Review of the Crimes (Mental Impairment and Unfitness to be Tried) Act 1997: Report

Appendix E: Jurisdictional comparison of the mental impairment defence

Jurisdiction

Legislation

Definition

Victoria

Crimes (Mental Impairment and Unfitness to be Tried) Act 1997 (Vic)

s 20(1)—The defence of mental impairment is established for a person charged with an offence if, at the time of engaging in conduct constituting the offence, the person was suffering from a mental impairment that had the effect that—

(a) he or she did not know the nature and quality of the conduct; or

(b) he or she did not know that the conduct was wrong (that is, he or she could not reason with a moderate degree of sense and composure about whether the conduct, as perceived by reasonable people, was wrong).

The term ‘mental impairment’ has the common law meaning of ‘disease of the mind’.

Commonwealth

Criminal Code Act 1995 (Cth)

s 7.3(1)—A person is not criminally responsible for an offence if, at the time of carrying out the conduct constituting the offence, the person was suffering from a mental impairment that had the effect that:

a) the person did not know the nature and quality of the conduct; or

b) the person did not know that the conduct was wrong (that is, the person could not reason with a moderate degree of sense and composure about whether the conduct, as perceived by reasonable people, was wrong); or

c) the person was unable to control the conduct.

s 7.3(8)—Mental impairment includes senility, intellectual disability, mental illness, brain damage and severe personality disorder.

s 7.3(9)—Mental illness is a reference to an underlying pathological infirmity of the mind, whether of long or short duration and whether permanent or temporary, but does not include a condition that results from the reaction of a healthy mind to extraordinary external stimuli. However, such a condition may be evidence of a mental illness if it involves some abnormality and is prone to recur.

New South Wales

Mental Health (Forensic Provisions) Act 1990 (NSW)

‘mentally ill’

s 38(1)—If, in an indictment or information, an act or omission is charged against a person as an offence and it is given in evidence on the trial of the person for the offence that the person was mentally ill, so as not to be responsible, according to law, for his or her action at the time when the act was done or omission made, then, if it appears to the jury before which the person is tried that the person did the act or made the omission charged, but was mentally ill at the time when the person did or made the same, the jury must return a special verdict that the accused person is not guilty by reason of mental illness.

Queensland

Criminal Code Act 1899 (Qld)

‘mental disease’ or ‘natural mental infirmity’

s 27(1)—A person is not criminally responsible for an act or omission if at the time of doing the act or making the omission the person is in such a state of mental disease or natural mental infirmity as to deprive the person of capacity to understand what the person is doing, or of capacity to control the person’s actions, or of capacity to know that the person ought not to do the act or make the omission.

s 27(2)—A person whose mind, at the time of the person’s doing or omitting to do an act, is affected by delusions on some specific matter or matters, but who is not otherwise entitled to the benefit of subsection (1), is criminally responsible for the act or omission to the same extent as if the real state of things had been such as the person was induced by the delusions to believe to exist.

Tasmania

Criminal Code Act 1924 (Tas)

‘mental disease’ includes ‘natural imbecility’

s 16(1)—A person is not criminally responsible for an act done or an omission made by him—

(a) when afflicted with mental disease to such an extent as to render him incapable of—

(i) understanding the physical character of such act or omission, or;

(ii) knowing that such act or omission was one which he ought not to do or make, or:

(b) when such act or omission was done or made under an impulse which, by reason of mental disease, he was in substance deprived of any power to resist.

s 16(2)—The fact that a person was, at the time at which he is alleged to have done an act or made an omission, incapable of controlling his conduct generally, is relevant to the question whether he did such act or made such omission under an impulse which by reason of mental disease he was in substance deprived of any power to resist.

s 16(3)—A person whose mind at the time of his doing an act or making an omission is affected by a delusion on some specific matter, but who is not otherwise exempted from criminal responsibility under the foregoing provisions of this section, is criminally responsible for the act or omission to the same extent as if the fact which he was induced by such delusion to believe to exist really existed.

South Australia

Criminal Law Consolidation Act 1935 (SA)

‘mental impairment’

s 269A—Mental illness means a pathological infirmity of the mind (including a temporary one of short duration) and includes a mental illness, an intellectual disability or a disability or impairment of the mind resulting from senility but does not include intoxication.

s 269C—A person is mentally incompetent to commit an offence if, at the time of the conduct alleged to give rise to the offence, the person is suffering from a mental impairment and, in consequence of the mental impairment

(a) does not know the nature and quality of the conduct; or

(b) does not know that the conduct is wrong; or

(c) is unable to control the conduct.

