Elements of an offence: the guilty mind and causation

Ms. Liu starts the fourth class by dropping a heavy textbook on the floor. Several students jump. Did she assault the room? Nobody thinks so, because she meant only to make a noise. Now, she says, suppose she had thrown the book at Marco and missed. Suppose she had thrown it at the wall knowing he was standing beside it. Suppose she had tossed it carelessly over her shoulder without looking. The act could be identical in each case, but the law treats the four people very differently, because criminal law is concerned with what was in the actor's mind. That mental element is called mens rea, the guilty mind. This lesson explains the levels of mental fault, how officers gather evidence of what someone was thinking, and the related question of causation: when the accused's conduct legally caused a result such as death.

Why the guilty mind matters

The requirement of a guilty mind reflects a basic idea of justice: people should be punished for harm they chose to cause or risked causing, not for accidents. A driver who hits a child who darts into the road, despite driving carefully, has caused a terrible harm but has done nothing wrong. Requiring a guilty mind also makes the law fair to the accused in another way: it lets people avoid criminal liability by choosing to obey the law. The Supreme Court of Canada has given this idea constitutional force. In Re B.C. Motor Vehicle Act (1985), it held that an offence with no fault requirement at all cannot carry a possible jail term, because imprisoning a morally innocent person violates section 7 of the Charter. In R. v. Vaillancourt (1987) and R. v. Martineau (1990), it held that a few offences carry such stigma, murder above all, that the Charter requires subjective fault, meaning the accused personally knew of or intended the relevant consequences.

Mens rea is not the same as motive. Motive is the reason a person acted: greed, jealousy, revenge, desperation. Intent is the mental state with which the person acted. A woman who steals bread to feed her children has a sympathetic motive, but she intends to take bread that is not hers, and that is theft. Motive is not an element of most offences and need not be proved, though it is often powerful evidence, because people rarely act without a reason. In R. v. Lewis (1979), the Supreme Court said motive is always relevant and evidence of motive is admissible, and its absence may be important in favour of the accused, but it is not part of the offence.

Levels of fault in Canadian criminal law

Canadian law distinguishes subjective fault, which looks at what was actually in the accused's mind, from objective fault, which compares the accused's conduct with that of a reasonable person. The subjective forms, from most to least culpable, are intent, knowledge and recklessness. Intent means the person meant to bring about the prohibited act or consequence, or knew it was certain to follow. Knowledge means awareness that a circumstance exists, such as that property is stolen, and it can be proved by wilful blindness: in R. v. Sansregret (1985) and R. v. Briscoe (2010), the Supreme Court held that a person who suspects a fact but deliberately avoids confirming it, because he does not want to know, is treated as knowing it. Recklessness means the person was aware of a risk that the prohibited consequence would occur or circumstance existed, and went ahead anyway.

Objective fault takes two forms. Criminal negligence, under section 219, is conduct showing wanton or reckless disregard for the lives or safety of other persons, and the Supreme Court has held that it requires a marked and substantial departure from the conduct of a reasonably prudent person. Penal negligence, which applies to offences such as dangerous driving and failing to provide necessaries, requires a marked departure from the standard of care a reasonable person would exercise in the circumstances; in R. v. Hundal (1993), R. v. Beatty (2008) and R. v. Roy (2012), the Court explained that a momentary lapse of attention, even with tragic results, is not enough. Finally, regulatory offences, the provincial offences of lesson 2, have their own categories, set out in R. v. Sault Ste. Marie (1978). Most are strict liability: the prosecution need prove only the act, and the defendant avoids conviction by proving due diligence, meaning that he or she took all reasonable care. A few are absolute liability, where no fault is required and no due diligence defence is available, but these cannot carry jail.

Proving what someone was thinking

Nobody can see inside another person's mind, so the guilty mind is almost always proved by inference from what the person said and did. The law allows a common sense inference that a sane and sober person intends the natural and probable consequences of his or her acts. A man who swings a baseball bat at another person's head can be inferred to have intended at least bodily harm. But the inference is not automatic, and the judge or jury must consider everything that might point the other way, such as intoxication, panic or an honest mistake. Canadian appeal courts have warned that the common sense inference must never be presented to a jury as a presumption the accused must disprove, especially where there is evidence of intoxication.

That is why the officer's notes matter so much. Statements made at the scene are often the best evidence of intent: a man who says I told him I would make him pay before he hit him has supplied his own mens rea. So is preparation, such as bringing a weapon or buying gloves; concealment, such as wiping fingerprints or lying about where one was; the number and location of blows; threats before the event; the relationship between the parties; and what the person did afterward, such as calling for help or running away. Good notes record exact words in quotation marks, the sequence of events and observations of the person's condition, such as whether he appeared sober, coherent and calm. Ms. Liu says that more cases are lost for want of evidence about the mind than for want of evidence about the act.

