Actus Reus (OCR A-Level Law): Revision Notes
Actus Reus
Introduction
Actus reus is the physical element of a crime. It refers to the unlawful act, omission, or state of affairs that forms part of criminal liability. For most criminal offences, both the physical element (actus reus) and the mental element (mens rea) must be present and must occur at the same time.
The term actus reus covers several distinct concepts:
- What the defendant is actively doing (conduct)
- What the defendant fails to do (omissions)
- Simply being in a particular situation (state of affairs)
Understanding actus reus is fundamental to criminal liability because without this physical element, there can be no crime, regardless of the defendant's mental state.
Conduct and consequence crimes
Crimes can be categorised based on whether they focus on the defendant's conduct or on the consequences that follow from that conduct.
Conduct crimes
Some offences are complete as soon as the defendant performs the prohibited act, regardless of any consequences. An example is speeding – the offence is committed simply by driving above the speed limit. The actus reus is the act of driving at an excessive speed.
Consequence crimes
Most offences against the person are consequence crimes. This means the prosecution must prove that a specific result occurred because of the defendant's actions. For these crimes, the consequence is a required element of the actus reus.
Worked Example: Murder as a Consequence Crime
Murder is a clear example: the consequence that must be proved is the death of a human being. Without this consequence, the offence cannot be murder (though other offences may have been committed).
When the consequence is not directly and immediately caused by the defendant's action – meaning another factor is involved – the rules of causation must be applied to establish whether the defendant remains legally responsible for the outcome.
Voluntary acts and involuntariness
For an actus reus to be established, the defendant must be acting voluntarily. Criminal liability cannot be imposed for purely involuntary conduct.
The requirement of voluntariness
The law recognises that certain actions are beyond a person's control and therefore should not attract criminal liability. Involuntary actions include:
- Reflex actions
- Movements during an epileptic fit or similar medical episode
- Actions performed whilst unconscious or in an automatic state
Key cases illustrating involuntariness
R v Mitchell (1983) and R v Larsonneur (1933) established that criminal liability cannot arise from involuntary actions such as fits or reflex movements.
In Hill v Baxter (1958), Devlin J provided an important example in obiter dicta (comments made by the judge that are not binding but are persuasive). He suggested that if a driver were attacked by a swarm of bees whilst driving and consequently drove dangerously, they would not be liable for any resulting accident. This is because the driver's actions would be involuntary – they would not have true control over the vehicle.
This principle protects defendants who genuinely cannot control their actions, ensuring that criminal liability is based on voluntary conduct.
State of affairs offences
In certain circumstances, a defendant can commit an offence by simply 'being' rather than 'doing' anything. These are known as state of affairs offences.
How state of affairs offences work
The defendant does not need to perform any positive act or even intend to be in the prohibited situation. Mere presence in a particular state or possession of a particular item is sufficient for liability.
Example: offensive weapons
Section 1 of the Prevention of Crime Act 1953 makes it an offence to have an offensive weapon in a public place.
Worked Example: State of Affairs Offence
To establish the actus reus, the prosecution need only prove:
- The defendant had the weapon
- The weapon was in a public place
The defendant does not have to:
- Do anything with the weapon
- Have the weapon visible
- Intend to use the weapon
Simply having the weapon in one's possession whilst in a public place completes the actus reus.
This type of offence reflects policy decisions about public safety, where the law criminalises potentially dangerous situations even without any harmful action or intent.
Omissions
An omission means a failure to act. English criminal law generally does not impose liability for failures to act – this is sometimes referred to as the absence of a 'Good Samaritan' law.
The general rule
The general rule is that a failure to act does not amount to an actus reus. The law does not usually place an obligation on individuals to take positive action, even when they could easily prevent harm to others.
This reflects principles of individual autonomy and the practical difficulties of enforcing positive duties to act.
Exceptions: categories of duty to act
However, to achieve justice, the law recognises specific categories where a person does have a legal duty to act. Failure to fulfil these duties can result in criminal liability. There are six main categories:
1. Statutory duty to act
Parliament may create specific legal obligations to act through legislation. Failure to comply with these statutory duties can constitute an actus reus.
Examples include:
- Section 1 of the Children and Young Persons Act 1933 (as amended): imposes duties on parents and those with care of children to provide adequate food, clothing, medical aid and lodging
- Section 170 of the Road Traffic Act 1988: requires drivers involved in accidents to stop and provide information
2. Duty arising from special relationship
Certain relationships, particularly family relationships, can create a duty to act.
Worked Example: R v Gibbons and Proctor (1918)
This case established that parents have a duty to care for their children. A father who deliberately withheld food from his child, causing the child's death, was guilty of murder. His partner, who knew about the situation and failed to act, was also liable because she had assumed a parental role.
3. Duty arising from assumption of care
When someone voluntarily assumes responsibility for another person, particularly a vulnerable person, they acquire a legal duty to care for that person.
Worked Example: R v Stone and Dobinson (1977)
The defendants took Stone's elderly sister into their home. She became ill and eventually died from neglect. Despite their own limited abilities, the defendants were convicted of manslaughter because they had assumed a duty of care for her by taking her in. Their failure to summon medical help or otherwise care for her properly constituted a criminal omission.
4. Duty arising from contract of employment
Where a person's employment contract creates a duty to act, failure to perform that duty can result in criminal liability if harm results.
Worked Example: R v Pittwood (1902)
A railway crossing keeper failed to close the gate as required by his contract. A person crossing the railway was struck and killed by a train. Pittwood was convicted because his contractual duty created a legal duty to act, and his failure to do so caused a death.
