The Fault Element, or Mens Rea

• Author: Kent Roach
• Profession: Faculty of Law and Centre of Criminology University of Toronto
• Pages: 141-183

Generic references to mens rea are confusing because each different

crime has a specific fault element which must be related to the actus

reus of the specific crime. In 1889 Stephen J. indicated that mens rea

exists only in relation to particular definitions of crime, so that:

“Mens rea” means in the case of murder, malice aforethought; in the

case of theft, an intention to steal; in the case of rape, an intention to

have forcible connection with a woman without her consent; and in

the case of receiving stolen goods, knowledge that the goods were

stolen. In some cases it denotes mere inattention. For instance, in the

case of manslaughter by negligence it may mean forgetting to notice

a signal. It appears confusing to call so many dissimilar states of mind

by one name.1

In Canada, confusion about mens rea continues because Parliament has

not clearly and consistently defined fault elements such as “purposely,”

“knowingly,” “recklessly,” or “negligently” or specified what particular

fault element applies for each offence.2It has also not provided a resid-

ual fault element to apply when no particular fault element is specified

or provided a general rule that the fault element should relate to all

aspects of the actus reus. Numerous proposals have called for reforms

141

The Fault Element,

or

Mens Rea

chapter 4

1R. v. Tolson (1889), 23 Q.B.D. 168 at 185 (C.C.R.) [Tolson].

2 But see Criminal Code of Canada, R.S.C. 1985, c. C-46, ss. 433 and 436 [Code],

for clear definitions of separate offences of intentional and negligent arson.

that would bring greater clarity in determining fault elements, but Par-

liament has not yet comprehensively defined the fault elements

required for crimes. As a result, the fault element must still be inferred

from the legislative definition of each separate offence.

A. Conceptual Considerations

In order to explain the fault element of any criminal offence accurate-

ly, it is necessary to specify 1) the circumstances and consequences to

which the fault element is directed, including its relation to the actus

reus of the offence, and 2) the precise fault element required. It is not

very helpful to say the mens rea for murder is subjective. A more pre-

cise approach would be to say the mens rea for murder requires at least

subjective knowledge that the victim would die. Similarly, stating that

the mens rea of manslaughter is objective tells only part of the story.

The fault is objective foreseeability of bodily harm. The degree of neg-

ligence should also be explained, as should who is the reasonable per-

son used to apply the objective fault or negligence standard.

It is also important to understand the differences between consti-

tutional requirements and common law presumptions of particular

forms of mens rea and how the so-called defences of intoxication and

mistake of fact are really conditions which prevent the prosecutor from

establishing the fault element beyond a reasonable doubt.

1) The Relation of the Fault Element to the Prohibited

Act

The fault element does not exist in the air or in the abstract, but must

be related to certain consequences or circumstances. As McLachlin J.

has stated:

Typically, mens rea is concerned with the consequences of the prohib-

ited actus reus. Thus, in the crimes of homicide, we speak of the con-

sequences of the voluntary act — intention to cause death, or reckless

and wilfully blind persistence in conduct which one knows is likely

to cause death.3

142 Criminal Law

3R. v. Théroux (1993), 79 C.C.C. (3d) 449 at 458 (S.C.C.) [Théroux]. This is not

an absolute rule, as seen in her own majority judgment in R. v. Creighton

(1993), 83 C.C.C. (3d) 346 (S.C.C.) [Creighton] and discussed below, note 5.

On this principle, a person is not guilty of assaulting a peace officer in

the execution of his or her duties unless the accused has the mens rea

for assault and subjective knowledge that the person is a peace officer.

Similarly, the Court classified the old offence of statutory rape as

absolute liability because Parliament had excluded fault in relation to a

crucial aspect of the actus reus, namely the age of the girl.4The fault ele-

ment should generally extend to all the elements of the prohibited act.

The Supreme Court has recognized that the criminal law “has tra-

ditionally aimed at symmetry between the mens rea and the prohibited

consequence of the offence” as discussed above. Nevertheless, a major-

ity in Creighton concluded:

It is important to distinguish between criminal law theory, which

seeks the ideal of absolute symmetry between the actus reus and mens

rea and the constitutional requirements of the Charter. . . .

I know of no authority for the proposition that the mens rea of an

offence must always attach to the precise consequence which is pro-

hibited as a matter of constitutional necessity.5

In the result, McLachlin J. held that objective foresight of the risk of

bodily harm was a sufficient fault element for the crime of unlawful act

manslaughter, even though the actus reus of the crime was causing

death as opposed to causing bodily harm. Offences that do not require

a fault element in relation to all aspects of the actus reus are sometimes

called offences of partial intent, constructive crimes, or crimes based

on predicate offences.

Constructive murder violates section 7 of the Charter because

while it required the fault of a predicate offence (such as robbery) and

the fault of causing bodily harm, it did not require fault with respect to

The Fault Element, or Mens Rea 143

4R. v. Hess (1990), 59 C.C.C. (3d) 161 (S.C.C.) discussed in chs. 1 and 5.

5 Above note 3 at 378–79. In R. v. DeSousa (1992), 76 C.C.C. (3d) 124 at 141

(S.C.C.) [DeSousa], the Court noted a number of offences punish a person more

severely because of the consequences of his or her actions even though there is

no fault requirement with regards to those aggravating consequences. Examples

cited included “manslaughter (s. 222(5)), criminal negligence causing bodily

harm (s. 221), criminal negligence causing death (s. 220), dangerous operation

causing bodily harm (s. 249(3)), dangerous operation causing death (s. 249(4)),

impaired driving causing bodily harm (s. 255(2)), impaired driving causing

death (s. 255(3)), assault causing bodily harm (s. 267(1)(b)), aggravated assault

(s. 268), sexual assault causing bodily harm (s. 272(c)), aggravated sexual

assault (s. 273), mischief causing danger to life (s. 430(2)), and arson causing

bodily harm (s. 433(b)). As noted by Professor Colvin, ‘[i]t would, however, be

an error to suppose that actus reus and mens rea always match in this neat way.’”