defendant is not guilty if he/she knows that an act is wrong and is aware of the nature and quality of the act, but cannot refrain from committing the act. The Model Penal Code specifies that a defendant is not criminally responsible if the defendant’s conduct is due to either mental disease or defect, and if the defendant lacked substantial capacity to understand criminality or comply with legal