2.7B defences to murder

• When charged with a homicide (e.g. murder, manslaughter or infanticide), the accused can choose to use a defense in an attempt to justify their actions either completely or partially.
• defences to homicide

  • self defence
  • mental impairment
  • involuntary actions
  • sudden or extraordinary emergency
  • duress
• self defence - crimes act 1958

  A person is not guilty of murder if he or she carries out the conduct that would otherwise constitute murder while believing the conduct to be necessary to defend himself or herself or another person from the infliction of death or really serious injury. 
• self defence - what the accused most prove

  1. Accused had a belief that it was necessary to act to defend themselves or another from serious injury 
  2. Accused's actions were reasonable in the circumstance as they perceived them
• mental impairment - full defence

  This defence implies that when the accused can show they were suffering from a mental impairment at the time of the offence took place
• mental impairment - full defence

  The accused did not know what they were doing because they had little understanding of the nature of their actions

  OR

  Did not know the conduct was wrong or could not reason or think about their conduct like an ordinary person
• mental impairment - full defence

  • If proven they will be found not guilty due to mental impairment
• Involuntary actions- Automatism (full defence)

  This defence refers to the automatic, involuntary actions of a person that are not caused by a disease of the mind (mental impairment)
• involuntary actions- Automatism (full defence)

  For the accused to be acquitted on the basis of automatism they must prove: 

  1. The act was involuntary, done by muscles without any control of the mind

  AND

  1. Done by a person who was not conscious of what they were doing, e.g. concussion or sleepwalking
•  Involuntary actions - Intoxication

  According to common law, gross intoxication is a way of proving that the accused acted involuntarily and that the men's rea cannot be established
• Involuntary actions - Intoxication

  The defence is rarely successful as the level of intoxication required to make a person's actions involuntary is extreme
• involuntary actions - intoxication

  • The defence can be raised in relation to other defences
  • If the accused is responsible for being intoxicated the court will not take this into account
• duress - under duress


  threat or harm to yourself or others if you don't commit murder