5. Duty arising from official position
Public officials may have duties to act arising from their position. Failure to act when required can constitute a criminal omission.
Worked Example: R v Dytham (1979)
A police officer stood by and watched as a man was beaten to death outside a nightclub. He took no steps to intervene or summon assistance, and then left the scene. He was convicted because his position as a police officer created a duty to protect the public and prevent crime.
6. Duty to avert a danger of one's own making
If a person creates a dangerous situation, they have a duty to take reasonable steps to prevent or minimise harm arising from that danger.
Worked Example: R v Miller (1983)
The defendant, a squatter, fell asleep whilst smoking a cigarette. He awoke to find the mattress on fire. Rather than attempting to extinguish the fire or summon help, he simply moved to another room and went back to sleep. The house was damaged by fire. Miller was convicted of arson because he had created the dangerous situation and then failed to take any steps to deal with it.
Causation
Where the prosecution must prove that a particular consequence occurred, they must also establish that the defendant's conduct caused that consequence. This involves proving two distinct types of causation:
- Factual causation
- Legal causation
Both must be established for the defendant to be liable for the consequence.
Factual causation: the 'but for' test
Factual causation applies the 'but for' test: but for the defendant's actions, would the consequence have occurred?
If the consequence would have happened anyway, regardless of what the defendant did, then factual causation is not established and the defendant cannot be liable.
For example, if a victim would have died from natural causes at the same time they were attacked, the defendant's actions would not satisfy the 'but for' test because the death would have occurred anyway.
Legal causation
Establishing factual causation alone is not sufficient for criminal liability. The prosecution must also prove legal causation, which examines whether the defendant's conduct made a significant contribution to the consequence.
Worked Example: R v Hughes (2013)
The Supreme Court clarified that legal causation requires more than merely satisfying the 'but for' test. The defendant's conduct must make a meaningful contribution to the consequence.
In Hughes, a driver with no licence or insurance was involved in a fatal collision that was entirely caused by the other driver's actions. Although 'but for' Hughes being on the road the collision would not have occurred, he was not the legal cause of the death because his driving was not at fault. His mere presence on the road was not enough to establish legal causation.
Legal causation essentially looks at whether the defendant's actions contributed substantially to the result, rather than being merely incidental to what happened.
Breaking the chain of causation
Even where both factual and legal causation are established, the defendant may escape liability if a subsequent event breaks the chain of causation. This is known as a novus actus interveniens (a new intervening act).
A novus actus interveniens is an event that occurs after the defendant's initial act but before the final consequence. If this intervening act is sufficiently independent and significant, it can break the chain of causation, meaning the defendant is no longer legally responsible for the final consequence.
Examples of potential intervening acts include:
- Actions by the victim themselves
- Actions by third parties
- Medical treatment
- Natural events
Whether an intervening act breaks the chain of causation depends on how foreseeable and significant the intervening act was. If it was a natural and foreseeable consequence of the defendant's actions, the chain will usually remain intact. Only truly independent and unforeseeable intervening acts will break the chain.
For instance, if a defendant injures a victim who then receives negligent medical treatment, the defendant usually remains liable for the final consequence because medical treatment (even if poor) is a foreseeable result of causing injury.
Key legal terms
Actus reus: The physical element of a crime, consisting of an unlawful act, omission, or state of affairs.
Obiter dicta: Comments made by a judge in a legal judgment that are not essential to the decision. These comments are not binding but may be persuasive in future cases.
Liable: Held to be legally responsible for a breach of the law.
Novus actus interveniens: A subsequent intervening act that breaks the chain of causation between the defendant's conduct and the consequence.
Good Samaritan law: A legal requirement to help others in need. English law generally does not impose such a requirement (except in specific circumstances creating a duty to act).
Exam guidance
When answering problem questions on actus reus:
Identify the type of crime: Determine whether you are dealing with a conduct crime or a consequence crime. If it is a consequence crime, you must address causation.
Consider voluntariness: Was the defendant acting voluntarily? Could involuntariness be raised as an issue?
Check for omissions: If the defendant failed to act rather than acting, identify which (if any) category of duty to act applies. Remember the general rule is no liability for omissions unless a specific duty exists.
Apply causation rules: For consequence crimes, work through both factual and legal causation systematically. Use the 'but for' test for factual causation, then consider whether the defendant's actions significantly contributed to the result. Finally, consider whether any intervening act might break the chain.
Link cases to principles: When citing cases, briefly state the legal principle they establish rather than simply recounting the facts. For example: "In R v Miller (1983), the principle was established that a person who creates a dangerous situation has a duty to take reasonable steps to avert that danger."
Use proper terminology: Demonstrate your legal knowledge by using precise terminology such as actus reus, novus actus interveniens, and the 'but for' test.
Remember!
Key Points to Remember:
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Actus reus is the physical element of a crime – it can be an act, an omission, or simply being in a prohibited situation
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The defendant's actions must be voluntary – involuntary actions (reflexes, fits, being attacked by bees) do not constitute a valid actus reus
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The general rule is no liability for omissions, but there are six key exceptions where a duty to act exists: statutory duty, special relationship, assumption of care, contract of employment, official position, and danger of own making
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For consequence crimes, both factual causation (the 'but for' test) and legal causation (significant contribution) must be proved
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The chain of causation can be broken by a novus actus interveniens – a sufficiently independent intervening act