Learn Criminal law from scratch
1What criminal law is
Criminal law defines the conduct the state punishes: killing, injuring, stealing, damaging property and much more. The state, not the victim, brings the case.
In England and Wales the Crown Prosecution Service decides on charges in most serious cases. In the Netherlands this is the Public Prosecution Service (Openbaar Ministerie).
Because a conviction can lead to prison, the system has strong protections for the accused:
- Presumption of innocence: the accused is treated as innocent until proven guilty.
- Burden and standard of proof: the prosecution must prove guilt beyond reasonable doubt. This is the “golden thread” of Woolmington v DPP.
- Legality: there is no crime without a law defining it beforehand (nullum crimen sine lege). The law must be clear enough to foresee what is punishable (lex certa).
- Ne bis in idem: no one is tried or punished twice for the same offence.
This lesson follows English law, with notes on Dutch law (the Wetboek van Strafrecht, Sr).
Self-check In a theft trial, who must prove what, and to which standard?
- The defendant must prove innocence beyond reasonable doubt
- The defendant must prove innocence on the balance of probabilities
- The prosecution must prove guilt beyond reasonable doubt
- The prosecution must prove guilt on the balance of probabilities
Answer: The prosecution must prove guilt beyond reasonable doubt. Woolmington v DPP places the burden on the prosecution, and the criminal standard is beyond reasonable doubt. The balance of probabilities is the civil standard, used for example in tort and contract cases.
2Actus reus and mens rea
Most offences have two elements. The prosecution must prove both, and they must happen at the same time.
Actus reus is the external element: the conduct, any circumstances, and for result crimes the result (for example a death).
- The act must be voluntary. A reflex or a fit is not an act of the defendant.
- An omission (failure to act) is a crime only if there was a legal duty to act. Duties arise from a contract (a lifeguard), a voluntarily assumed care (Stone and Dobinson), a special relationship such as parent and child, or creating a dangerous situation (R v Evans).
- There is no general duty to help a stranger.
Causation. For result crimes the defendant's act must be a factual cause (but for the act, the result would not have happened) and a legal cause (a more than minimal, operating cause).
- Negligent medical treatment rarely breaks the chain; it must be so independent and potent that the original wound is insignificant (R v Cheshire).
- A free, informed and voluntary act of the victim or a third party can break it (R v Kennedy No 2).
- The thin skull rule: the defendant takes the victim as they find them.
Mens rea is the mental element, the guilty mind. The main forms:
- Direct intention: the result is the defendant's aim or purpose.
- Oblique intention (R v Woollin): the jury may find intention if the result was a virtual certainty and the defendant appreciated this.
- Recklessness (R v G): the defendant was aware of a risk and it was unreasonable to take it.
Strict liability offences need no mens rea for at least one element. Courts presume mens rea is required unless Parliament clearly displaced it (Sweet v Parsley).
Two linking rules: if A aims at B but hits C, A's intention is transferred to C (transferred malice). A continuing act counts once the mens rea appears (Fagan v MPC).
Self-check D, an adult stranger, walks past a pond and sees a child drowning. He could easily help but walks on. The child dies. Is D criminally liable?
- No, because there is no general duty to help a stranger
- Yes, because everyone present has a duty to act
- Yes, because he could easily have saved the child
- Yes, for murder, because he foresaw that the child would die
Answer: No, because there is no general duty to help a stranger. An omission is criminal only if there is a legal duty to act. A passing stranger has no contract, relationship or assumed care, and did not create the danger. Foresight of death does not help without a duty, because there is no actus reus.
3Key offences and defences
Homicide. Murder is the unlawful killing of a human being with intention to kill or to cause grievous bodily harm (GBH). An adult convicted of murder receives a mandatory life sentence.
- Voluntary manslaughter: murder mens rea, but a partial defence applies: loss of control (Coroners and Justice Act 2009) or diminished responsibility (Homicide Act 1957).
- Involuntary manslaughter: no murder mens rea. Either unlawful act manslaughter (a dangerous criminal act causing death) or gross negligence manslaughter (R v Adomako).
- In Dutch law moord (Article 289 Sr) requires premeditation; doodslag (Article 287 Sr) is intentional killing without it.
Non-fatal offences (mostly the Offences Against the Person Act 1861): assault (making the victim apprehend immediate unlawful force), battery (applying unlawful force), actual bodily harm (s 47), wounding or inflicting GBH (s 20) and, most serious, doing so with intent (s 18).
Property offences (Theft Act 1968). Theft is dishonestly appropriating property belonging to another with the intention to permanently deprive the other of it. Robbery is theft with force or the threat of force. Burglary is entering a building or part of one as a trespasser.
Dishonesty is tested by Ivey v Genting Casinos: what did the defendant actually believe about the facts, and was the conduct dishonest by the standards of ordinary decent people?
