1b. Mens Rea

Summary of law on Mens Rea #

General points on mens rea: #

There is no single kind or level of fault that applies to all criminal or regulatory offences.

The Supreme Court has held that it is a principle of fundamental justice under section 7 of the Charter that a person should not be convicted of a criminal offence without the Crown having to prove a fault element, and one that is proportionate to the gravity of the offence. (Creighton)

Section 7 does not therefore require that a conviction for a criminal offence rest on proof of subjective mens rea. It requires proof of a fault element, and the fault element need only attach to a blameworthy element of the actus reus. For most crimes, objective mens rea is constitutionally sufficient, so long as it is commensurate to the gravity of the offence. (DeSousa, Creighton)

‘Special stigma crimes’ are a partial exception. The Court has identified a category of offences to be ‘special stigma’ offences, based on their stigma and penalty. In Vaillancourt, the Court held that it is a principle of fundamental justice that a person cannot be convicted of such an offence without proof of “a mens rea reflecting the particular nature of the crime.” For theft: proof of dishonesty; for murder: proof of subjective foresight of death.

In the case of a negligence-based criminal offence, section 7 requires proof of the accused’s failure to be aware of a risk arising from conduct amounting to a marked departure from the standard of the reasonable person. (Creighton)

Section 7 requires that any offence that may result in a deprivation of liberty (jail, probation) cannot be an absolute liability offence. A regulatory offence with penal consequences must either require proof of fault or allow for proof of a lack of fault (as in strict liability). (BC Motor Vehicle Reference)

Common law presumptions about the fault element: #

Where an offence provision is silent on mens rea, the common law presumes that a certain level of fault is required, depending on whether the offence is criminal or regulatory in nature.

-an offence can be inferred to be “criminal” where it:

-carries a serious penalty or stigma; and/or

-absolutely prohibits and punishes inherently wrongful conduct.

-an offence can be inferred to be “regulatory” where it:

-appears in either a provincial or federal statute;

-its predominant purpose is the regulation of a risk or the prevention of harm to public welfare through the requirement to abide by a minimum standard of care or conduct; and

-carries a relatively low penalty and stigma (i.e., a jail sentence of roughly 3 years or less)

(Beaver, Pierce, Sault Ste. Marie, Wholesale Travel)

Offences in the Criminal Code are presumed to be criminal. (Prue, Buzzanga) The same presumption arguably extends to offences in other criminal law statutes such as the CDSA and the YCJA.

If an offence is a criminal offence and is silent as to mens rea, there is a presumption at common law that the offence requires the Crown to prove a subjective form of mens rea (intent, knowledge, willful blindness or recklessness) for each element of the actus reus. (Sault Ste. Marie, Buzzanga, R v ADH [SCC 2013])

In the case of offences (aside from murder) that include aggravated assault, unlawful act causing bodily harm and unlawful act manslaughter, the Supreme Court has held that a distinct fault element may attach to the assault or unlawful act (subjective or objective mens rea, as the case may be), but the fault element in relation to the prohibited consequence (bodily harm, death, etc.) may be as low as ‘objective foreseeability of non-trivial harm.’ (DeSousa, Creighton)

If the offence is a criminal offence, the burden rests on the Crown to prove the requisite mens rea.

Where an offence is a regulatory offence and is silent as to the requisite fault element, there is a presumption that it is a strict liability offence. In this case, the Crown is required to prove only the actus reus BARD and negligence is inferred from this in the absence of proof on the part of the accused (on a balance of probabilities) that he or she took reasonable care to avoid the prohibited consequence. (Sault Ste. Marie)

Not all regulatory offences are either strict or absolute liability. There is a presumption that regulatory offences are strict liability where the offence provision is silent as to mens rea. There is a further presumption that an offence is one of absolutely liability only where Parliament or the legislature makes this intention clear through either explicit language or other indications, such as subject matter or context (regulatory, minor penalty, no stigma). However, Parliament and provincial legislatures can also create a regulatory offence that requires the Crown to prove a mens rea element, either subjective or objective (e.g., knowledge, intent, reasonable foreseeability, etc.) by including language to this effect. (Sault Ste. Marie, Stasser)

Hierarchy of forms of mens rea or fault: #

1. full or subjective MR

2. objective foresight or knowledge (the accused ought to have known a consequence would follow)

3. criminal negligence (occurs only where offence is pursuant to ss. 219, 220, or 221)

4. penal negligence (criminal offence involving a departure from a standard: e.g., careless use of a firearm)

5. strict liability (Crown proves AR, accused may establish defence of due diligence or incapacity)

6. absolute liability (Crown proves AR, no fault necessary)

Subjective mens rea: #

If a criminal offence contains a specific term or phrase such as “with intent,” “wilfully,” “knowingly,” etc., this will generally exclude lower forms of mens rea. For example, a provision requiring that a prohibited consequence be committed intentionally, willfully, or on purpose will exclude knowledge, wilful blindness, or recklessness as alternate forms of mens rea. (Buzzanga; Chartrand, SCC 1994)

Where a provision requires the proof of intention or wilfulness, the Crown may prove this by establishing either:

i. direct intent: i.e., that the accused consciously or deliberately intended to bring about the prohibited consequence.

