As a case passes through the criminal justice system in Canada and criminal defence lawyers discuss cases with defendants, you may hear the terms actus reus and mens rea mentioned.

An important concept in Canadian criminal law is “Actus non facit reum nisi mens sit rea”, which literally means “the act will not make a person guilty unless the mind is also guilty.”

In other words, for a person to be found guilty of a criminal offence, he/she must have committed an illegal act (actus reus) and had the required “state of mind” (mens rea) to commit the criminal offence.

This sounds simple but such matters can become quite complex and are often the topic of serious debate in criminal cases. It lies at the heart of the criminal justice system so it’s important to understand more about both terms, actus reus and mens rea.

Here’s what you need to know about actus reus.

What must the prosecution prove in criminal cases?

For the prosecution to achieve a guilty verdict in a criminal case, it must prove the actus reus and the mens rea beyond a reasonable doubt.

These elements are usually found in the corresponding offence section of the Criminal Code.

Actus reus means “guilty act” in Latin. Most people easily understand that for an individual to be convicted of a crime, the prosecution must prove that the actions or behaviour of the defendant caused the act to take place. A guilty act can be something a person does or omits to do.

The actus reus includes only voluntary bodily movements — generally those that society wants to prevent for the general good. If a defendant’s actions were “reflex” actions, the conduct does not satisfy the actus reus requirement.

For instance, if an individual walks into a bank with a gun and shouts: “Give me all the money!”, the actus reus is satisfied by the walking into the bank with a gun.

Additionally, to achieve a conviction for most crimes, the prosecution would usually need to prove beyond a reasonable doubt that the defendant had a guilty state of mind (mens rea) at the time. In such cases, whether or not the person knew the act was illegal is irrelevant because ignorance of the law is not a valid defence.

In the robbery example, the prosecution might show the court that planning had taken place in the days leading up to the execution of the robbery, for example.

Examples of mental states for different criminal offences include intention, willful blindness and criminal negligence.

• Intention is when an individual deliberately commits the actus reus.
• Willful blindness is when an individual knows of the possibility of illegality but chooses not to ask questions or investigate the situation.
• Criminal negligence is when an individual does not realize the consequences of his/her actions.

The elements of acts reus

The actus reus can consist of up to three separate elements:

1. The conduct (a voluntary act or omission)
2. The surrounding circumstances of the voluntary act
3. The consequences of the voluntary act

A good example is the offence of sexual assault. As outlined in section 271 of the Criminal Code, the actus reus of this offence includes the touching or threat of touching, the sexual nature of the touching and the absence of consent to the touching.

Omissions and actus reus

The actus reus requirement can also be satisfied by an omission when the individual had a duty to act and failed to fulfill that duty.

If an individual has a duty to look after young children, for instance, but gets busy at work and neglects them, failing to take adequate care so that they get sick and malnourished, the failure to act may be a guilty act (actus reus).

For criminal liability, an individual may have a duty to act because of any of the following reasons:

• A statute requires individuals to act in a certain way.
• A contract requires individuals to act in a certain way.
• A special status relationship exists that creates a duty to act in a certain way (e.g., parents must care for minor children).
• A voluntary assumption of care creates a duty to act in a certain way.
• The associated risk was caused by the individual.

Strict liability offences and actus reus

With strict liability offences, the prosecution only needs to prove the actus reus. There is no requirement to prove that the defendant had the mental state to commit the crime; only that the crime was committed.

These are often regulatory offences, which are not considered true crimes. Instead, they consist of actions that pose a threat to the general public. For these offences, an individual can be held criminally liable without his/her state of mind being taken into account.

A good example of a strict liability offence is speeding. This is an action that is considered dangerous to the public. There is no need to prove that the defendant intended to break the speed limit and endanger the public to convict him/her of this traffic offence.

Another example is a local business releasing pollutants into the river — the prosecution may not need to prove that the company intended to pollute, only that the pollution occurred (presenting a danger to the public).

Call us to arrange a confidential consultation

If you or a loved one is facing criminal charges, legal advice from a qualified lawyer can help protect your rights and clarify your options.

To speak with Cory Wilson or arrange a free, no-obligation consultation with Wilson Criminal Defence, call 403-978-6052 or email us here.