The Prohibited Act, or Actus Reus

• Author: Kent Roach
• Pages: 92-142

92

CHAPTER 3

THE PROHIBITED ACT,

OR

ACTUS REUS

The actus reus, or prohibited act, is def‌ined by the legislation creating

the specif‌ic crim inal or regulatory offence. In order to ensure that there

is f‌ixed predetermined law, the courts cannot create crimes on their

own. For similar reasons, the Charter1provides important protections

against vague or retroactive criminal laws. For example, laws may be

struck down under section 7 of the Charter if they are so vague that

they do not provide fair notice of what is prohibited, or any limita-

tion on law enforcement discretion. Retroactive criminal laws would

also violate section 11(g) of the Charter because they would fail to give

people fair notice of the act or omission that is prohibited and section

11(i) similarly protects against retroactive punishments.

Although legislatures def‌ine the prohibited act, courts play an im-

portant role in interpreting the words used to def‌ine crimes. The deter-

mination of the precise scope of the prohibited act is largely a matter of

statutory interpretation. Courts will interpret all statutes in a manner

designed to achieve their purposes, but in cases of reasonable ambigu-

ity, they will resort to a doctrine of strict construction of the criminal

law that will favour the liberty of the accused as well as the need for

clarity and fair notice in def‌ining what is prohibited. This is also con-

sistent with the ideal of a f‌ixed predetermined law that clearly alerts

people to what is prohibited.

1 Canadian Char ter of Rights and Freedoms, Part I of the Constit ution Act, 1982, be-

ing Schedule B to th e Canada Act 1982 (UK), 1982, c 11 [Charter].

The Prohibited Act, or Actus Reus93

The ideal of a f‌ixed, predetermined law should in theory allow

citizens to determine beforehand whether conduct is illegal. This is

important because the criminal law has traditionally not allowed ig-

norance or mistakes about the law to be an excuse for a crime. Section

19 of the Criminal Code provides that ignorance of the law is not an

excuse. This generally means that a mistaken belief by accused that

their actions are legal wi ll not be a defence to a cr ime whereas mistakes

about the existence of essenti al facts can be an excuse that wi ll prevent

the prosecution from establishing mens rea. There are limited excep-

tions to this rule with respect to off‌icially induced error and particular

forms of mens rea for theft and fraud that allow accused to argue that

they were acting with a “colour of right” in that they t hought they were

legally entitled to take property. This chapter will examine not only

the prohibited act, but the related principle that legal ignorance or mis-

takes are not excuses.

In order to obtain a conviction for a criminal or a regulatory of-

fence, the Crown must always prove beyond a reasonable doubt that

the accused committed the prohibited act (actus reus).2 The actus reus

is only one element of a criminal offence. In theory, the prohibited act

must coincide with the fault element, or mens rea, for a crime to be

committed. It will be seen in this chapter that the courts have some-

times f‌inessed this requirement, often by def‌ining the criminal act in a

broad fashion so that it overlaps with a time in which the accused had

the required fault element.

Although the crimin al law generally keeps the physical and mental

elements of crimes di sti nct, an emerging line of authority suggests that

an accused who acts involuntarily may not have committed an actus

reus. This interpretation effectively builds a minimal mental element

into the actus reus. As a practical matter, it could prevent the court

from convicting an accused who acted in an involuntary and uncon-

scious manner even though the offence may have no fault element or

one based on negligence. The accused can raise a defence of accident

as a means to raise a reasonable doubt about the voluntariness of the

criminal act.

Sometimes when determining whether the accused has committed

the actus reus, it is necessary to determine if he or she caused s ome pro-

hibited result. Causation is def‌ined broadly in homicide cases so that

an accused may be held to have caused another’s death even though

2 The Supreme Court has he ld that it is an error of law for the tr ial judge to in-

struct the jur y that they must f‌ind an unl awful act. R v Gunning, 2005 SCC 27 at

paras 30 –31 [Gunning].

CRIMIN AL LAW94

other factors, such as lack of medical treatment or the victim’s “thin

skull,” contributed to the death. This approach f‌its into the trend to-

wards expansive def‌initions of the criminal act.

The criminal law has traditionally been reluctant to punish an

omission or a failure to act, but some criminal and regulatory offences

punish people for failing to act or to fulf‌ill specif‌ic legal duties. The

Criminal Code tends to impose duties on specif‌ic groups of persons

such as parents and guardians and not the public at large. For example,

it is an offence for parents and guardians to omit or fail to provide chil-

dren with the neces sities of life,3 but it is not a crime for a person not to

take reasonable steps to help a stranger in peril.

Finally, this chapter will examine how the actus reus or prohibited

act as initially enacted by the legislature and then interpreted by the

courts has important policy components. For example, in 1983 the of-

fence of rape, which was def‌ined as non-consensual sexual intercourse

by a man with a woman who was not his wife, was replaced with the

broader, gender-neutral offence of sexual assault that applied to all per-

sons. In 1992 the law of sexual assault was again changed, with Parlia-

ment def‌ining consent and stating specif‌ic instances in which consent

did not exist. The Supreme Court subsequently decided that for pur-

poses of determining the actus reus, consent should be based on the

subjective views of the complainant. In 2018, Parliament returned to

the def‌inition of the actus reu s of sexual assault. Bill C-51 provides that

no consent is obtained if the complainant is unconscious or otherwise

incapable of consenting and that consent must be present at the time

of the sexual activity. It also stated that a number of situations where

consent is claimed are que stions of law,4 thus making cle ar that section

19 of the Code prohibiting ignorance or mistakes of law applied.

Courts also contribute to the policies that inform different def‌in-

itions of the actus reus. Examples include the Supreme Court’s deci-

sion that consent for the purpose of assault will be nullif‌ied or vitiated

for reasons of public policy when serious bodily harm is intended and

caused.5 This r uling had the effect of turning some consensual f‌ist f‌ights

into assaults. Finally, the broad nature of many of the prohibited acts

3 Criminal Code, RSC 1985, c C-46, s 215 [Code].

4 Bill C-51, An Act to Amend the Criminal Cod e and the Department of Just ice Act

and to Make Conseque ntial Amendments t o Another Act, 1st Sess, 42nd Parl, 2017,

proposed s 273.1 (in committee, Senate).

5 R v Jobidon, [1991] 2 SCR 714 [Jobidon]; R v Paice, [2005] 1 SCR 339 [Paice].