CAUSATION
Common law rules of causation apply to all result crimes, however most of the case law concerns homicide
due to the seriousness of the outcome and the greater possibility of intervening causes
Question of whether the defendant’s conduct (or omission) is a sufficient and legally operative
cause of the victim’s death at the time that it occurred (must be an unbroken ‘chain’ of causation)
Homicide- offences that involve causing the death of a person
The actus reus of both murder and manslaughter require the defendant to have caused the victim’s
death (Attorney General’s Ref (No 3 of 1994) [1998])
Murder- ‘the defendant did the act which caused the death intending to kill the victim or to
cause him at least grievous bodily harm’ (constructive crime)
There are two kinds of manslaughter- (i) voluntary manslaughter- defendant caused
death with the mens rea for murder, but qualifies for a partial defence reducing culpability
or (ii) involuntary manslaughter- defendant caused death but with a lesser degree of
fault than is required for murder
A-G's Ref (No 3 of 1994) [1998]- defendant stabbed a pregnant woman, causing the baby to
be born prematurely and later die from complications
The case highlighted that ‘what is needed in order to complete the proof of the crime is
evidence of an unbroken chain of causation between the accused’s act and the victim’s
death’
Causation is a question of fact for the jury to be decided with reference to legal principles explained
to the jury by the judge (Cheshire [1991])
‘The search for a comprehensive test of causation or set of principles has proved to be
elusive’ (Wallace [2018])- can be used in an assessment of causation
‘...considerations of policy and value judgements necessarily enter into the assessment of
causation’ (Wallace)
Key principles of causation
(1) The minimum causal contribution required of the defendant
(2) When to relieve the defendant of causal responsibility for an act or culpable omission because of a
novus actus interveniens
(3) The causal effect attributed to the defendant’s omissions (when is the defendant under a duty to
act in criminal law?)
The minimum causal contribution required of the defendant
The acceleration rule follows ‘whether the prisoner accelerated the death’ (Dyson [1908])
The prosecution must prove that the victim ‘would have lived in the sense that life would
have been significantly prolonged’ but for the defendant’s contribution (Broughton [2020])
Two-fold test establishing sufficiency of contribution (requires both elements)
, ‘But for’ (causation in fact- did the result come about because of the defendant’s conduct?)- White
[1910]
The ‘but for’ test is necessary, but not sufficient- (eg. if a defendant planted a tree by his
gate and the victim drove into it)
‘’But for’ causation ‘sets the stage for an occurrence and conduct which on a common-sense
view is regarded as instrumental in bringing about the occurrence’
Legal causation was described in Hughes [2013] as a question of common sense
Consists of three parts- significant or substantial contribution (more than de minimis),
blameworthy conduct (which causes the result) and operative (at the time of the
consequence)
However, the cases demonstrate (particularly Wallace) that the question of, despite an
intervening cause, the question is still whether the initial act was still a significant and
operative cause
In Causation in (Criminal) Law [2017], Simester argued that the question of legal causation
‘inevitably generates norm-laden conclusions’ (requires a ‘proximate’ causal relationship
‘informed by morally salient considerations’)
The defendant’s conduct must be ‘significant (or substantial)’ and more than the de minimis principle (R v
Hennigan [1971])
Does not have to be the only cause (cannot rely on others’ negligence etc.- Benge [1865])
Moral element- can the defendant’s acts ‘fairly be said to have made a significant contribution?’
