The Legal Light Justin Stack The legal defence of self-defence Claiming that you killed or injured someone while acting in self-defence can be a legal defence in NSW. Section 418 of the Crimes Act 1900 states the accused must believe their actions were "necessary and reasonable". Criminal lawyer Reza Sedaghat at Stacks Law Firm says raising self-defence often occurs in local and other courts. It reverses the onus of proof, so it is the prosecution that must disprove "self-defence". A recent judgment in the NSW Supreme Court demonstrates how the self-defence law works. A woman's brother rushed to defend his sister from an attack by her ex-boyfriend, and in the fight reached for a knife on a kitchen bench and stabbed the ex, killing him. The brother argued he acted in defence of his sister, as the ex was saying he would kill her. The judge said she could not be satisfied "beyond reasonable doubt" the brother intended to kill the ex, and acted out of fear and panic. However, in arming himself with a knife, the brother departed from 'a reasonable response to the circumstances as he perceived them'. The brother was sentenced to six years and nine months in jail for "excessive self-defence manslaughter", with a non-parole period of four years and three months. Manslaughter has a maximum sentence of 25 years. Mr Sedaghat said under section 418 of the Crimes Act, a person is not criminally responsible for an offence if the person acts in self-defence. Section 421 says excessive self-defence is when the person dies, and the charge is reduced from murder to manslaughter. "The law says the person must believe the conduct was necessary to defend themselves or another person, and that conduct is what it defines as 'a reasonable response in the circumstances as he or she perceives them," Mr Sedaghat said. This was a "murder or manslaughter" case, but self- defence is most commonly argued in assault cases. Self-defence can be argued to prevent the unlawful deprivation of your liberty or that of another person. Self-defence can be argued when using "reasonable force" to protect property, but not if the defendant has used deadly force to protect property. "You can argue self-defence in the case of stopping a home intruder, but self-defence can only be argued until the person is no longer a threat to you or others. "It is hard to argue self-defence if you have chased them down the street, brought out a weapon, or continue fighting once the person is subdued and no longer a threat." Self-defence is a complex area of law and if the prosecution successfully argues the action was not reasonable or necessary, the defence can be lost. STACKS LAW FIRM Madaline Shepherd Licensed Conveyancer 02 6592 6592 taree.stacklaw.com.au Partners in life The Legal Light Justin Stack The legal defence of self - defence Claiming that you killed or injured someone while acting in self - defence can be a legal defence in NSW . Section 418 of the Crimes Act 1900 states the accused must believe their actions were " necessary and reasonable " . Criminal lawyer Reza Sedaghat at Stacks Law Firm says raising self - defence often occurs in local and other courts . It reverses the onus of proof , so it is the prosecution that must disprove " self - defence " . A recent judgment in the NSW Supreme Court demonstrates how the self - defence law works . A woman's brother rushed to defend his sister from an attack by her ex - boyfriend , and in the fight reached for a knife on a kitchen bench and stabbed the ex , killing him . The brother argued he acted in defence of his sister , as the ex was saying he would kill her . The judge said she could not be satisfied " beyond reasonable doubt " the brother intended to kill the ex , and acted out of fear and panic . However , in arming himself with a knife , the brother departed from ' a reasonable response to the circumstances as he perceived them ' . The brother was sentenced to six years and nine months in jail for " excessive self - defence manslaughter " , with a non - parole period of four years and three months . Manslaughter has a maximum sentence of 25 years . Mr Sedaghat said under section 418 of the Crimes Act , a person is not criminally responsible for an offence if the person acts in self - defence . Section 421 says excessive self - defence is when the person dies , and the charge is reduced from murder to manslaughter . " The law says the person must believe the conduct was necessary to defend themselves or another person , and that conduct is what it defines as ' a reasonable response in the circumstances as he or she perceives them , " Mr Sedaghat said . This was a " murder or manslaughter " case , but self- defence is most commonly argued in assault cases . Self - defence can be argued to prevent the unlawful deprivation of your liberty or that of another person . Self - defence can be argued when using " reasonable force " to protect property , but not if the defendant has used deadly force to protect property . " You can argue self - defence in the case of stopping a home intruder , but self - defence can only be argued until the person is no longer a threat to you or others . " It is hard to argue self - defence if you have chased them down the street , brought out a weapon , or continue fighting once the person is subdued and no longer a threat . " Self - defence is a complex area of law and if the prosecution successfully argues the action was not reasonable or necessary , the defence can be lost . STACKS LAW FIRM Madaline Shepherd Licensed Conveyancer 02 6592 6592 taree.stacklaw.com.au Partners in life