CHAPTER 3 – Actus Reus: Causation
Causation in Criminal Law
There must be causal connection between accused’s conduct and the consequences prohibited by the criminal law.
Crown must prove both of both elements to get conviction. (from Nette Case 2001)
o Factual Causation an inquiry about how the victim came to his or her death, in a medical, mechanical or
physical sense and with the contribution of the accused to that result
Can be decided by asking whether the prohibited consequences would not have happened “but for” the
conduct of the accused.
o Legal Causation question of whether the accused should be held responsible in law for the death
Around the fairness of holding an accused person criminally responsible.
Often can be determined by asking whether the prohibited consequences were foreseeable.
In some cases, the necessary mens rea for an offence may be recklessness as to the consequences of one’s conduct.
A reckless person foresees that his or her conduct may produce a prohibited consequence and does not care whether or not that
It is a relatively simple task for the crown to establish the necessary cause chain, where the consequences of one’s conduct are
actually foreseen – even if the accused did not intend to bring such consequences about
Objective mens rea, the foreseeability requirement in relation to causation may be satisfied on the basis of an objective test (would
the reasonable person have foreseen the consequences in question?)
Specific Rules Concerning Causation in Homicide Cases
Given the serious nature of the crimes concerned, there are special rules concerning the issue of causation in relation to
such offences as murder, manslaughter, infanticide and criminal negligence, or dangerous driving, causing death
Crown must prove that the victim was, in fact, dead after the accused inflicted injuries on him or her
Definition of death/dead = “A person is dead when an irreversible cessation of all that person’s brain functions has occurred”
o in light of medical advances that render it possible to sustain certain bodily functions on an indefinite basis.
o Until 1999, one of the most ancient rules of causation was preserved by Section 227 of the Criminal Code: namely,
that the death of a victim must occur within one year and a day of the last events “by means of which caused or
contributed to the cause of death”
SC repealed section 227 in 1999
Acceleration of Death = s226 is criminally responsible even if injury only accelerated death from other causes.
o Must have intent If the intent of the doctor is to relieve pain and suffering and not kill the patient, then the fact
that death is incidentally hastened by the administration of a pain-killing drug does not render the physician
o Active Euthanasia = Deliberately taking steps to terminate the life of another person
Is a crime. (Eg mercy killing, injective of lethal drug )
o Passive Euthanasia = Withdrawing treatment and permitting a patient to die from a disease
Is not considered to be a crime (everyone has right to refuse treatment)
o Assisted Suicide = s241b – indictable offence to aid a person to commit suicide
Purpose is the protection of vulnerable who might be induced in moments of weakness to commit suicide
SCC- prohibition of assisted suicide section 241 of the Criminal Code is not invalid in light of the Charter
Liability of the accused where there is more than One Cause of Death
An extraordinary physical defect may constitute one of the effective causes of death, but the accused will still be convicted
if the wound inflicted by him or her made a significant contribution to the victim’s ultimate demise.
o “Thin-skull” rule = “one takes one’s victims as one finds them.”
Smithers case (1977) - Accused kicked Cobby (deceased) in the stomach and cobby fell to floor, vomited. He died due to
foreign materials in vomit. Accused argued kick did not cause the vomit.
o Smithers test of causation = accused’s conduct must be a contributing cause, “outside the de minimis range” =
must have had more than a minimal impact.
Nette case (2001), old lady lived alone, robbers tied her around neck and abandons, after they left, she fell off bed and died
o SCC reaffirmed the validity of the “Smithers test” for all forms of homicide.
o Re-worded test so easier to understand = “Significant contributing cause” rather than using expressions phrased
in the negative such as not a trivial cause or not insignificant The Special Test of Causation for First Degree Murder
To be convicted on first degree muster = Crown must prove that a murder was planned and deliberate
o Exceptions: automatically 1 degree when death occurs while committing these offences:
Hijacking an aircraft, sexual assault, sexual assault with weapon/threats third party/causing bodily harm, aggravated
sexual assault, kidnapping, or hostage taking, killing peace officer or prison guard
Harbottle case(1993) = friend strangle, Harbottle held legs, together killed the victim
o made more restrictive test of causation for first-degree murder accused’s action must form a
substantial and integral part of the killing of the victim
Intervening Act = Occurs between the defendant’s original wounding of the victim and the latter’s subsequent death
If IA breaks chain of causation, then accused will not be convicted of culpable homicide
o A poisons X but, before it has any effect, X is slashed on throat by B. A is only guilty for attempted
(MacKay) A and B independently inflicts wounds on X, not fatal. C comes and give CPR to X, but vomits and X
dies of asphyxiation. In this situation, both A and B are guilty of culpable homicide, because initial injury were
significant contributing cause of victim’s death.
o Consequences of A&B’s action continued up to the time of death, even without interruption, would
have significant causal effect to victim’s death.
