What is self-defence and when can it be used?

Simply put, self-defence is a defence to the criminal offence of assault. If you use force to stop an attacker, self-defence may apply. The burden of proof is on the crown to prove that self-defence is unavailable in the circumstances, rather than on the accused. Section 34 of the Criminal Code of Canada sets out the requirements for the use of self-defence, which is laid out in 3 elements. First, the accused must reasonably believe that force or the threat of force is being used on themselves or another. Second, the purpose of the force must be to protect themselves or others. Finally, the act must be reasonable in the circumstances. Although the availability of the accused to retreat does not necessarily mean self-defence is not an option, it will be taken into consideration by the court when deciding whether the force was justified.


There are both subjective and objective elements of this defence. The court will look objectively at the accused state of mind when the act was committed, taking into consideration that “hindsight is 20/20” and the accused may not have acted in the most appropriate way possible due to the fact that they didn’t have time to think about and assess the situation. The court will look at the specific circumstances in the case before them to determine the accused state of mind and whether they believed the action was reasonable. Therefore, the court will take into account how the accused saw the situation to determine if they truly thought there was a risk, and whether they believed the action they took was reasonable. The subjective analysis will involve considering whether, in the circumstances, a reasonable person would have reacted the same way. Self-defence can also include the fact that the accused mistakenly thought there was more danger than there was. For example, the accused thought the attacker was armed.


Even in the case of defending your home from an intruder, the use of self-defence can only be used if the amount of force used to deter the intruders was reasonable. Defence from intruders entering your home is found in section 35 of the Criminal Code of Canada, which states that it is not an assault by criminal standards if the accused believed on reasonable grounds that someone was about to enter the property illegally and intends to damage or steal property. However, even if you have a legal right to attempt to deter the intrusion, this does not mean you can do so by any means necessary. Again, the defence is only available if the act committed was reasonable in the circumstances, which will be assessed by the courts.


If you have been charged with assault, it is important to seek legal advice immediately in order for a lawyer to review your case and determine any possible legal defences.


Ron Ellis is a criminal defence lawyer based in London, Ontario and practices criminal defence law all over Southwestern Ontario, including Grand Bend, Sarnia, Woodstock and Kitchener.

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