The Fault Element, or Mens Rea

• Author: Kent Roach
• Profession: Faculty of Law and Centre of Criminology. University of Toronto
• Pages: 151-193

151

CHAPTER 5

THE FAULT ELEMENT,

OR

MENS REA

Generic references to mens rea are confusing because each different

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

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

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

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

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

to have forcible connection wit h a woman without her consent; and

in the case of receiving stolen goods, k nowledge 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 state s 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.2 It has also not provided a resid-

ual fault element to apply when no particular fault element is speci-

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

all aspects of the actus reus. Numerous proposals have called for re-

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

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

for clear def‌init ions of separate offences of intent ional and negligent arson.

CRIMINAL LAW152

forms that would bring greater clarity in determining fault elements,

but Parliament 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 accurately,

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 precise

approach would be to say the mens reafor murder requires at least sub-

jective 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 negligence

should also be explained, as should who is the reasonable person used

to apply the objective fault or negligence standard.

It is also important to understand the differences between constitu-

tional requirements and common law presumptions of particular forms

of men s rea and how the so-called defences of intoxication and mistake

of fact are really conditions that prevent the prosecutor from establish-

ing 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 wit h the consequences of the pro-

hibited actu s reus. Thus, in the crimes of homicide, we speak of the

consequences of the voluntary act — intent ion to cause death, or

reckless a nd wilfully blind persistence in conduct which one knows

is likely to cause death.3

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

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

absolute rule, as s een in her own majority judgme nt in R. v. Creighton (1993), 83

C.C.C. (3d) 346 (S.C.C.) [Creighton] and di scussed below, note 5.

The Fault Element, or Mens Rea153

rea for assault and subjective knowledge that the person is a peace of-

f‌icer. 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.4 The fau lt ele -

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

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

itionally aimed at symmetry between the mens reaand the prohibited

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

ity in Creighton concluded:

It i s important to d istinguish between cri minal law theory, which

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

rea and the const itutional requirements of the Charte r . . . .

I know of no authority for the proposit ion that the me ns rea of

an offence must always attach to the precise consequence which is

prohibited 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 prohibited act of killing and did not satisfy the constitutional

requirement that a murderer at least have subjective foresight of death.6

4 R. v. Hess (1990), 59 C.C.C. (3d) 161 (S.C.C.), discu ssed 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 of fences punish a person more

severely becau se of the consequences of his or her a ctions even though there is

no fault requireme nt with regards to those ag gravating consequence s. Examples

cited included “ma nslaughter (s. 222(5)), crimin al negligence causing bodi ly

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

causing bod ily harm (s. 249(3)), dangerous operat ion causing death (s. 249(4)),

impaired dr iving causing bod ily harm (s. 255(2)), impaired driv ing causing

death (s. 255(3)), assault caus ing bodily harm (s. 267(1)(b)), aggravated ass ault

(s. 268), sexual assault cau sing bodily harm (s. 272(c)), aggra vated sexual

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

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

an error to suppos e that actus reus and me ns rea always match in thi s neat way.”

6 R. v. Martineau(1990), 58 C.C.C. (3d) 353 (S.C.C.) [Martineau].