Criminal Defence WA

This page contains a brief summary of some of the defences to criminal charges in Western Australia. Where a defence is raised by the evidence at a trial, the prosecution is required to disprove the defence beyond reasonable doubt. The contents of this page is not intended to be taken as legal advice. If you have been charged with a criminal offence, we urge you to contact our office and make an appointment with one of our solicitors to obtain advice about whether a defence may be available in the circumstances of your case.


(i)                 Complete defence to offences involving violence

(ii)              Subjective and objective elements

Objective: reasonable grounds for belief act was necessary

Subjective: actually believed act and degree of force was necessary, personal experience, characteristics relevant

(iii)            Subject to proportionality test:

-          Regard to gender, size, fitness etc

-          Use of weapon – was complainant armed?

-          Degree of force – more than reasonably necessary?

-          Death or grievous bodily harm require belief assault upon person will cause death or GBH.  


(i)     Available where an assault is an element of charge

(ii)  Wrongful act or insult (cannot be lawful act)

(iii)  Objective test – would an ordinary person, subjected to the provocation, have lost their power of self-control?

(iv)  Subject to proportionality test 

Defence of Property

(i)                 Force used must be reasonable and proportionate.

(ii)              Must have held subjective belief that the use of force was reasonably necessary

(iii)            Must be objectively reasonable grounds for that belief.


Defence of Home

(i)                 Force used must be reasonable and proportionate.

(ii)              Must have held subjective belief that the use of force was reasonably necessary

(iii)            Must be objectively reasonable grounds for that belief.


Honest and Reasonable Mistake of Fact

(i)                 Belief about state of things, which if existed, consistent with innocence of offence

(ii)              Includes compound/mixed mistake of fact and law (eg. Status of licence, marriage)

(iii)            Does not apply to pure errors of law.

(iv)             Question of whether a thing properly characterised answers a statutory description is a question of law.

(v)               Must have objective grounds for belief for it to be reasonable.

(vi)             Honest – subjective test

(vii)          Must be a positive belief

(viii)        Available in relation to element of consent – sexual offences.  


(i)                 Is not available as a defence where intoxication was self-induced, except where an  intention to create a specific result is an element of the offence.

(ii)              Where intention is an element of the offence, intoxication is relevant to the issue of whether an accused had formed the intention to create a particular result. 

(iii)            Also available where intoxication was unintended, for example where a person unwittingly ingests an intoxicating substance.  

Honest Claim of Right – Property Offences

(i)                 Honest belief of lawful right/entitlement to property

(ii)              Must be no fraudulent/dishonest intention 


(i)                 Event was not intended or foreseen

(ii)              Result was unforeseeable – was not a likely or foreseeable consequence of actions

Unwilled act

(i)                 Alternative to Accident

(ii)              Where Act/Omission occurs independently of  anaccused’s will 


(i)                 Sudden or extraordinary

(ii)              Objectively reasonable response to the circumstances as you believe them to be 

Alibi – Subject to notice requirement: CPA s 62

(i)                 Alibi evidence is evidence that an accused person was not present when an offence occurred and therefore could not physically have committed the offence.

(ii)              Particulars of the alibi evidence must be disclosed to the Prosecution at least 14 days prior to trial including the names and addresses of any alibi witnesses  


(i)                 The law presumes sanity, the presumption is rebuttable;  

(ii)              Requires proof of a recognised mental illness via medical expert diagnosis;

(iii)            Mental illness must render the person incapable of one of the following:

a.       Knowing what he or she is doing,

b.      Controlling their action,

c.       Incapable of knowing wrongfulness of their actions




Make an enquiry

Please fill in your details to have one of our staff contact you to discuss your case requirements.
  Appointments can also be made by contacting our office directly on 9221 2991

This field is for validation purposes and should be left unchanged.