Defences involving state of mind

Question 1

Insanity

Answer 1

Sec.23 Crimes Act 1961
Insanity

(1) Every one shall be presumed to be sane at the time of the doing or omitting any act until the contrary is proved.

(2) No person shall be convicted of a offence by reason of an act or omitted by him when laboring under natural imbecility or disease of the mind to such an extent as to render him incapable-
(a) Of understanding the nature and quality of the act or omission; or
(b) Of knowing that the act or omission was morally wrong, having regard to the commonly accepted standards of right and wrong.

(3) Insanity before or after the time when he did or omitted the act, and insane delusions, though only partial, may be evidence that the offender was, at the time when he did or omitted the act, in such a condition of mind as to render him irresponsible for the act or omission.

Question 2

M’Naghten’s Rules

Answer 2

The M’Naghten’s Rules are frequently used to establish whether or not a defendant is insane. It is based on the person’s ability to think rationally, so that if a person is insane they were acting under such a defect of reason from a disease of the mind that they did not know:

The nature and quality of their actions, or
That what they were doing was wrong.

Question 3

Automatism

Answer 3

Automatism can be best described as a state of total blackout, during which a person is not conscious of their actions and not in control of them.

Question 4

Sane automatism

Answer 4

The result of somnambulism (sleepwalking), a blow to the head or the effects of drugs.

Question 5

Insane automatism

Answer 5

The result of a mental disease.

Question 6

Intoxication

Answer 6

The general rule has been that intoxication may be a defence to the commission of an offence (excludes offences carrying very simple intent ie assault or fighting in a public place):

Where the intoxication causes a disease of the mind so as to bring Sec.23 (Insanity) of the Crimes Act 1961 into effect.

If intent is required as an essential element of the offence and the drunkeness is such that the defence can plead a lack of intent to commit the offence.

Where the intoxication causes a state of automatism (complete acquittal).

Question 7

Ignorance of law

Answer 7

Sec.25 Crimes Act 1961
Ignorance of law

The fact that an offender is ignorant of the law is not an excuse for any offence committed by him.