(For example, in the offence of ‘wilfully promoting hatred’: a person intends to communicate and also directly/explicitly intends for his communication to promote hatred)

ii. indirect intent: i.e., that the accused intended to do one thing but subjectively foresaw that a prohibited consequence was certain or substantially certain to follow from it.1

(For example, communicating something that is substantially certain to promote hatred – here a person may intend only to communicate something satirical, but where he also foresees that it is substantially certain to promote hatred as well, he is deemed to have intended to promote hatred too, even though his immediate intention might only have been to communicate a satirical message.)

In both cases the accused will be found to have intended the prohibited consequence. (Buzzanga)

Where an offence requires that something be done ‘for the purpose’ of achieving a prohibited result, the Crown need only prove that a person acted intentionally or deliberately in effecting that result. The Crown need not prove that the person also desired it. Conversely, where a person carries out a certain act deliberately but does not desire that it be done (killing, assault, etc.), she does not thereby negate the intentional character of her act (but she may rely on the defence of duress). (Hibbert)

Recklessness is a subjective form of mens rea in which a person is aware of a risk (of a prohibited result) but decides to take it. (Sansregret)

Wilful blindness is a form of mens rea in which a person becomes aware of the need for some inquiry but declines to make it (or is “deliberately ignorant”). (Sansregret, Duong, Briscoe)

WB requires a strong suspicion of a prohibited consequence, combined with a deliberate choice not to inquire so as to avoid being fixed with knowledge. The fault lies not in failing to inquire but choosing not to when a strong suspicion is aroused. (Briscoe)

Wherever knowledge is an element of the fault component for an offence, wilful blindness may substitute. (Briscoe)

If wilful blindness substitutes for the knowledge element in a charge of murder it requires – for either the principal or the party – not just a ‘strong suspicion of a prohibited consequence’ but awareness that death is likely. (Roach, Sankoff and Manning)

Whether a person was reckless or wilfully blind does not involve a consideration of the perspective of the reasonable person. Where an offence requires proof of recklessness or wilful blindness, the question for the trier of fact is not whether the accused ought to have been aware of a risk, or ought to have made an inquiry, but rather, whether she was personally aware of a risk or deliberately ignorant of the need for an inquiry. (Sansregret, Briscoe)

Objective forms of mens rea: #

Objective forms of mens rea are offences in which one or another part of the fault element of the offence is assessed in terms of the reasonable person.

The form or level of objective fault may vary depending on the offence. Some offences require only ‘objective knowledge,’ or the reasonable person’s awareness of the risk of a prohibited consequence. Other offences employ the concept of negligence and are assessed in terms of the accused’s departure from the standard of care of the reasonable person.

Criminal offences that involve the concept of negligence take two forms. “Criminal negligence” refers exclusively to the offences set out in sections 219, 220, and 221. These hold a person criminally responsible for either their awareness of or failure to be aware of the risk arising from conduct amounting to a marked and substantial departure from the standard of care the reasonable person and their failure to avoid it where the reasonable person in their circumstances would have been able to.

By contrast, all other criminal offences that involve negligence (i.e., the departure from a standard of care) are referred to as “penal negligence” offences. A person is held responsible under these offences for the same awareness or failure to be aware of a risk arising from their conduct as in “criminal negligence” offences, but here the standard is simply conduct amounting to a marked departure from that of the reasonable person.

For all criminal offences involving objective forms of fault, the onus remains on the Crown to prove mens rea.

By contrast, the Supreme Court in Wholesale Travel held that the minimum level of fault required in order for a regulatory offence carrying a prison sentence to be consistent with section 7 of the Charter is negligence simplicitor. (Thus, a provincial offence leading to jail can rest on strict liability.)

