Self Defence: How Does It Work?


What Is Self-defence?

Self-defence is a well-known defence in Canadian law justifying the use of force to repel an attack. It is an ancient common law that was incorporated into the first Canadian Criminal Code in 1892. The authors of 1879 Report of the Criminal Code Bill Commission, which formed the basis for the inclusion of the defence in the Criminal Code,recognized one’s right to defend oneself when they stated:

The law discourages persons from taking the law into their own hands. Still the law does permit men to defend themselves …And when violence is used for the purpose of repelling a wrong, the degree of violence must not be dis proportioned to the wrong to be prevented, or it is not justified.


In 2012 the Citizen’s Arrest and Self-defence Act came into force. This Act drastically reshaped the law of self-defence in Canada. Presently, the defence is governed by the following principles:

  1. (1) A person is not guilty of an offence if

(a) they believe on reasonable grounds that force is being used against them or another person or that a threat of force is being made against them or another person;

(b) the act that constitutes the offence is committed for the purpose of defending or protecting themselves or the other person from that use or threat of force; and

(c) the act committed is reasonable in the circumstances.

So What Does That Really Mean?

In order to successfully raise the defence of self-defence you must present evidence on three different variables, which are explained below. If there is some evidence with respect to each factor, then the Crown must disprove self-defense beyond a reasonable doubt. That is, the Crown must prove that you did not act in self defence.

The first factor that will be considered is whether or not you reasonably believed that force was being used against you (i.e. that you are being attacked) or another person (i.e. that another person is being attacked). Alternatively, you could also believe there to be the threat of force (i.e. you are being threatened with an attack) without actually having force applied against you. This belief that you are being attacked must also be reasonable to an outside observer.

Another factor that will be considered is whether or not your actions were truly for the purpose of defending yourself or another person from an attack. That is, even if someone else hits you first, if you hit them back out of revenge or spite your actions will not be considered to be self-defence.

Similarly, the third factor that will be considered is whether or not your actions were reasonable in the circumstances. There are a number of variables under this factor which the Court will consider including the attack or threat you are defending against, your response, whether there were other options available to you, any history of “bad-blood” between the parties, whether the attack was provoked by yourself, and, most importantly, whether your response was proportional in the circumstances. For example, if you stabbed someone to death after they shook their fist at you, that would not likely be found to be proportional in the circumstances and any claimed defence of self-defence would likely not be successful.

Again, if the Crown is unable to disprove self-defence beyond a reasonable doubt then the accused will be justified in their actions and found not guilty of the charge against them.

What You Should Know If You’ve Been Charged

As you can see, the defence of self-defence is very fact specific. If you’ve been charged with a criminal offence, and you believe you were acting in self-defense, give one of the many experienced lawyers at Liberty Law a call and they will help evaluate your case.

Some other important things to remember when charged with a criminal offence it to not discuss your case with anyone other than your criminal lawyer. Discussions with your lawyer are confidential. Discussions with anyone else are not.

Do not vent about your case on social media or discuss it in any fashion on other public forums. These public forums are available to the police and prosecutor alike and may be used against you. Even comments which do not directly talk about your case but tend to show an animus about other individuals involved in your case may affect your credibility as a witness an ultimately lead to your conviction.  

For a free consultation about your case, feel free to call us toll-free at 1-877-277-4766. We can also be reached by email at

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