The court seeks to clarify and reevaluate the standard for the insanity defense and undertakes both a historical and modern evaluation of current and past approaches to the defense.
“Whether the court should abandon the M’Naghten test in favor of a new standard for determining the criminal responsibility of those who claim they are blameless by reason of mental illness.”
Yes. Before one can be culpable, the law requires a showing of mens rea. None of the three purposes of criminal law are satisfied – rehabilitation, deterrence, and retribution – when the insane are punished.” The current problem is distinguishing between cases where a correctional and punitive purpose exists and cases where a medical-custodial outcome is legally desired. The M’Naghten test emphasizes knowledge of right or wrong as the sole symptom of insanity. This standard “refuses to recognize volitional or emotional impairments, viewing the cognitive element as the singular cause of conduct.” The M’Naghten test focuses on an all or nothing approach and does not appreciate that all modes of personality and behavior and affected by insanity, such as individual will and emotions. The “irresistible impulse” test inquires “into both the cognitive and the volitional components of the defendant’s behavior.” This test focuses on complete domination of the affected’s mind. This test requires that the defendant act in an “explosive fit” and does not realistically include the insane who brood over an act or behave in a melancholy fashion. The “product test” declared that the insane are not guilty “if his unlawful act was the product of mental disease or mental defect.” This test was deficient because, although it allowed for a wide range of expert testimony, it left the door open as to causation, in that there was no real standard for what caused the behavior.
The model penal code rule “acknowledges that volitional as well as cognitive impairments must be considered by the jury in its resolution of the responsibility issue and … employs vocabulary sufficiently in the common ken that its use at trial will permit a reasonable” conversation between judges, jury, and lawyers. The test is that “A person is not responsible for criminal conduct if at the time of such conduct, as a result of the mental disease or defect, his capacity either to appreciate the wrongfulness of his conduct or to conform his conduct to the requirements of law is so substantially impaired that he cannot justly be held responsible.” This test puts the issue of criminal liability on the jury and asks them to evaluate blameworthiness of the defendant by considering what he should be legally and morally responsible for in light of community standards, etc. The test does not include “psychopathic or sociopathic personality disorders in the definition of mental illness. This test also allows psychiatrists to testify to a jury in such a way that they can understand all factors of the illness.
“The charge to the jury must include unambiguous instructions stressing that regardless of the nature and extent of the experts’ testimony, the issue of exculpation remains at all times a legal and not a medical question… First, it must measure the extent to which the defendant’s mental and emotional processes were impaired at the time of the unlawful conduct… Second, the jury must assess that impairment in light of community standards of blameworthiness.”