CRIMINAL LAW · FREE QUIZ
Mens rea and actus reus
Level: A-level Law and LLB
Most criminal offences in England and Wales need two things: an actus reus (the guilty act) and a mens rea (the guilty mind), present at the same time. These notes cover the rules and leading cases you need for A-level Law and first-year criminal law. Then test yourself with the free quiz below.
Actus reus: the guilty act
The actus reus is every external element of the offence: the conduct, any circumstances and, for result crimes such as murder, the consequence. The conduct must be voluntary. In Hill v Baxter (1958) the court gave the example of a driver attacked by a swarm of bees, who would not be acting voluntarily.
Omissions
There is no general duty to act in English law, but a failure to act can be the actus reus where the defendant was under a duty. The main duty situations are:
- A contractual duty: R v Pittwood (1902), a railway crossing keeper who left the gate open.
- A duty from a special relationship, such as parent and child: R v Gibbins and Proctor (1918).
- A duty taken on voluntarily: R v Stone and Dobinson (1977).
- A duty from creating a dangerous situation: R v Miller (1983), the cigarette and the mattress fire.
- A duty from a public office: R v Dytham (1979).
- A statutory duty, for example to provide a specimen of breath.
Causation
For result crimes the prosecution must prove both factual and legal causation.
- Factual causation uses the 'but for' test. In R v White (1910) the victim died of a heart attack before the poison could work, so White did not cause her death. He was guilty of attempted murder instead.
- Legal causation: the defendant's act must be an operating and substantial cause of the result, though it need not be the only cause (R v Smith (1959)).
- The thin skull rule: take your victim as you find them. In R v Blaue (1975) the victim refused a blood transfusion for religious reasons, and Blaue was still liable for her death.
- An intervening act can break the chain. A victim's own escape breaks it only if it is so 'daft' that no reasonable person could foresee it (R v Roberts (1971)). Poor medical treatment rarely breaks it unless it is so independent and potent that the original wound becomes insignificant (R v Cheshire (1991); compare R v Jordan (1956)).
Mens rea: the guilty mind
- Direct intention: the defendant's aim or purpose is to bring about the consequence.
- Oblique (indirect) intention: under R v Woollin (1999), the jury may find intention if death or serious injury was a virtual certainty as a result of the defendant's actions, and the defendant appreciated that this was the case.
- Subjective recklessness: the defendant foresaw a risk and unreasonably took it (R v Cunningham (1957)). R v G (2003) overruled the objective Caldwell test for criminal damage.
- Gross negligence: the basis of gross negligence manslaughter (R v Adomako (1994)).
- Strict liability: some regulatory offences need no mens rea for at least one element, for example selling a lottery ticket to someone under 16 in Harrow LBC v Shah (1999).
Coincidence of actus reus and mens rea
The two must exist at the same time, but the courts are flexible. In Fagan v Metropolitan Police Commissioner (1969), driving onto a police officer's foot was treated as a continuing act, so Fagan's later refusal to move supplied the mens rea. In Thabo Meli v R (1954) a series of acts was treated as one transaction.
Transferred malice
If the defendant intends to harm one person but harms another, the mens rea transfers (R v Latimer (1886)). It does not transfer between different kinds of offence: in R v Pembliton (1874) an intention to hit people did not transfer to a broken window.
Test yourself
8 questions. Tap an answer to see whether you're right, and why.
Q1/8A level crossing keeper leaves the gate open while on his lunch break and a cart is hit by a train. Which case says his contractual duty makes this omission the actus reus?
In R v Pittwood the gatekeeper's contract of employment created a duty to close the gate, so his failure to act could found liability for manslaughter.
Q2/8Why was the defendant in R v Miller (1983) liable for arson?
Miller fell asleep with a lit cigarette, woke to find the mattress smouldering and simply moved to another room. Creating the danger gave him a duty to act.
Q3/8D poisons V's drink, but V dies of an unrelated heart attack before the poison takes effect. Following R v White (1910), D is:
V would have died anyway, so D fails the 'but for' test. White was convicted of attempted murder.
Q4/8V is stabbed by D and, for religious reasons, refuses a blood transfusion that would have saved her life. Which principle keeps D liable?
In R v Blaue (1975) the defendant had to take his victim as he found her, including her beliefs, so her refusal did not break the chain of causation.
Q5/8Under R v Woollin (1999), a jury is entitled to find intention where:
Woollin sets the virtual certainty test for oblique intention. Even then, the jury is entitled, not required, to find intention.
Q6/8Which case confirmed that recklessness for criminal damage is subjective, overruling Caldwell?
In R v G the House of Lords held that the defendant must have been aware of the risk. Two boys who did not foresee the fire spreading were not reckless.
Q7/8In Fagan v Metropolitan Police Commissioner (1969), Fagan accidentally drove onto a police officer's foot and then refused to move. Why did actus reus and mens rea coincide?
The battery continued while the car stayed on the foot, so Fagan's decision to leave it there supplied the mens rea.
Q8/8D throws a stone at a group of people, misses and breaks a window. Following R v Pembliton (1874), D's intention to hit the people:
Transferred malice only works within the same kind of offence. Compare R v Latimer (1886), where a blow aimed at one person that injured another did transfer.
Questions
What is the difference between actus reus and mens rea?
Actus reus is the physical part of an offence: the conduct, the circumstances and any consequence. Mens rea is the mental part, such as intention or recklessness. Most offences need both, at the same time.
Can an omission be an actus reus?
Only where the defendant was under a duty to act, for example under a contract (R v Pittwood), because of a relationship (R v Gibbins and Proctor), or because they created a dangerous situation (R v Miller).
What is the Woollin test?
The test for oblique intention: the jury may find intention if death or serious injury was a virtual certainty as a result of the defendant's actions and the defendant appreciated that.
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