History of Standards for the Insanity Defense

"Absolute Madness"

recognized in English common law in 1600's

"Wild Beast Rule."

(1723) Not guilty by reason of insanity if "totally deprived of reason so as to be as an infant [or a] wild beast."

R v Hadfield (1800)

Not guilty by reason of insanity if "mental defect produced act" {anomalous liberal definition of insanity}

R v M'Naghten (1854)

"To establish a defense on grounds of insanity, it must be clearly proven that, at the time of committing the act... the party accused was labouring under such a defect of reason from disease of the mind, as not to know the nature and quality of the act he was doing; or if he did know it ... he did not know he was doing what was wrong."

Irresistible Impulse

Alabama (1896) legislation adopts Irresistible Impulse rule: "mental disease" may "impair volition or self control even when cognition is relatively unimpaired." Result is similar to the "New Hampshire Rule": not guilty by reason of insanity if the act was "offspring or product of mental disease" (cf. R v Hadfield).

US v Durham (1954)

"An accused is not criminally responsible if his unlawful act was the product of a mental disease or defect." (cf. R v Hadfield).

Homicide Act of 1957 (UK) Diminished Responsibility

1) Where a person kills, or is a party to the killing of another, he shall not be convicted of murder if he was suffering from such abnormality of mind (whether arising from a condition of arrested or retarded development of mind or any inherent causes or induced by disease or injury) as substantially impaired his mental responsibility for his acts or omissions in doing or being a party to the killing.

2) On a charge or murder it shall be for the defence to prove that the person charged is by virtue of this section not liable to be convicted of murder.

3) A person who but for this section would be liable, whether as principal or as accessory, to be convicted of murder shall be liable instead to be convicted of manslaughter.

US v Brawner (1972) ALI Rule

1. A person is not responsible for criminal conduct if at the time of such conduct as a result of mental disease or defect he lacks substantial capacity either to appreciate the criminality of his conduct or to conform his conduct to the requirements of law.

2. As used in this Article, the terms 'mental disease or defect' do not include an abnormality manifested only by repeated criminal or otherwise antisocial conduct.

Insanity Defense Reform Act (1984)

To find the defendant not guilty by reason of insanity, the defendant must prove, by clear and convincing evidence, that, at the time of the commission of the acts constituting the offense, the defendant, as a result of a severe mental disease or defect, was unable to appreciate the nature and quality or the wrongfulness of his/her acts. Mental disease or defect does not otherwise constitute a defense.

Guilty But Mentally Ill (c. 1985)

To find the defendant guilty but mentally ill, you must find the defendant had a substantial disorder of thought or mood which afflicted him/her at the time of the offense and which significantly impaired his/her judgment, behavior, capacity to recognize reality, ability to cope with the ordinary demands of life. The effect of the mental illness, though, is such as to fall short of legal insanity.