In NSW, a person who is charged with a criminal offence has a lawful excuse if they can show they acted in self-defence.
Under section 418 of the Crimes Act, a person is not criminally responsible for an offence if they carried out the conduct constituting the offence in self-defence.
When Is Self-Defence Available?
A person carries out conduct in self-defence if the person believes their conduct is necessary:
- to defend himself or herself or another person, or
- to prevent the unlawful deprivation of liberty, or
- to protect property, or
- to prevent criminal trespass to any land or premises
Further, the conduct must be a reasonable response in the circumstances as he or she perceives them.
The right to act in self-defence therefore arises where two circumstances exist:
- the person must believe his or her conduct was necessary in order to defend himself or herself; and
- the person’s conduct must have been a reasonable response in the circumstances as he or she perceived them.
How Do You Establish Self-Defence?
An accused person must raise the issue of self-defence during their trial for it to be considered by the Court. Once self-defence is raised, the onus is on the prosecution to prove, beyond reasonable doubt, that the person did not carry out the conduct in self-defence.
There are two questions that a Court must answer if self-defence is raised:
- is there is a reasonable possibility that the accused believed that his or her conduct was necessary to defend himself or herself; and
- is there also a reasonable possibility that what the accused did was a reasonable response to the circumstances as he or she perceived them.
If the answer to both questions is ‘Yes’, then the accused person must be found not guilty.
The prosecution must eliminate it as an issue by proving beyond reasonable doubt that the accused’s act was not done in self-defence. The prosecution may do this by proving beyond reasonable doubt that, either:
- the person did not (at the time of the act) believe that it was necessary to do what they did to defend him or herself; or
- the person’s act was not a reasonable response in the circumstances as they perceived them.
In determining the issue of whether the accused person personally believed that their conduct was necessary for self-defence, the Court must consider the circumstances as the accused person perceived them to be at the time. It is the accused person’s perception which must be considered, not what someone else might have perceived.
Is Self-Defence Available for Murder?
Yes. Self-defence is available to defend a murder charge. If the prosecution is not able to prove beyond reasonable doubt that the accused did not believe it was necessary to act in the way they did to defend themself, then the appropriate verdict is “not guilty of murder.” It would then be necessary to consider whether the person is guilty of the lesser charge of manslaughter.
If the prosecution can prove beyond reasonable doubt that the conduct of the accused was not a reasonable response in the circumstances as the accused perceived them because their use of force was unreasonable or excessive, then the verdict would be not guilty of murder but guilty of manslaughter.
