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).
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