The problem of alcohol- and drug-fuelled violence has been in the news recently. These stories place the spotlight squarely on the issue of intoxication and crime. Some allowance is made in Australian criminal law for the effect of intoxication on a person accused of committing a crime. While not a defence in itself, intoxication may indirectly help a defence by providing the basis for a reasonable doubt that an accused person had the necessary mental element (eg intention) to commit the crime of which they are charged. However – and possibly indicative of underlying community values and attitudes – its availability is limited, and it is even open to the prosecution to use intoxication to prove an accused person’s guilt.

In most Australian jurisdictions, an accused is not able to rely on evidence of self-induced intoxication to raise a reasonable doubt that she or he had the necessary intention to commit the physical act of a crime of “basic intent” – such as manslaughter, assault, and unlawfully causing grievous bodily harm. Section 428D of the Crimes Act 1900 (NSW), for example, provides that self-induced intoxication at the relevant time “cannot be taken into account” in determining whether an accused had the requisite mental element “for an offence other than an offence of specific intent”. Intoxication that was not self-induced may be taken into account though.

Again, an accused may be able to rely on evidence of intoxication, even if self-induced, to raise a reasonable doubt with regards to any specific intention to achieve a particular outcome required by a “specific intent” offence. Crimes of so-called specific intent are crimes committed for a particular purpose, eg murder and wounding with intent to cause bodily harm, as opposed to having no particular purpose other than carrying out a certain physical act (“basic intent”).

This arguably contradictory quality of intoxication in the defence context suggests it is not clear-cut whether an accused person should be advised to pursue it as a line of defence. This is especially so when it is considered that the prosecution may use evidence of intoxication to infer the requisite criminal intent on the part of an accused. Being a “known disinhibitor”, intoxication may be used by the prosecution to show that a person deliberately tried to remove her or his capacity for self-control so as to be able to commit a crime.

A further consideration for an accused would be that evidence of self-induced intoxication may result in a greater penalty, though conversely, it may also be used in mitigation if the accused was intoxicated in circumstances beyond her or his control. The NSW Government has announced that it will remove self-induced intoxication as a mitigating factor in the determination of penalties.

Intoxication cannot be used to negate intention where an essential element of an offence, such as driving under the influence of alcohol, is the impairment caused by intoxication. To have intoxication available as a defence in this context would be to defeat the purpose of the applicable law. Intoxication in relation to criminal responsibility is explored in updated Chapter 10 of The Laws of Australia Subtitle 9.3 “Defences and Responsibility”. The Subtitle also examines a range of other available criminal defences and principles of criminal responsibility.