In the criminal law of England and Wales, for a person to be found guilty of most criminal offences, the prosecution must prove two fundamental elements beyond reasonable doubt. These are the actus reus, which is the external or physical element of the crime, and the mens rea, the internal or mental element. The principle is often summarised by the Latin maxim actus non facit reum nisi mens sit rea, meaning 'an act does not make a man guilty of a crime unless his mind is also guilty'. This essay will explain the components of both actus reus and mens rea and discuss the principle that they must coincide in time to establish criminal liability.
The Actus Reus: The Guilty Act
The actus reus is the prohibited conduct, consequence, or state of affairs that the law seeks to prevent. It is the objective, physical component of an offence. For an actus reus to be established, the defendant’s conduct must be voluntary. If a person's actions are involuntary, they cannot be held criminally responsible. For example, in Hill v Baxter [1958] 1 QB 277, it was suggested that a driver who lost control of a car because they were stung by a swarm of bees would not be acting voluntarily and therefore would not have committed the actus reus of a driving offence. The actus reus can consist of an act, a state of affairs, or, in certain situations, an omission.
Generally, there is no criminal liability for a failure to act, as there is no ‘Good Samaritan’ law in England and Wales. However, liability for an omission can arise where the law recognises that the defendant was under a duty to act. Such duties can be imposed by statute, arise from a contract, or be recognised at common law. Common law duties include those based on a special relationship, such as a parent to their child, or where a person has voluntarily assumed a duty of care for another (Herring, 2022). Furthermore, a duty to act can be created where a person has caused a dangerous situation. In R v Miller [1983] 2 AC 161, the defendant accidentally set a mattress on fire and, upon realising, did nothing to extinguish it. The House of Lords held that his failure to act upon becoming aware of the fire constituted the actus reus of arson.
The Mens Rea: The Guilty Mind
The mens rea refers to the state of mind of the defendant at the time of the actus reus. It is the element of fault or blameworthiness required for a criminal offence. The two most common forms of mens rea are intention and recklessness. Intention can be further divided into direct intent and oblique intent. Direct intent is where the defendant’s aim or purpose is to bring about the prohibited consequence. Oblique intent is more complex and arises where the consequence is not the defendant's primary purpose but is a virtually certain result of their actions, and the defendant appreciates that it is a virtually certain result. The leading authority for this is R v Woollin [1999] AC 82, where the House of Lords established that a jury is entitled to find the necessary intention if the outcome was a virtual certainty of the defendant's actions and the defendant recognised this.
Recklessness involves taking an unjustified risk. The current test for recklessness in criminal damage, and by extension in most offences against the person, is a subjective one, as established in R v G and another [2003] UKHL 50. This test asks whether the defendant was aware of a risk and, in the circumstances known to them, it was unreasonable to take that risk. This overruled the previous objective test from Metropolitan Police Commissioner v Caldwell [1982] AC 341, which had been criticised for potentially convicting defendants who genuinely had not foreseen a risk that a reasonable person would have.
The Coincidence of Actus Reus and Mens Rea
A core principle of criminal liability is that the actus reus and mens rea must coincide in time. This is known as the principle of temporal coincidence. However, the courts have shown flexibility in applying this rule to avoid unjust outcomes. One way this is achieved is through the ‘continuing act’ theory. In Fagan v Metropolitan Police Commissioner [1969] 1 QB 439, the defendant accidentally drove his car onto a police officer’s foot (the actus reus without mens rea) but then knowingly refused to move it (forming the mens rea). The court held that the act of driving onto the foot and remaining there was a continuing act, so the later formation of intention coincided with the ongoing actus reus. Another approach is the ‘one transaction’ principle, used in cases like Thabo Meli v R [1954] 1 WLR 228, where the defendants attacked a victim and, believing him to be dead, threw him off a cliff. The victim actually died from exposure at the bottom of the cliff. The court treated the entire sequence of events as a single transaction, and since the defendants had the mens rea for murder at some point during that transaction, they were found guilty.
In conclusion, actus reus and mens rea are the essential elements that form the basis of most criminal offences. The actus reus constitutes the physical conduct, which must be voluntary and can include omissions where a duty to act exists. The mens rea constitutes the defendant's blameworthy mental state, most commonly intention or recklessness. For liability to be established, these two elements must exist at the same point in time, a principle the courts have applied flexibly to ensure that legal outcomes reflect the defendant's culpability.
References
- Herring, J. (2022) Criminal Law: Text, Cases, and Materials. 10th edn. Oxford University Press.
- Fagan v Metropolitan Police Commissioner [1969] 1 QB 439.
- Hill v Baxter [1958] 1 QB 277.
- Metropolitan Police Commissioner v Caldwell [1982] AC 341.
- R v G and another [2003] UKHL 50.
- R v Miller [1983] 2 AC 161.
- R v Woollin [1999] AC 82.
- Thabo Meli v R [1954] 1 WLR 228.