In a strict liability offence, negligence may be inferred from the actus reus in the absence of proof that the accused acted with reasonable care (due diligence). The Crown need not prove a fault element – it suffices for the negligence to be inferred from the actus reus with the persuasive burden shifting to the accused to prove a lack of negligence. (Wholesale Travel)

In criminal offences involving an objective form of fault, courts apply a “modified objective test,” which asks whether the risk raised by the conduct at issue would have been foreseeable to the reasonable person in the same circumstances of the accused – but without the reasonable person sharing the personal characteristics of the accused such as age, education, and experience. (Creighton)

i. Objective foresight or knowledge: #

Forms of objective fault are found in a variety of offences. For example, some might require that a person “knew or ought to have known” something. Some offences of objective fault entail a dual structure where part of the actus reus might require subjective (or objective) fault but the prohibited consequence requires only objective foresight of non-trivial harm. Examples of this include manslaughter, unlawful act causing bodily harm, and assault causing bodily harm.

In the case of manslaughter (by unlawful act) or unlawful act causing bodily harm (s. 269), the Crown must prove the mens rea for the unlawful act (intent for assault), along with objective foreseeability of the risk of bodily harm beyond the trivial or the transitory. (Creighton, DeSousa)

ii. Penal and criminal negligence: #

In Creighton, the Court set out a general framework for assessing the actus reus and mens rea for penal negligence offences:

Actus reus: an act or omission constituting a marked departure from the conduct of the reasonably prudent person in the circumstances.

Mens rea: (a) awareness of the risk arising from conduct amounting to a marked departure from that of the reasonable person in the circumstances; or

(b) the failure to be aware of this risk where it was objectively foreseeable (which may be inferred from the actus reus absent evidence of incapacity or a reasonable mistake of fact).

To be clear, where the actus reus has been proved (i.e., conduct amounting to a marked departure), the accused bears an evidentiary but not a persuasive burden with respect to the defences of incapacity and mistake of fact. The accused can thus raise a doubt about whether the reasonable person in her circumstances would have been aware of the risk by virtue of adducing some evidence of:

i. incapacity (i.e., the accused suffered some physical or mental incapacity that would have prevented the reasonable person, suffering the same condition, from appreciating the risk posed by the conduct at issue, or abiding by a reasonable standard of care); or

ii. an honest and reasonable belief in a mistaken fact. (Creighton, Beatty)

For either defence, once the evidentiary burden is met (some evidence), the persuasive burden remains on the Crown to prove BARD that incapacity or mistake of fact do not apply (i.e., there is no reasonable possibility that they do apply). (See note on mistake of fact below.)

The Supreme Court in R v JF confirmed that a similar framework applies to criminal negligence (s. 219):

Actus reus: an act or omission “showing wanton and reckless disregard” for the lives or safety of others, which is assessed on the basis of whether the conduct in question constituted a marked and substantial departure from the standard of care of the reasonable person in the circumstances [+ causing either bodily harm or death, depending on whether person is charged under section 220 or 221].

Mens rea: (a) awareness of the risk to lives or safety of others arising from conduct amounting to a marked and substantial departure from that of the reasonable person in the circumstances; or

(b) the failure to be aware of this risk where it was objectively foreseeable (which may be inferred from the actus reus absent evidence of incapacity or a reasonable mistake of fact).

The defences to criminal negligence would operate in the same fashion as those for penal negligence offences, as noted above.

The Supreme Court’s decision in Beatty entails a slight exception to this framework for negligence-based criminal offences in that it holds that the actus reus for dangerous driving in s. 249 is driving that is “objectively dangerous, having regard to all the circumstances.” The SCC in Roy held that to establish the mens rea under 249, the Crown must prove that the reasonable person in the circumstances would have foreseen the risk arising from the driving and taken steps to avoid it, or that the accused’s failure to foresee the risk and take steps to avoid it constituted a marked departure from the standard of care of the reasonable driver (absent evidence of incapacity or a reasonable mistake of fact).

In a series of cases dealing with penal negligence, the Supreme Court has held that given the criminal nature of these offences, section 7 of the Charter requires at least proof on the part of the Crown of negligence to the standard of a marked departure. Put otherwise, the minimal constitutional standard of negligence for a criminal offence is proof of conduct amounting to a marked departure from the standard of care of the reasonable person—and either the accused’s awareness of this or their failure to be aware in circumstances in which the reasonable person would have been aware. (Creighton, Hundal, Beatty)

Strict Liability: #

Where a regulatory offence is silent as to mens rea, there is a presumption that it is a strict liability offence. (Sault Ste-Marie)

In a strict liability offence, the Crown must prove only the actus reus beyond a reasonable doubt. The accused may raise a doubt about the actus reus by adducing evidence that the act was involuntary (or by raising a doubt about whether it was voluntary). (S.S. Marie)

In a strict liability offence, once the Crown has proved the actus reus, the accused is entitled to an acquittal if he can establish, on a balance of probabilities, that he:

i. took all reasonable care to avoid the event (due diligence); or

ii. reasonably believed in a mistaken set of facts. (S.S. Marie, Wholesale Travel)

In assessing reasonable care or reasonable mistake of fact here, “the Court considers circumstances that the reasonable person would have seen, not the circumstances that the accused actually perceived.” (K. Roach, Criminal Law, 5^th^ edition.)