Western Australia

Criminal Code Act Compilation Act 1913 (WA)

‘mental impairment’

s 1(1)—The term mental impairment means intellectual disability, mental illness, brain damage or senility.

s 27(1)—A person is not criminally responsible for an act or omission on account of unsoundness of mind if at the time of doing the act or making the omission he is in such a state of mental impairment as to deprive him of capacity to understand what he is doing, or of capacity to control his actions, or of capacity to know that he ought not to do the act or make the omission.

s 27(2)—A person whose mind, at the time of his doing or omitting to do an act, is affected by delusions on some specific matter or matters, but who is not otherwise entitled to the benefit of subsection (1), is criminally responsible for the act or omission to the same extent as if the real state of things had been such as he was induced by the delusions to believe to exist.

Australian Capital Territory

Criminal Code 2002 (ACT)

s 27(1)—Mental impairment includes senility, intellectual disability, mental illness, brain damage and severe personality disorder.

s 27(2)—Mental illness is an underlying pathological infirmity of the mind, whether of long or short duration and whether permanent or temporary, but does not include a condition (a reactive condition) resulting from the reaction of a healthy mind to extraordinary external stimuli.

s 28(1)—A person is not criminally responsible for an offence if, when carrying out the conduct required for the offence, the person was suffering from a mental impairment that had the effect that—

(a) the person did not know the nature and quality of the conduct; or

(b) the person did not know that the conduct was wrong; or

(c) the person could not control the conduct.

s 28(2)—A person does not know that conduct is wrong if the person cannot reason with a moderate degree of sense and composure about whether the conduct, as seen by a reasonable person, is wrong.

Northern Territory

Criminal Code Act (NT)

s 43A—’Mental illness’ means an underlying pathological infirmity of the mind, whether of long or short duration and whether permanent or temporary, but does not include a condition that results from the reaction of a healthy mind to extraordinary stimuli (although such a condition may be evidence of a mental illness if it involves some abnormality and is prone to recur).

‘Mental impairment’ includes senility, intellectual disability, mental illness, brain damage and involuntary intoxication.

s 43C(1)—The defence of mental impairment is established if the court finds that a person charged with an offence was, at the time of carrying out the conduct constituting the offence, suffering from a mental impairment and as a consequence of that impairment:

(a) he or she did not know the nature and quality of the conduct;

(b) he or she did not know that the conduct was wrong (that is he or she could not reason with a moderate degree of sense and composure about whether the conduct, as perceived by reasonable people, was wrong); or

(c) he or she was not able to control his or her actions.

New Zealand

Crimes Act 1961 (NZ)

‘natural imbecility’ or ‘disease of the mind’

s 23(2)—No person shall be convicted of an offence by reason of an act done or omitted by him when labouring 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.

Scotland

Criminal Procedure (Scotland) Act 1995 (Scot) c 46

‘mental disorder’

s 51A(1)—A person is not criminally responsible for conduct constituting an offence, and is to be acquitted of the offence, if the person was at the time of the conduct unable by reason of mental disorder to appreciate the nature or wrongfulness of the conduct.

s 51A(2)—A person does not lack criminal responsibility for such conduct if the mental disorder in question consists only of a personality disorder which is characterised solely or principally by abnormally aggressive or seriously irresponsible conduct.

United Kingdom

Mental Health Act 2007 (UK) c 12

‘mental disorder’ means any disorder or disability of the mind

Section 1(2) of the Mental Health Act 2007 (UK)amended section 1(2) Mental Health Act 1983 (UK) and defines mental disorder as ‘any disorder or disability of the mind’.

The former categories of mental disorder (mental illness, mental impairment, severe mental impairment and psychopathic disorder) were abolished and the single definition applies throughout the Mental Health Act 1983.

Canada

Criminal Code, RSC 1985, c C-46, pt 1

s 2—’mental disorder’ means a disease of the mind

s 16(1)—No person is criminally responsible for an act committed or an omission made while suffering from a mental disorder that rendered the person incapable of appreciating the nature and quality of the act or omission or of knowing that it was wrong.