Insanity
Insanity, also known as insane automatism, is covered by the M’Naghten Rules. Although they deal with what they describe as insanity, it is insanity in the legal sense and not in the medical or psychological sense. The Rules are contained in replies given by the judges of 1843 to certain abstract questions which were placed before them in M’Naghten’s Case.
The basic propositions of the law are to be found in the answers to Questions 2 and 3. The Rules lead to a special verdict of “not guilty by reason of insanity” and leave the defendant under the control of the court.
Disease of the Mind
Whether a particular condition amounts to a disease of the mind within the Rules is not a medical but a legal question to be decided in accordance with the ordinary rules of interpretation. It seems that any disease, which produces a malfunctioning of the mind, is a disease of the mind, and need not be a disease of the brain. It covers any internal disorder, which results in violence and is likely to recur. The following conditions have been held to amount to a disease of the mind:
- Arterial-sclerosis, a condition which restricts the flow of blood to the brain and can cause a temporary lapse of consciousness (R v Kemp);
- Psychomotor epilepsy, a disease of the nervous system, which may cause a mental blackout (Bratty v A-G for N. Ireland);
- Epilepsy (R v Sullivan);
- Hyper-glycaemia, high blood sugar level caused by diabetes (R v Hennessy); and
- Sleep-walking which had previously been thought to be an example of automatism rather than insanity, but it is now clear that the courts will treat sleep-walking as an example of disease of the mind with internal causes unless there is clear evidence of an external causal factor (R v Burgess).
Defect of Reason
The disease of the mind must have given rise to a defect of reason which had one of two consequences: either (a) the defendant did not know the nature and quality of his act, or (b) he did not know his act was wrong. The phrase “defect of reason” seems to mean that the powers of reasoning must be impaired, not merely confusion or absentmindedness. See: R v Clarke.
Nature and Quality of the Act
This phrase refers to the physical nature and quality of the act.
It covers the situation where the defendant does not know what he is
physically doing. For example, in Kemp the defendant
was unaware of his actions because of a “blackout”.
Knowledge that the Act was Wrong
If the defendant knew what he was doing then he will still be insane
if he did not know that he was doing something legally wrong.
See:
R v Windle and
Johnson.
Insane Delusions
The judges were asked in M’Naghten’s Case if a person could be excused if he committed an offence in consequence of an insane delusion. They replied that if he labours under such partial delusion only, and is not in other respects insane, “he must be considered in the same situation as to responsibility as if the facts with respect to which the delusion exists were real”. Therefore, delusions which do not prevent the defendant from having mens rea will not lead to a defence.
Effect of Insanity
The Rules lead to a special verdict of “not guilty by reason of insanity” and leave the defendant under the control of the court. The sentencing powers of the court are in s3 of the Criminal Procedure (Insanity and Unfitness to Plead) Act 1991:
- Where the sentence for the offence to which the finding relates is fixed by law - in effect, murder - the court must make a hospital order restricting discharge without limitation of time.
- In any other case the court may make a hospital order and an order restricting discharge either for a limited or unlimited period of time; or
- In appropriate circumstances: a guardianship order; a supervision and treatment order; or an order for absolute discharge.
Note: A hospital order is an order that the defendant be admitted to and detained in a hospital in order to receive treatment for a mental disorder. Such an order may be made upon proper medical evidence and only after a conviction for an imprisonable offence. (See ss37-43 Mental Health Act 1983.)
You may be interested in looking at the CPS guidelines on mentally disordered offenders.