Question

1. Describe the elements of the M’Naughten insanity test and compare it to the elements of the Substantial Capacity Test under the MPC and what tests were combined to form the Substantial Capacity test.

Answer 1

Elements of M’Naughten insanity test :-

1. The defendant must be suffering from a mental defect at the time he or she commits the criminal act. The mental defect can be called a “defect of reason” or a “disease of the mind,” depending on the jurisdiction (Iowa Code, 2010).
2. The trier of fact must find that because of the mental defect, the defendant did not know either the nature and quality of the criminal act or that the act was wrong.

Elements of Substantial Capacity Test :-

1. First element requires the defendant to have a mental disease or defect, like the M’Naghten and irresistible impulse insanity defenses.
2. Second element combines the cognitive standard with volitional, like the irresistible impulse insanity defense supplementing the M’Naghten insanity defense.

Comparison of element of M’Naughten insanity test to Substantial Capacity Test :-

• It is easier to establish insanity under the substantial capacity test because both the cognitive and volitional requirements are scaled down to more flexible standards as compared M’Naughten insanity.
• Unlike the M’Naghten insanity defense, the substantial capacity test relaxes the requirement for complete inability to understand or know the difference between right and wrong.

A Substantial Capacity test established by the Model Penal Code for the insanity defense, including elements of the McNaughten rules and the test of irresistible impulse by allowing the court to consider both awareness of wrongdoing and involuntary compulsion.