Self-Defence to an Assault Charge

The short answer

Self-defence is a full defence to assault. If it applies, you are not guilty. The test is set out in s. 34 of the Criminal Code, and it applies to every assault charge, from common assault to aggravated assault.

You do not have to prove you acted in self-defence. If there is evidence that makes it a real possibility, the Crown must prove beyond a reasonable doubt that it does not apply.

The three-part test

Section 34(1) asks three questions, and all three must be met:

1. Belief: Did you believe, on reasonable grounds, that force or a threat of force was being used against you or someone else?
2. Purpose: Did you act to defend or protect yourself or that person? Acting out of revenge or anger does not count.
3. Reasonableness: Was what you did reasonable in the circumstances?

The third question is usually the hardest one to answer.

What makes a response reasonable

The court looks at all the circumstances. Section 34(2) lists factors, including:

• The nature of the force or threat.
• How close the danger was, and whether there were other ways to respond.
• Your role in the incident.
• Whether anyone used or threatened to use a weapon.
• The size, age, gender and physical abilities of the people involved.
• The history between you, including past violence or threats.
• Whether your response was proportionate to the threat.

You do not have to measure your response exactly. Courts recognize that people in danger react quickly. However, the response cannot go far beyond what the situation called for.

For example, pushing someone away after they swing at you is likely to be seen very differently from continuing to hit them after they are on the ground. Self-defence can be raised to any assault charge, including assault causing bodily harm, but the more serious the injury, the more closely the court will examine whether the response was reasonable.

Defending someone else

The same test applies when you defend another person. For example, stepping in to protect a friend or a family member who is being attacked can be self-defence, if your belief and your response were reasonable.

When self-defence does not apply

• After the threat has ended: Force used once the danger is clearly over is not defending anyone.
• Revenge: Hitting back later, to get even, is not self-defence.
• Against police acting lawfully: Self-defence generally does not apply to force used against a police officer doing their duty, unless you reasonably believe the officer is acting unlawfully (s. 34(3)).

Do you have to retreat?

There is no strict duty to retreat. However, whether you could have safely walked away is one of the factors the court considers.

If you started it

Self-defence can still apply even if you were involved in starting the conflict. However, your role is a factor, and it can make the defence harder. For example, if someone starts a shoving match and the other person pulls a knife, defending against the knife may still be reasonable.

Self-defence in relationships

Self-defence can apply in intimate partner cases, including where both people were charged after an argument. The history between the partners, including past violence or threats, is one of the listed factors in s. 34(2). That history can help explain why a person reasonably believed they were in danger, even when the other person's actions might look minor to an outsider.

Building a self-defence case

Evidence matters in a self-defence claim. Useful evidence can include:

• Security, phone or doorbell video, which is often deleted within days, so act fast.
• Photos of your injuries, damaged clothing or the scene.
• Witnesses who saw the start of the incident.
• Medical records showing your own injuries.
• Texts or messages showing past threats.

Get advice before giving a statement to police. Explaining self-defence clearly matters, and a rushed statement can hurt the defence.

How self-defence is raised in court

Self-defence can be raised at trial through cross-examination of the Crown's witnesses, through defence witnesses or through your own testimony. Before trial, a lawyer can also present the self-defence evidence to the Crown, which sometimes leads to a withdrawal. Whether you should testify is an important decision that depends on the rest of the evidence.

Self-defence and weapons

When a weapon is involved, the court looks especially closely at whether the response was reasonable. Section 34(2) specifically lists whether any party used or threatened to use a weapon as a factor. Using a weapon against an unarmed person is usually much harder to justify, while defending yourself against someone who has a weapon may allow a stronger response, depending on all of the circumstances.

Statements to police

People who acted in self-defence often want to explain themselves to police right away, because they feel they did nothing wrong. However, statements given in the stress of the moment can contain mistakes, leave out important details or be misunderstood. It is usually safer to speak to a lawyer first, so that your account is presented clearly, at the right time and in a way that supports the defence.

Possible outcomes

When both people are charged

Sometimes police charge both people after a fight, especially when each person says the other started it. In these cases, self-defence evidence is often the key issue. Video, witnesses and injuries can help show who used force first and why.

What to do now

• Save any video, photos and messages right away.
• Write down the names of witnesses who saw the start of the incident.
• Get legal advice before you speak to police.

Self-defence and young people

The same self-defence test applies to young people charged under the Youth Criminal Justice Act. The court considers the age and size of the people involved when deciding whether the response was reasonable.

How we can help

We can review the evidence, help preserve video and witnesses early, and present self-defence to the Crown or at trial. Call (647) 223-1980 for a free consultation.

Frequently asked questions