It is well recognised that two of the most fundamental legal principles are the right to life and the right to own property. What happens when these two principles conflict? This possibility exists within the realm of criminal law where an individual may be acquitted for killing in defence of property.
In certain Australian states, there are home invasion provisions that govern the doctrine of self-defence and defence of property. There is no specific home invasion legislation in New South Wales, except for self-defence under the Crimes Act 1900 (NSW) and the common law.
The law of self-defence in New South Wales is stated in Part 11 of the Crimes Act 1900 (NSW). The test for self-defence is set out in section 418 of the Crimes Act 1900 (NSW) and was judicially considered by Howie J in R v Katarzynski  NSWSC 613 and structured as a two part test:
The first issue is determined from a completely subjective point of view…. The second issue is determined by an entirely objective assessment of the proportionality of the accused’s response to the situation the accused subjectively believed he or she faced.
Section 420 of the Crimes Act 1900 (NSW) removes self-defence in cases concerning only protection of property or prevention of criminal trespass where the defendant intentionally or recklessly caused death. A major amendment was section 421 of the Crimes Act 1900 (NSW), which implemented excessive self-defence in limited circumstances concerning the defence of an individual or to prevent the unlawful depravation of liberty and not in cases of defence of property or against trespass alone.
While decided before the 2002 amendments to the Crimes Act 1900 (NSW), R v Munro  NSWSC 1168 is a significant case concerning the complexities and issues concerning self-defence, defence of property and the previous application of the now repealed Home Invasion (Occupants Protection) Act 1998 (NSW). In Munro, the offender attacked and killed the victim who lived next door. The victim and his brother entered Munro’s backyard armed with a cricket bat. Munro had disarmed the victim and struck him with the bat. The victim attempted to run away but Munro did not cease in his attack, causing the victim to collapse. The victim consequently suffered a skull fracture and an underlying subdural subarachnoid haemorrhage and died shortly after. The offender was charged with murder.
Badgery-Parker AJ found that the deceased was an intruder for the purpose of the Home Invasion (Occupants Protection) Act 1998 (NSW) and that the Crown successfully proved beyond reasonable doubt that Munro’s continued attack on the deceased far exceeded the defence available under the Home Invasion Act 1998 (NSW) and self-defence under the common law (continued lethal force was not proportional to the situation).
Essentially, it is lawful and permissible under the Crimes Act 1900 (NSW) for a person to use reasonable force to protect his/her own property provided it is necessary and proportional. This will involve an analysis of the facts and circumstances of each individual case.