Defences.
- Self-defence: force that was necessary and reasonable on the facts as the defendant honestly believed them (R v Williams (Gladstone)). A drunken mistaken belief does not count.
- Duress: a threat of death or serious injury. It is not available for murder or attempted murder, or if the defendant voluntarily joined a violent gang (R v Hasan).
- Insanity (M'Naghten Rules) is a disease of the mind from an internal cause, such as epilepsy or sleepwalking. Automatism is loss of control caused by an external factor, such as a blow or an insulin injection; it leads to a full acquittal.
- Intoxication: voluntary intoxication can be a defence to specific intent crimes (such as murder) only if there was no intent. It is no defence to basic intent crimes (DPP v Majewski).
Self-check D attacks V while sleepwalking and causes GBH. He did not know what he was doing. Which defence applies?
- Diminished responsibility
- Insanity, because sleepwalking has an internal cause
- Non-insane automatism, because he acted without control
- Voluntary intoxication
Answer: Insanity, because sleepwalking has an internal cause. In R v Burgess sleepwalking was treated as a disease of the mind, so the defence is insanity. Automatism needs an external cause. Diminished responsibility is a partial defence to murder only, and this is not a murder charge.
4The method for a problem question
Deal with one defendant and one offence at a time. Start with the most serious possible offence.
- Name the offence and its source: statute (with section) or common law.
- Actus reus: identify the act or omission (is there a duty?), the circumstances and the result.
- Causation (result crimes): factual cause, legal cause, and any intervening act that might break the chain.
- Mens rea: which state of mind does the offence require (intention, recklessness, knowledge)? Did the defendant have it at the time of the act?
- Defences: complete ones (self-defence, duress, insanity, automatism) and, for murder, the partial defences.
- Conclude: guilty of which offence, or of a lesser one. Name the leading case for each step you relied on.
5A worked example
Read the facts, then open the steps one at a time. Try to reach each conclusion yourself first.
Worked exampleIn a fight, D stabs V in the stomach, wanting to cause him serious harm. At hospital, the doctors fail to notice a breathing problem caused by the wound, which a careful doctor would have treated. V dies. Is D guilty of murder?
1Murder is a common law offence: the unlawful killing of a human being with intention to kill or cause GBH. V, a human being, has died, and the stabbing was not lawful.
2But for the stabbing, V would not have been in hospital and would not have died. D's act is a factual cause of the death.
3The doctors were negligent, but under R v Cheshire negligent treatment breaks the chain only if it is so independent and potent that the stab wound is insignificant. The breathing problem came from the wound, which was still an operating cause. The chain is not broken.
4D wanted to cause serious harm. That is direct intention to cause GBH, which is enough for murder even though D did not intend to kill.
5Nothing suggests self-defence, a qualifying trigger for loss of control, or an abnormality of mental functioning. No defence applies.
Answer D is guilty of murder: he caused V's death with intention to cause GBH, and the medical negligence did not break the chain of causation.
6Common mistakes
- Confusing motive with intention. A good or different motive does not remove intention.
- Saying that foresight of a likely result is intention. Under Woollin the result must be a virtual certainty and the defendant must appreciate this; even then the jury may find intention, it is not automatic.
- Making omissions criminal without first finding a legal duty to act.
- Treating any medical negligence as breaking the chain of causation.
- Allowing duress as a defence to murder.
- Mixing up insanity (internal cause) and automatism (external cause).
Self-check D sets fire to a house at night to claim the insurance. He knows the family inside will almost certainly die, but hopes they escape. They die. Can the jury find intention to kill?
- No, because he hoped the family would escape
- No, because his purpose was money, not death
- Yes, because death was virtually certain and D appreciated this
- Yes, but only if he wanted the family to die
Answer: Yes, because death was virtually certain and D appreciated this. This is oblique intention under R v Woollin. The jury may find intention when death was a virtual certainty and D knew it. His motive (money) and his hope do not remove that intention.
7How exam questions look
- Easy: key terms and facts. For example: actus reus and mens rea, the standard of proof, the definition of theft, the mens rea of murder.
- Medium: applying the concepts. A short scenario about omissions, causation, assault, theft, robbery or a defence, where you choose the correct result.
- Hard: cases and analysis. The facts of a leading case (Cheshire, Woollin, Jogee, Brown, Majewski…) and you choose what the court held and why.
Ask which element the question tests before you read the options: the act, causation, the mental state or a defence. Wrong options often state a rule that is true for another offence, such as diminished responsibility offered for a non-murder charge.
Some questions use Dutch law: noodweer (self-defence, Article 41(1) Sr), noodweerexces (excessive self-defence caused by strong emotion, Article 41(2) Sr) and dolus eventualis (knowingly accepting a considerable chance of the result).
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