Mistakes of fact and mistakes of law

An honest mistake of fact can mean the accused lacked the required guilty mind. A woman who takes an identical umbrella from a restaurant rack, honestly believing it is hers, has not stolen it, because she did not intend to take property belonging to another. For offences requiring subjective fault, the mistake need only be honest, not reasonable, though an unreasonable claim is less likely to be believed. For offences of negligence, the mistake must also be reasonable. Special statutory rules apply to sexual assault, where section 273.2 says a belief in consent is no defence if the accused did not take reasonable steps to ascertain that the complainant was consenting; this is covered in lesson 8.

A mistake of law is different. Section 19 of the Criminal Code says ignorance of the law by a person who commits an offence is not an excuse. Everyone is presumed to know the criminal law, because a system in which people could escape liability by claiming they did not know the rules could not work. There are narrow exceptions. In R. v. Jorgensen (1995) and Lévis (City) v. Tétreault (2006), the Supreme Court recognized officially induced error: a person who reasonably relies on erroneous legal advice from an official responsible for the law in question, such as a licensing office, may be excused. For officers, this has a practical side: officers must be careful when they tell members of the public what the law allows, because their words can later be relied on.

Causation: did the conduct cause the result?

For result crimes such as homicide and assault causing bodily harm, the prosecution must prove that the accused's conduct caused the prohibited consequence. Causation has two parts. Factual causation asks whether the result would have happened but for the conduct. Legal causation asks whether the accused should be held legally responsible for the result, which depends on how direct the connection was and whether something else intervened. In R. v. Smithers (1978), the Supreme Court held that the conduct need only be a contributing cause beyond the de minimis range, meaning more than trivial, and in R. v. Nette (2001) it rephrased the test as whether the accused's conduct was a significant contributing cause of the result. The conduct need not be the only cause or the main cause. In R. v. Maybin (2012), the Court held that an intervening act by another person does not necessarily break the chain: two brothers who beat a man unconscious in a bar were responsible for his death even though a bouncer delivered the final blow, because further violence was a reasonably foreseeable result of their attack.

Two further rules matter often. The first is the thin skull rule, also called the eggshell skull rule: you take your victim as you find him. If a man punches someone who, unknown to him, has a fragile skull or a heart condition and the victim dies, the man is responsible for the death even though a healthy person would have survived. Smithers itself applied this rule to a teenager who kicked another boy in the stomach after a hockey game; the boy died because he vomited and inhaled the vomit, a rare reaction. The second is that poor medical treatment of an injury rarely breaks the chain of causation. Section 225 of the Criminal Code says a person who causes a bodily injury that is dangerous in itself is responsible for the resulting death even though the immediate cause was improper treatment applied in good faith. For investigators, these rules mean that the full medical picture, from the first injury to the cause of death certified by the pathologist, must be documented.

The code below applies the fault hierarchy to a set of situations from Port Ardent files, showing how the proved mental state compares with what each offence requires. Marco says it helps him see why the same act can lead to very different charges.

# Does the proved fault meet what the charge requires? (simplified)
subjective = ["intent", "knowledge", "recklessness"]          # most to least culpable
objective = ["marked and substantial departure", "marked departure"]
def meets(required, proved):
    if required in subjective:
        return proved in subjective and subjective.index(proved) <= subjective.index(required)
    if required in objective:
        # proof of any subjective fault, or of a more serious departure, also meets an objective standard
        return proved in subjective or objective.index(proved) <= objective.index(required)
    return True  # strict liability: the act is enough unless due diligence is shown
cases = [("assault", "intent", "intent"), ("mischief", "recklessness", "intent"),
         ("possession of stolen property", "knowledge", "recklessness"),
         ("dangerous driving", "marked departure", "marked and substantial departure"),
         ("criminal negligence causing bodily harm", "marked and substantial departure", "marked departure"),
         ("speeding", "strict liability", "none")]
for charge, required, proved in cases:
    print(f"{charge:40s} requires {required:32s} proved {proved:32s} -> {'met' if meets(required, proved) else 'NOT met'}")

assault                                  requires intent                           proved intent                           -> met
mischief                                 requires recklessness                     proved intent                           -> met
possession of stolen property            requires knowledge                        proved recklessness                     -> NOT met
dangerous driving                        requires marked departure                 proved marked and substantial departure -> met
criminal negligence causing bodily harm  requires marked and substantial departure proved marked departure                 -> NOT met
speeding                                 requires strict liability                 proved none                             -> met

The output shows the logic the courts apply. Proof of a higher level of fault always satisfies a lower requirement, but never the reverse. Recklessness about whether property was stolen is not enough for a charge that requires knowledge, unless the evidence rises to wilful blindness, and a marked departure does not prove criminal negligence, which requires a marked and substantial departure. Getting the mental element right is often the difference between two charges, which is why the next lessons keep returning to it.