Chapter 1 - Actus Reus
03 October 2025 19:26
Definition
Actus reus refers to the external elements of an offence: the conduct, circumstances, and
consequences required by the offence definition. These must be proved by the prosecution
beyond reasonable doubt.
Conduct, Circumstances and Consequences
• Conduct – the act or omission itself (e.g. driving, hitting).
• Circumstances – the surrounding facts required by the offence (e.g. lack of consent in
sexual offences).
• Consequences – the result that must follow from the conduct (e.g. death in homicide).
Not all offences require all three; some are conduct crimes (e.g. drink driving), others
are result crimes (e.g. murder).
Voluntary Acts
Liability normally requires a voluntary act. Reflexes, convulsions, or actions done while
unconscious do not count as voluntary acts. Involuntary movement cannot form actus reus
unless the defendant was responsible for becoming incapacitated (e.g. voluntary
intoxication).
Omissions
Generally, there is no liability for failing to act, unless a legal duty to act exists. Duties arise
through:
• Statutory duties – e.g. failing to provide a specimen under road traffic law.
• Contractual duties – e.g. failing to perform a job duty leading to harm.
• Assumption of responsibility – voluntarily caring for another and failing to act.
• Special relationships – such as parent–child.
• Creation of a dangerous situation – if D creates a risk, they must take steps to avert it.
If a duty exists and D fails to act voluntarily, the omission can form part of the actus
reus.
Causation
For result crimes, the prosecution must prove that D’s conduct caused the prohibited
consequence. Two stages are required:
Factual Causation
• The “but for” test: would the result have occurred but for D’s conduct?
• If yes, D is not the factual cause.
Legal Causation
• D’s act must be a substantial and operating cause of the result.
• The act need not be the sole or main cause but must make a significant contribution.
• A novus actus interveniens (new intervening act) may break the chain of causation if it
is independent and potent enough to render the original act insignificant.
Intervening Acts
• Third-party acts – only break the chain if free, deliberate, informed, and independent
of D’s act.
• Victim’s acts – will not break the chain if the reaction is reasonably foreseeable.
• Medical treatment – usually does not break the chain unless grossly negligent and
Criminal Law Page 1
, • Medical treatment – usually does not break the chain unless grossly negligent and
overwhelming.
• Natural events – can break the chain if unforeseeable.
Thin Skull Rule
D must take the victim as they find them. Pre-existing vulnerabilities do not break the chain
and D remains liable even if the result is more serious due to the victim’s condition
Criminal Law Page 2
,Chapter 2 - Mens Rea
03 October 2025 21:35
Definition
Mens rea refers to the mental element of the offence. Different offences require different mental
states. It must usually coincide with the actus reus to establish liability.
Intention
Intention is the highest level of mens rea.
Two forms are recognised:
Direct Intention
D acts with the aim or purpose of bringing about the prohibited consequence or circumstance.
Oblique Intention
D foresees the consequence as a virtual certainty, and appreciates this, even if it was not their
purpose. This applies mainly to serious offences (e.g. murder) where foresight is evidence of
intention.
Recklessness
Recklessness involves foreseeing a risk and unreasonably taking it.
It is subjective: D must actually foresee the risk, and it must be unreasonable to take it in the
circumstances known to them.
Negligence
Negligence is rare in criminal law. It involves failing to meet the standard of a reasonable person. It
is used in certain statutory offences and gross negligence manslaughter, where the failure must be
gross.
Knowledge and Belief
Some offences require proof that D knew or believed certain facts (e.g. knowing property is stolen).
• Knowledge means being sure of a fact.
• Belief means thinking it is true, even if not absolutely certain.
Mere suspicion is insufficient unless the offence expressly criminalises suspicion.
Transferred Mens Rea
If D has the mens rea for an offence against one target but the actus reus affects another, liability
can transfer if both the actus reus and mens rea relate to the same type of offence.
It does not apply where the intended and actual offences are different in nature.
Case: R v Latimer (1886)
• The defendant aimed a blow with a belt at a man during an argument.
• The belt struck the intended man but also hit a woman nearby, injuring her.
• His intention to harm the man was transferred to the woman.
• Held: Latimer was guilty of assault on the woman because the mens rea transferred from the
intended victim to the actual victim
Coincidence of Actus Reus and Mens Rea
The mental element must exist at the same time as the actus reus.
• A continuing act can allow coincidence (e.g. a single continuous unlawful act with mens rea
arising during it).
• A series of acts forming one transaction can also satisfy coincidence if mens rea is present at
Criminal Law Page 3
, • A series of acts forming one transaction can also satisfy coincidence if mens rea is present at
some point during the sequence.
Strict Liability
Some offences dispense with mens rea for all or some elements.
• Usually regulatory offences.
• Parliament’s intention is key; if silence, courts presume mens rea is required unless clearly
displaced.
• For strict liability offences, actus reus alone is sufficient for conviction.
Defences like mistake of fact generally do not apply unless expressly allowed.
