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 conf using because each different

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

of the specif‌ic crime. In 1889 Stephen J. indicated th at mens rea exists

only in relation to particul ar def‌initions of crime, so that,

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

case of theft, an i ntention 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 r eceiving 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 appear s confusing to cal l so many dissi milar 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 spec if‌ied what part icular

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

ual fault element to apply when no particular fault element i s speci-

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

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

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

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.

CRIMIN AL LAW152

forms t hat would bring greater clarity in determining fault elements,

but Parliament has not yet comprehensively def‌i ned the fault elements

required for crimes. As a result, t he 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 specif y 1) the circum stances and con sequences to

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

reus of t he 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 rea for murder requires at least sub-

jective knowledge that the v ictim would die. Similarly, stating that the

mens rea of m anslaughter i s objective tells only par t 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 understa nd 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 establi sh-

ing the fault element beyond a reasonable doubt.

1) The Relation of the Fault Element to the Prohibited Act

The fault element doe s not exist in the air or in the abstract but must

be related to certain consequences or circumstance s. As McLachlin J.

has stated,

Typically, mens rea is concerne d wit h the conseq uences 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 caus e death.3

On this principle, a person is not g uilty of assaulting a peace off‌icer

in the execution of his or her duties un less t he 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.) [Cre ight on] and di scussed below, note 5.

The Fault Element, or Mens Rea 153

rea for a ssault and subjective knowledge that the person is a p eace 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 ai med at s ymmetry between the mens rea and the prohibited

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

ity in Creight on 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 of fence must always attach to the precise consequence which is

prohibited as a matter of const itutional necess ity.5

In the result, McLach lin J. held that objective foresight of the r isk of

bodily harm was a suff‌icient fault element for the crime of unlawf ul

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 sometime s

called offences of partial intent, constructive crimes, or cr imes 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 requi re fault with respect

to t he 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].