Placing the accused in this reverse onus violates 11(d) of the Charter but is justified under s. 1 on the basis of the importance of strict liability offences as a means of advancing public policy objectives and the difficulty of requiring the Crown to prove negligence in cases of this nature. (Wholesale Travel)

Absolute Liability: #

In an absolute liability offence, the Crown need only prove the actus reus (beyond a reasonable doubt). The accused may raise a doubt whether the actus reus has been proved and/or was carried out voluntarily.

An offence is presumed not to involve absolute liability unless Parliament or the legislature makes this intention clear through explicit language, or if the subject matter or context implies this. (Levis, Sault Ste. Marie)

An absolute liability offence that gives rise to the possibility of imprisonment or other deprivations of liberty (probation) violates section 7 of the Charter and is not justified under section 1. (B.C. Motor Vehicle Reference)

An absolute liability offence may be defended by seeking to raise a doubt about whether the actus reus was committed voluntarily due to automatism, mental disorder, extreme intoxication, or necessity. The defence of mistake of fact (even if reasonable) is not available. (Hickey, OCA 1976; K. Roach, Criminal Law, 5^th^ edition.)

Constitutional Considerations: #

The Supreme Court has held that certain offences carry a “special stigma” – possibly involving the penalty attached to them, but not necessarily – and that the principles of fundamental justice require proof of a level of fault commensurate with this stigma. A conviction for theft would require “proof of some dishonesty,” for murder, proof of “subjective foresight” of death. (Vaillancourt, Martineau)

A conviction for murder cannot be based on proof of an objective form of fault, i.e., what the accused “ought to have known” or “ought to have foreseen.” (Martineau)

In the case of ‘war crimes’ or ‘crimes against humanity,’ fundamental justice requires more than the mens rea for the various crimes committed as part of these offences (murder, kidnapping, etc.). It also requires additional subjective mens rea of the fact that the actions in question are carried out in circumstances which bring the offence within the definition of war crimes or crimes against humanity. (Finta)

Note on the defence of ‘mistake of fact’ #

Mistake of fact is a defence in the sense that it may form the basis of a reasonable doubt about mens rea rather than serving as a justification or excuse where elements of the offence have been established.

In the case of full or subjective mens rea offences, an honest but mistaken belief in a fact may raise a doubt about mens rea even if the belief is not reasonable.

In the case of subjective mens rea offences, “the existence or non-existence of reasonable grounds” for a mistaken belief “is merely relevant evidence to be weighed” by the trier of fact in assessing whether the belief was honestly held. (Rees)

In the context of sexual assault (a subjective mens rea offence), the operation of this rule has been qualified by section 273.2(b) which states that an accused may not rely on a mistaken belief in consent unless he or she can establish that they took “reasonable steps, in the circumstances known to the accused at the time, to ascertain that the complainant was consenting”.

In the case of negligence-based and objective mens rea offences (objective foresight), mistake of fact is available as a defence but subject to the requirement that the mistaken fact be both honestly held and reasonable (i.e., in the eyes of the reasonable person).

Evidentiary and Persuasive Burdens in Mistake of Fact: #

For full subjective and objective fault criminal offences: #

The accused bears an evidentiary but not a persuasive burden to rely on this defence. The test for an evidentiary burden in the case of defences generally is that the accused must simply raise some evidence for each element of the defence on which a properly instructed jury acting reasonably could acquit if it believed the evidence to be true (or in this case, if it believed the mistake was honestly held [and also, for objective fault offences, reasonable]).

Once the evidentiary burden is met (i.e., ‘some evidence for each element’), the Crown must prove BARD that the mistake was either not honestly held or, in the context of an objective fault offence, not honestly held or not reasonable or both. (i.e., that there is no reasonable possibility that…)

For strict liability: #

The Crown bears a burden to prove only the actus reus BARD, and then both the evidentiary and persuasive burdens shift to the accused to prove, on a balance of probabilities, that she took reasonable steps to avoid the conduct at issue or acted on the basis of a belief, honestly and reasonably held, amounting to a mistake of fact.


  1. Note that in some cases the Code or statute may provide otherwise: e.g., section 429(1) of the Code states that in Part XI of the Code, a person may do something ‘wilfully’ where she acts with knowledge that a prohibited consequence is only probable. ↩︎

© Robert Diab, TRU Law, 2022