Criminal Law Page 4
03 October 2025 19:26
Definition
Actus reus refers to the external elements of an offence: the conduct, circumstances, and
consequences required by the offence definition. These must be proved by the prosecution
beyond reasonable doubt.
Conduct, Circumstances and Consequences
• Conduct – the act or omission itself (e.g. driving, hitting).
• Circumstances – the surrounding facts required by the offence (e.g. lack of consent in
sexual offences).
• Consequences – the result that must follow from the conduct (e.g. death in homicide).
Not all offences require all three; some are conduct crimes (e.g. drink driving), others
are result crimes (e.g. murder).
Voluntary Acts
Liability normally requires a voluntary act. Reflexes, convulsions, or actions done while
unconscious do not count as voluntary acts. Involuntary movement cannot form actus reus
unless the defendant was responsible for becoming incapacitated (e.g. voluntary
intoxication).
Omissions
Generally, there is no liability for failing to act, unless a legal duty to act exists. Duties arise
through:
• Statutory duties – e.g. failing to provide a specimen under road traffic law.
• Contractual duties – e.g. failing to perform a job duty leading to harm.
• Assumption of responsibility – voluntarily caring for another and failing to act.
• Special relationships – such as parent–child.
• Creation of a dangerous situation – if D creates a risk, they must take steps to avert it.
If a duty exists and D fails to act voluntarily, the omission can form part of the actus
reus.
Causation
For result crimes, the prosecution must prove that D’s conduct caused the prohibited
consequence. Two stages are required:
Factual Causation
• The “but for” test: would the result have occurred but for D’s conduct?
• If yes, D is not the factual cause.
Legal Causation
• D’s act must be a substantial and operating cause of the result.
• The act need not be the sole or main cause but must make a significant contribution.
• A novus actus interveniens (new intervening act) may break the chain of causation if it
is independent and potent enough to render the original act insignificant.
Intervening Acts
• Third-party acts – only break the chain if free, deliberate, informed, and independent
of D’s act.
• Victim’s acts – will not break the chain if the reaction is reasonably foreseeable.
• Medical treatment – usually does not break the chain unless grossly negligent and
Criminal Law Page 1
, • Medical treatment – usually does not break the chain unless grossly negligent and
overwhelming.
• Natural events – can break the chain if unforeseeable.
Thin Skull Rule
D must take the victim as they find them. Pre-existing vulnerabilities do not break the chain
and D remains liable even if the result is more serious due to the victim’s condition
Criminal Law Page 2
,Chapter 2 - Mens Rea
03 October 2025 21:35
Definition
Mens rea refers to the mental element of the offence. Different offences require different mental
states. It must usually coincide with the actus reus to establish liability.
Intention
Intention is the highest level of mens rea.
Two forms are recognised:
Direct Intention
D acts with the aim or purpose of bringing about the prohibited consequence or circumstance.
Oblique Intention
D foresees the consequence as a virtual certainty, and appreciates this, even if it was not their
purpose. This applies mainly to serious offences (e.g. murder) where foresight is evidence of
intention.
Recklessness
Recklessness involves foreseeing a risk and unreasonably taking it.
It is subjective: D must actually foresee the risk, and it must be unreasonable to take it in the
circumstances known to them.
Negligence
Negligence is rare in criminal law. It involves failing to meet the standard of a reasonable person. It
is used in certain statutory offences and gross negligence manslaughter, where the failure must be
gross.
Knowledge and Belief
Some offences require proof that D knew or believed certain facts (e.g. knowing property is stolen).
• Knowledge means being sure of a fact.
• Belief means thinking it is true, even if not absolutely certain.
Mere suspicion is insufficient unless the offence expressly criminalises suspicion.
Transferred Mens Rea
If D has the mens rea for an offence against one target but the actus reus affects another, liability
can transfer if both the actus reus and mens rea relate to the same type of offence.
It does not apply where the intended and actual offences are different in nature.
Case: R v Latimer (1886)
• The defendant aimed a blow with a belt at a man during an argument.
• The belt struck the intended man but also hit a woman nearby, injuring her.
• His intention to harm the man was transferred to the woman.
• Held: Latimer was guilty of assault on the woman because the mens rea transferred from the
intended victim to the actual victim
Coincidence of Actus Reus and Mens Rea
The mental element must exist at the same time as the actus reus.
• A continuing act can allow coincidence (e.g. a single continuous unlawful act with mens rea
arising during it).
• A series of acts forming one transaction can also satisfy coincidence if mens rea is present at
Criminal Law Page 3
, • A series of acts forming one transaction can also satisfy coincidence if mens rea is present at
some point during the sequence.
Strict Liability
Some offences dispense with mens rea for all or some elements.
• Usually regulatory offences.
• Parliament’s intention is key; if silence, courts presume mens rea is required unless clearly
displaced.
• For strict liability offences, actus reus alone is sufficient for conviction.
Defences like mistake of fact generally do not apply unless expressly allowed.
Criminal Law Page 4