(Wallace at [64] quoting Canadian case Maybin [2012])
The defendant’s conduct must be wrong and the blameworthiness of the conduct is central to causation
In Hughes, the defendant was not convicted of murder, as the manner of his driving could not be
criticised
Dalloway [1847]- ruled that, in a case of manslaughter by negligence, it must be shown that the
defendant’s negligence played a part in the victim’s death (not blameworthy, as the act would have
happened no matter what)
Hughes was approved in Taylor [2016] as the defendant being required to perform blameworthy
conduct which caused the result
When to relieve the defendant of causal responsibility for an act or culpable omission because of a novus
actus interveniens
The defendant’s conduct must also be the operative cause of the result (defendant’s conduct must still be
a significant cause of the result at the time it occurs) at the time it occurs, despite the intervening events
The chain of causation between the conduct and the result cannot be broken by subsequent actions
of events (novus actus interveniens)
Common law rules of causation apply to all result crimes, however most of the case law concerns homicide
due to the seriousness of the outcome and the greater possibility of intervening causes
Question of whether the defendant’s conduct (or omission) is a sufficient and legally operative
cause of the victim’s death at the time that it occurred (must be an unbroken ‘chain’ of causation)
Homicide- offences that involve causing the death of a person
The actus reus of both murder and manslaughter require the defendant to have caused the victim’s
death (Attorney General’s Ref (No 3 of 1994) [1998])
Murder- ‘the defendant did the act which caused the death intending to kill the victim or to
cause him at least grievous bodily harm’ (constructive crime)
There are two kinds of manslaughter- (i) voluntary manslaughter- defendant caused
death with the mens rea for murder, but qualifies for a partial defence reducing culpability
or (ii) involuntary manslaughter- defendant caused death but with a lesser degree of
fault than is required for murder
A-G's Ref (No 3 of 1994) [1998]- defendant stabbed a pregnant woman, causing the baby to
be born prematurely and later die from complications
The case highlighted that ‘what is needed in order to complete the proof of the crime is
evidence of an unbroken chain of causation between the accused’s act and the victim’s
death’
Causation is a question of fact for the jury to be decided with reference to legal principles explained
to the jury by the judge (Cheshire [1991])
‘The search for a comprehensive test of causation or set of principles has proved to be
elusive’ (Wallace [2018])- can be used in an assessment of causation
‘...considerations of policy and value judgements necessarily enter into the assessment of
causation’ (Wallace)
Key principles of causation
(1) The minimum causal contribution required of the defendant
(2) When to relieve the defendant of causal responsibility for an act or culpable omission because of a
novus actus interveniens
(3) The causal effect attributed to the defendant’s omissions (when is the defendant under a duty to
act in criminal law?)
The minimum causal contribution required of the defendant
The acceleration rule follows ‘whether the prisoner accelerated the death’ (Dyson [1908])
The prosecution must prove that the victim ‘would have lived in the sense that life would
have been significantly prolonged’ but for the defendant’s contribution (Broughton [2020])
Two-fold test establishing sufficiency of contribution (requires both elements)
, ‘But for’ (causation in fact- did the result come about because of the defendant’s conduct?)- White
[1910]
The ‘but for’ test is necessary, but not sufficient- (eg. if a defendant planted a tree by his
gate and the victim drove into it)
‘’But for’ causation ‘sets the stage for an occurrence and conduct which on a common-sense
view is regarded as instrumental in bringing about the occurrence’
Legal causation was described in Hughes [2013] as a question of common sense
Consists of three parts- significant or substantial contribution (more than de minimis),
blameworthy conduct (which causes the result) and operative (at the time of the
consequence)
However, the cases demonstrate (particularly Wallace) that the question of, despite an
intervening cause, the question is still whether the initial act was still a significant and
operative cause
In Causation in (Criminal) Law [2017], Simester argued that the question of legal causation
‘inevitably generates norm-laden conclusions’ (requires a ‘proximate’ causal relationship
‘informed by morally salient considerations’)
The defendant’s conduct must be ‘significant (or substantial)’ and more than the de minimis principle (R v
Hennigan [1971])
Does not have to be the only cause (cannot rely on others’ negligence etc.- Benge [1865])
Moral element- can the defendant’s acts ‘fairly be said to have made a significant contribution?’
(Wallace at [64] quoting Canadian case Maybin [2012])
The defendant’s conduct must be wrong and the blameworthiness of the conduct is central to causation
In Hughes, the defendant was not convicted of murder, as the manner of his driving could not be
criticised
Dalloway [1847]- ruled that, in a case of manslaughter by negligence, it must be shown that the
defendant’s negligence played a part in the victim’s death (not blameworthy, as the act would have
happened no matter what)
Hughes was approved in Taylor [2016] as the defendant being required to perform blameworthy
conduct which caused the result
When to relieve the defendant of causal responsibility for an act or culpable omission because of a novus
actus interveniens
The defendant’s conduct must also be the operative cause of the result (defendant’s conduct must still be
a significant cause of the result at the time it occurs) at the time it occurs, despite the intervening events
The chain of causation between the conduct and the result cannot be broken by subsequent actions
of events (novus actus interveniens)