Intervening Act (nature) that would not have caused death, but for accused’s assault = still guilty
o eg beat up and left under tree unconscious, then tree branch falls and kills
o can victim’s death from external event be viewed as a ‘natural consequences’ of the accused’s action?
o Crown must establish is that the victim's death from the IA was foreseeable by the accused at the time
he or she wounded the victim.
Improper medical treatment = An accused person will be excused from criminal responsibility only in the very
unusual situation where the impact of the improper medical treatment is so overwhelming that the court may
legitimately conclude that the original wound inflicted by the accused should be considered no more than “part
of the history.”
o Eg case of Jordan (1956), murder someone. At hospital, but few days later wounds ‘mainly healed at time of death’, doctor’s
bad treatment caused infection and killed victim. Chain is broken.
o S225 – if improper medical treatment was applied in good faith, will generally not sever the chain of causation.
Victim’s refusal of life-saving treatment does not break the chain of causation.
o S224 - accused does not have an automatic defence to a murder or manslaughter charge just because
death "might have been prevented by resorting to proper means."
Causing Death by Acting on the Victim’s Mind
o Section 222 (c) culpable homicide when causing a human to cause his own death, by threats/fear of
Eg A threatens to assault B with no route of escape, B is terrified and jumps off a building, A is
guilty for CH.
o Section 228 = No person commits culpable homicide where he causes the death of a human being
a. By any influence on the mind alone
b. By any disorder or disease resulting from influence on the mind alone, ** except causes death
to child/sick person by WILLFULLY frightening him
Powder (1981) A breaks in, scares B, struggle and B dies from ‘fear and emotional stress’,
physical attack did not contribute to death, thus victim died of ‘influence on mind alone’
Rusland (1992) A attacks B, B dies due to stress in situation and had previous hear
problems, however A actually knew about dangerous health condition, thus he ‘wilfully
frightened him to death’ guilty CHAPTER 4 – Subjective Mens Rea
Mensa rea = all mental elements (except for voluntariness) that Crown must prove, beyond a reasonable doubt, in order to obtain a
conviction of a criminal offence
o Important because it prevent the conviction of the morally innocent = those who do not understand or intend the
consequences of their acts”. (eg children under 12 or mentally insane)
Mens rea is not one mental state: it is a sum or combination of mental states
Subjective vs Objective Mens Rea
Subjective mens rea = what was actually going on inside the accused’s head
o Basic forms: Intentions and knowledge, recklessness and wilful blindness
o Cannot convict an accuse of a criminal offence unless:
1. Deliberately intended to bring about the consequences prohibited by law
2. Subjectively realized that their conduct might produce such prohibited consequences and proceeded with that
conduct regardless of their actual knowledge of that risk
Objective Mens Rea = not what in accused’s head, but what should have been there, had the accused proceeded reasonably
o A reasonable person in the same circumstances, would have realize the conduct would produce a prohibited consequences,
and would have taken action to avoid doing so
More serious crime more likely to require proof of subjective mens rea.
o Subjective – more culpable – b/c they deliberately chose to do something
o Objective – accused may not even be aware of the risk they are creating (although a reasonable person would have)
Intent and Knowledge
Many criminal offence require the proof of mens rea in form of an “INTENDED” consequences or actual “KNOWLEDGE” of particular
o Eg s265 Assault = “intentionally applies force”
o Eg s155 Incest = “knowing partner to be within a blood relationship”
o **Almost all offence requires intention, but not all requires knowledge. Knowledge may be additional mens rea requirement
beyond intent. It will be indicated in words such as “knowing”. Eg) intent to have sex with girl, but did not know was sister,
not guilty of incest, even though had intent.
Even if not explicitly stated, the courts may hold that such a requirement is implied by the language used by Parliament
o Eg Lecompte (2000) – s63 says “an unlawful assembly is a group that disturb the peace”…it does not explicitly say accused must
have knowledge it will disturb peace.
However courts ruled such knowledge is an implied element of mens rea as a requirement for the offence.
This is to avoid p