THE murder charges levelled at Benjamin Batterham raise a difficult legal and ethical question - is it defensible to kill an intruder in your own home?
While the facts of the case will play out before the courts and can't be discussed here, we can explain the law and how it applies to circumstances like these - in general terms.
In NSW and indeed in all states of Australia there are four grounds under which a person can claim self-defence.
These are when you're worried someone is about to assault you or another person, when someone is trying to falsely imprison you, to protect a possession and to stop someone trespassing.
However Associate Professor of Criminal Law at Sydney University, Arlie Loughnan, said the law of self-defence in New South Wales was reformed in the early 2000s and under amendments to the Crimes Act a person can only use the trespassing defence when they've injured an intruder, not if they've killed them.
As Ms Loughnan explained, if you've killed an intruder who's broken into your house then the test becomes whether or not you've used excessive force and whether your actions were reasonable and necessary in the circumstances.
In cases where a homeowner has killed an invader the law in NSW provides a partial defence which leads to a charge of murder being downgraded to manslaughter but only under certain conditions - which Ms Loughnan explained.
"It would be up to a jury to decide whether they're persuaded that the defendant acted out of necessity in the circumstances," Ms Loughnan
Ms Loughnan said in all cases the amount of force used would have to be deemed reasonable.
"It's reasonable force as you perceive it," she said.
"That too would be for the jury to decide so if it was night time, if the intruder was taller than you -- these are all factors. The response has to be reasonable in the circumstances as you perceive them.
"Perception is important too so if the person had a stick but you thought it was a gun and you overreacted then the jury would have to consider the response as if the person had a gun."
Alastair Macadam from QUT's law school said the position was similar in Queensland.
However, under the Queensland Criminal Code, the defence that you acted to prevent someone trespassing on your property can only be used against very minor offences and not where grievous bodily harm has been inflicted.
"The bottom line is if someone comes into your house in the night and you wake up you can't just shoot them dead," Mr McAdam said.
He added if the intruder made a person fear for their safety, then it was legal to respond to the threat with force and that may include killing them.