Under Canada’s self-defence law, a person is allowed to defend themselves and their property from intruders, but the amount of force they use must be reasonable in the circumstances.
A high-profile incident in August 2025 sparked heated debate in Canada about the law of self-defence. A man apparently broke into an acquaintance’s home in a community outside Toronto. The intruder was taken to hospital with significant injuries apparently caused by the homeowner. Police charged the intruder with several property-related offences. Police also charged the homeowner with two serious offences of violence. The charges against the homeowner drew media attention and raised questions about what actions a homeowner can or cannot take against an intruder.
Canada’s Law of Self-Defence
After years of judges calling on Parliament to amend our confusing and inconsistent self-defence laws, Stephen Harper’s government finally changed the sections of the Criminal Code dealing with this defence in 2012. Section 34 of the Criminal Code now provides a step-by-step process for deciding whether an accused has lawfully acted in self-defence (or in defence of another person). Section 35 addresses the situation of defending one’s property. At the heart of both provisions is the concept of “reasonableness”.
Section 34 says that an accused is not guilty of an offence if they act on the reasonable belief that another person is using, or threatening to use, force against them (or another person). The accused must act for the purpose of defending themselves (or another person). Most importantly, the act must be “reasonable in the circumstances.”
The Code then lists factors the court must consider to decide whether the accused’s actions were reasonable (it is not a closed list – the court can also consider any other factor as it sees fit). These factors include:
- the nature of the force or threat;
- whether it was actually happening or was about to happen, and whether there was another option open to the accused;
- the role of the accused in the incident;
- whether any weapons were involved;
- the physical characteristics of the parties (their sizes, genders, ages and general physical conditions); and
- any history of violence or other relationship between the accused and the person attacking them.
The court must also consider the nature of the force used by the accused to defend themselves and whether it was proportionate to the situation. Finally, it is also relevant if the accused knew the force being used against them was itself lawful.
Section 35 sets out a similar (though slightly modified) framework for deciding whether an accused has committed an offence when defending their property. It too, however, is based upon the concept of “reasonableness.” This section says that if the accused acts upon the reasonable belief the other person has entered their property or has taken or damaged their property – or the other person is about to do any of these things – they may be found not guilty if they have acted to defend that property and their actions are reasonable in the circumstances.
Applying the Law of Self-Defence
It is, of course, difficult to know in advance how a particular “self-defence” case will unfold and be decided, but some real-life examples may help in understanding how these laws are applied.
A group of armed gang members attempt to break into a man’s home. As they try to come through a window, he is able to fend them off. In doing so, he stabs and seriously injures one gang member who made it inside. Instead of leaving the scene, the other gang members then try to break in through the accused’s door. Inside the home, the injured gang member repeatedly tries to get to the door to let his companions in. Each time he gets up, the accused stabs him again and tells him to stay down. After two or three different incidents, the injured man dies.
The accused is charged with murder, but the jury finds him not guilty. He was clearly acting in self-defence against a group of individuals who, by their words and actions, had intended to cause him serious harm or death. Even though the injured man was no longer a physical danger, he remained a real threat by trying to get to the door to allow his cohorts in so they could attack the accused. Everything the accused did was to defend himself from the gang which was trying to break into his apartment and attack him.
The outcome would have been very different, however, if the gang had not been trying to get through the door. If the others had simply left after the gang member was injured, the accused would likely have been convicted of murder if he had repeatedly kept stabbing the deceased long after he had stopped being a threat. In such a situation, the use of force by the accused would not have been reasonable.
In another scenario, a father must use physical force to defend himself and his wife from their adult son, who is larger and stronger than his elderly parents. As he does from time to time, the son has worked himself into a rage and begins to attack his mother. His father grabs the son from behind and holds him with his arm around the son’s neck until his son stops struggling. Wanting to be sure the son will not become violent again if he releases him, the father continues to hold him in this position for a couple more minutes. Unfortunately, this is enough time for the son to stop breathing, and he dies. The father is charged with manslaughter, but after considering all of the circumstances a judge finds him not guilty. The history of threats and assaults by the son against his parents; the mis-match between them in terms of age, size and physical abilities; and the fact the parents had not done or said anything which might reasonably have put the son in a position where he thought he needed to use physical force against them all support the judge’s finding.
Changing any of those factors, however, might have led to a very different outcome. If the father had been larger than the son, and had not been as elderly as he was; had the son not begun to use physical violence against his mother; had the son immediately calmed down and apologized as soon as his father had his arm around the son’s neck – any of these changes in the situation might well lead the judge to conclude that the use of force went beyond what was reasonable in the circumstances, and the accused might have been found guilty.
The Role of the Accused
In deciding whether an accused was acting in legitimate self-defence, it is important for the court to consider whether the accused’s actions led to a situation where they had to use force against another person. In 2016, a man named Peter Khill saw someone breaking into his vehicle parked outside his home. Instead of calling the police, Khill took his loaded shotgun, went out and confronted the man. Khill told the man, “Hands up.” As the man turned towards him, Khill fired two quick shots at the man. He fired at least one shot when the man was still facing towards the inside of the truck and not towards Khill. Khill was charged with murder. He claimed he was acting in self-defence because he thought the man had a gun (he did not) and also because he thought the man might later try to break into his home.
The court acquitted Khill at his first trial. The Supreme Court of Canada later ruled there should be a new trial because the lower court had not properly addressed the issue of Khill’s own conduct leading up to the incident. The Supreme Court said that to decide whether or not the accused’s use of force was reasonable, a jury would have to consider carefully whether the accused helped create the situation where he felt he had to commit an otherwise unlawful act to defend himself. In this case, since Khill decided to arm himself and confront the apparent burglar instead of staying in his house and calling the police, the scenario unfolded mostly as a result of his actions. At a later re-trial, a jury found him guilty of manslaughter.
The Limits of Self-Defence
However simple and straightforward we might think a “self-defence” argument should be, the law requires courts to carefully analyse the facts of the case and properly apply the legal test. At the heart of the case will always be the concept of “reasonableness”. The courts have cautioned that using force – especially lethal force – against another person is not to be encouraged and should not be allowed to become the usual response to any possible danger or threat.
Returning to the August 2025 case, only a court hearing all of the evidence about the actions of both the intruder and the homeowner will be able to decide whether the homeowner acted in self-defence. Even though we do not know exactly what happened here, some of the public commentary on this case has suggested that anyone who breaks into another person’s home can and should simply be shot, but that is not the law in Canada. Anyone who listens to and acts upon such provocative statements does so at their own serious peril.
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DISCLAIMER The information in this article was correct at time of publishing. The law may have changed since then. The views expressed in this article are those of the author and do not necessarily reflect the views of LawNow or the Centre for Public Legal Education Alberta.
About Charles Davison
