Last updated 14 January 2019
The prosecution must prove on evidence that a person committed an offence. A person may defend a criminal charge by relying on a defence (or combination thereof). A defence (if successful) may either:
- reduce the offence charged to a lesser offence
- provide a complete defence to the charge, which results in the person being acquitted of the offence.
Provocation (ss 268–269 Criminal Code Act 1899 (Qld) (Criminal Code)) is any wrongful act or insult of such a nature as to be likely to deprive an ordinary person of the power of self-control and to induce them to assault that person. The response must be sudden (i.e. done in the heat of the moment) and proportional to the provocation.
Provocation may be raised where the provocative act was directed at a person other than the defendant (e.g. a child or other family member).
Provocation is a complete defence to the following charges:
- common assault
- assault occasioning bodily harm
- unlawful wounding
- grievous bodily harm.
Provocation provides a partial defence to murder. This means that in certain circumstances, the charge is reduced from murder to manslaughter if it occurred ‘in the heat of passion caused by sudden provocation and before there is time for the person’s passion to cool’.
One effect of this reduction is that a person convicted of manslaughter can receive any sentence determined by the judge whereas a person convicted of murder must receive a mandatory sentence of life imprisonment.
Killing for preservation in an abusive domestic relationship
There is a specific partial defence to murder where the accused is a victim of domestic violence. The defence acts to reduce murder to manslaughter if:
- the deceased has committed domestic violence during the relationship
- the accused believed their actions were necessary for their preservation from death or grievous bodily harm and
- this belief is reasonable.
Self-defence to unprovoked assault
Section 271 of the Criminal Code makes it legal for a person to use such force as is reasonably necessary to defend them against an unprovoked assault. The force used must not be intended or likely to cause death or grievous bodily harm, and must be proportionate.
If the person being assaulted reasonably fears that their attacker may cause death or grievous bodily harm, that person can use necessary force to defend themselves (or the person being attacked) even if the force causes the death of, or grievous bodily harm to, the attacker.
Self-defence to provoked assault
If a person assaults someone or provokes an assault, s 272 of the Criminal Code makes it legal for that person to then use reasonable force (even if it results in death or grievous bodily harm) to protect themselves if the other person responded with such violence that the person who provoked the assault reasonably fears they may suffer death or grievous bodily harm.
The defence is not available when the person:
- who first assaults or provokes an assault does so with intent to kill or do grievous bodily harm
- uses the force which causes death or grievous bodily harm before the necessity to do so arose.
The person who uses the force must attempt to remove themselves from the conflict or retreat as far as practicable.
Acting in aid of others
In any circumstances to which self-defence may apply, it may also be lawful for a person acting in good faith to use a similar degree of force for the purpose of defending another person (s 273 Criminal Code).
Defence of moveable property
Sections 274 and 275 of the Criminal Code allow a person to use reasonably necessary force to defend the possession of moveable property, provided that the person does not do grievous bodily harm to the other person.
Defence of premises against trespassers
Sections 277 and 278 of the Criminal Code allow a person in possession of any land structure, vessel or place or who is entitled to control or management of the place to use such force as is reasonably necessary to prevent trespassers, or to remove disorderly persons, so long as the force used does not amount to grievous bodily harm.
Section 267 of the Criminal Code also provides that a person in possession of a dwelling is entitled to use force to prevent or repel another person from unlawfully entering or remaining in the dwelling, if that person believes that force is necessary and the person entering intends to commit an indictable offence in the dwelling.
Honest claim of right
Ignorance of the law is not a defence. For property offences, however, it is a defence to show that the person broke the law by acting in the exercise of an honest claim of right and without any intention to defraud (s 22 Criminal Code).
For example, a person charged with stealing as a result of writing company cheques payable to themselves, cashing those cheques and keeping the money may say they have a claim of right if:
- as an employee of the company, they were authorised to write company cheques
- the money was taken as a result of underpayment of wages owed by the company to them
- they took the money honestly believing it was for wage payments.
If the claim of right defence is successful, the person would be not guilty of stealing. The claim of right must be honest although not necessarily a reasonable one.
Unwilled and accidental acts
A person is not criminally responsible for an act or omission that occurs independently of the exercise of the person’s will or that occurs by accident. However, (s 23(1A) Criminal Code) provides that a person is not excused from criminal responsibility for death or grievous bodily harm that results to a victim because of a physical defect, weakness or abnormality, even though the offender does not intend or reasonably foresee the death or grievous bodily harm.
Mistake of fact
A person is not criminally responsible if they did something based upon an honest and reasonable mistake of fact (s 24 Criminal Code). For instance, a person charged with rape may raise as their defence the fact that they had an honest but mistaken belief that the victim consented to sexual intercourse.
Sudden or extraordinary emergency
A person is not criminally responsible for an act or omission done under a sudden or extraordinary emergency that an ordinary person, possessing ordinary powers of self-control, could not reasonably be expected to act otherwise (s 25 Criminal Code).
Every person is presumed to be sane until the contrary is proven. This means that a defendant must show on the balance of probabilities that they were of unsound mind at the time of the offence.
A person is insane and not criminally responsible if they are deprived of one or more of the following capacities:
- understand what they are doing
- control their actions
- know that they ought not to be doing it.
In Queensland, the Mental Health Court generally determines whether a person was of unsound mind at the time of the offence or if they are fit for trial. The prosecution is discontinued if the Mental Health Court makes a finding of unsoundness of mind or permanent unfitness (ss 26 and 27 Criminal Code).
A defendant may rely on alibi evidence to show that they were not at the relevant location at the time of the offence. Alibi evidence can be given by the accused and by other witnesses.
Section 590A of the Criminal Code states that on an indictable offence a defendant must lodge a Notice of Alibi with the Director of Public Prosecutions within 14 days of the date the person is committed for trial. This enables the prosecution to investigate the alibi before trial.
This defence applies when the accused acted without conscious volition due to some external cause at the time of committing the offence (s 23 Criminal Code). Examples can include an epileptic fit, concussion or sleep walking.
Voluntary intoxication is not a defence and nor can it be taken into account as a mitigating feature on sentence. The insanity defence provisions similarly apply to a person whose mind is disordered by involuntary intoxication or stupefaction.
Section 28(3) (Criminal Code) provides that intentional intoxication should be considered in determining whether intention exists in relation to offences that require an intention to cause a specific result. Murder is the most important of the few offences that contain an element of intention.
Diminished responsibility is a partial defence in that it reduces murder to manslaughter if at the time of the act or omission which caused death, the person is in such a state of abnormality of mind as to substantially impair their capacity to understand what they are doing, to control their actions and/or to know that they ought not to be doing it (s 304 Criminal Code).