-Can be used for all offences. Results in a special verdict (not guilty by reason of insanity) BUT common sentencing options under the Criminal Procedure (Insanity) Act 1991 are: Hospital order (always in murder cases), Supervision/treatment order etc. Sometimes an absolute discharge.
M'Naghten- M'Naghten rules, courts begin by presuming that everyone is sane. D must deny he is insane on a balance of probabilities. Must be shown that he was suffering from:
- Defect of Reason coming from a
- Disease of the Mind, so that D EITHER
- Does not know the nature and quality of his act OR -Does not know what he is doing is wrong
Defect of Reason
Clarke- Totally deprived of the power of reasoning. Not those who are just absentminded/confused.
Doesn't matter if D's impairment was permanent/temporary. (If D is suffering from epilepsy, the defect of reason will be during this fit).
Disease of the mind
-Legal (rather than medical) definition, meaning a malfunctioning of the mind. Eg, Arteriosclerosis, sleepwalking, epilepsy, diabetic states and psychiatric disorders (ie schizophrenia).
INTERNAL CAUSE = INSANITY
Kemp- D suffering from Arteriosclerosis, can be mental or physical illness. Must affect D's faculties of reason, memory or understanding.
Sullivan- Epileptic fit.
Burgess- Sleepwalking (Internal factor).
Henessy- HypERglycaemia (internal)- failed to take insulin.
Quick- HypOglycaemia (external)- failed to eat after taking insulin.
Did not know the nature and quality of act
1. Unconscious or impaired consciousness so is not aware of what he is doing OR 2. Conscious, but due to condition does not understand or know what he is doing.
Codere- Conscious, but did not know what he was doing.
Did not know what he was doing was (legally) wrong
Johnson- Knew what he was doing but thought he was morally justified. (Insanity not allowed).
Townley- Knew what he was doing/that it was wrong. (Insanity not allowed).