24.1 Actus Reus, Mens Rea, Parties and Attempts

Key Takeaways

  • A result crime in England and Wales needs a voluntary act or a duty-based omission, any required circumstances, and factual plus legal causation of the prohibited result.
  • Oblique intention lets a jury find intent where death or grievous bodily harm was a virtual certainty and the defendant appreciated that certainty.
  • An accomplice must intentionally assist or encourage the offence with knowledge of its essential matters; foresight of a further crime is evidence of intent, not a substitute for it.
  • An attempt under the Criminal Attempts Act 1981 requires an act more than merely preparatory and intent to commit the full indictable offence.
  • Attempted murder requires intent to kill; intent to cause grievous bodily harm can found completed murder but does not found the attempt.
Last updated: September 2026

24.1 Actus Reus, Mens Rea, Parties and Attempts

Quick Answer: In England and Wales a specified FLK2 offence is complete only if the prosecution proves the actus reus and the matching mens rea, coinciding in time, against a principal or an accomplice. An attempt under the Criminal Attempts Act 1981 requires an act more than merely preparatory plus intent to commit the full offence. This independent OpenExamPrep chapter applies those building blocks to offences against the person and homicide. Theft, criminal damage and fraud stay in the next chapter.

Why SQE1 tests the building blocks first

SQE1 FLK2 Criminal Liability does not reward a theory essay. It asks you to take a client-shaped narrative and decide whether a named offence is complete, who can be charged, and whether the conduct has even reached an attempt. The SRA FLK2 list treats the definition of the offence (actus reus and mens rea), parties (principal offender and accomplices), and inchoate liability (attempt to commit an offence) as tools you then apply to common assault, the Offences Against the Person Act 1861 (OAPA 1861) ss.47, 20 and 18, murder and manslaughter.

If you skip this section, later questions on wounding, loss of control or self-defence collapse. You cannot test a defence until you know which ingredients the Crown must prove, and you cannot advise a police-station client until you know whether they are being treated as the person who struck the blow or as the person who drove the van.

Actus reus: conduct, circumstances and result

Actus reus is the external side of the offence. For a result crime such as s.47 actual bodily harm or murder it usually has three pieces.

PieceWhat the Crown must proveTypical person-offence example
ConductA voluntary act, or a qualifying omissionA punch, a shove, a failure to summon help where a duty exists
CircumstancesFacts that make the conduct criminalThe force is unlawful; the victim is a human being in being
ResultThe prohibited consequence, caused by DBruising (ABH), a wound, really serious harm, death

The act must be voluntary. If D is thrown onto V, or D's limbs move in a true spasm, there is no actus reus. Drowsiness from drink is not involuntariness: that is an intoxication problem, not a missing act.

Omissions. English and Welsh law does not punish a failure to act unless a duty to act exists. For SQE1, recognise five recurring duty sources:

  1. Statute — a written duty to do a positive act.
  2. Contract — for example a paid crossing-keeper who leaves a gate unattended.
  3. Special relationship — parent and dependent child; some carer relationships.
  4. Voluntary assumption of care — D takes V into their home and undertakes to look after V, then starves or neglects V.
  5. Creation of a dangerous situation — D accidentally starts a fire or otherwise creates a hazard and then fails to take reasonable steps to undo the danger.

If none of those duties exists, walking past a stranger in danger is not an offence against the person, however morally stark the facts. Exam writers love a bystander who looks callous but is not legally bound to intervene.

Causation on result crimes. Prove factual cause and legal cause.

  • Factual cause is the but-for test: but for D's conduct, would the result have occurred when it did? If V would have died at the same moment from an independent heart attack, but-for fails.
  • Legal cause requires D's conduct to be an operating and substantial cause. It need not be the only cause. A thin-skull victim who refuses a blood transfusion for religious reasons, or who has an unusually fragile skull, does not break the chain: D must take V as D finds V, including beliefs and vulnerabilities.
  • Medical treatment almost never breaks the chain. Treatment breaks it only if it is so independent of D's acts and so potent in causing death that D's conduct is relegated to history.
  • V's own escape can break the chain only if it is so daft or disproportionate that it is not a reasonably foreseeable response to D's wrong.
  • A free, deliberate and informed act of a third party can break the chain, but reasonably foreseeable reactions (including police returning fire when D uses V as a shield) usually do not.

Coincidence. Mens rea and actus reus must coincide. Two working tools save apparently split facts:

  • Continuing act: D drives onto V's foot by accident; once D knows and refuses to move, the battery continues and the later mens rea coincides.
  • Single transaction: D thinks V is dead and dumps the body, and V actually dies in the dumping. If it is one planned sequence, the intent from the attack runs through the disposal.

Transferred malice. If D aims a blow at A with the mens rea for an offence against the person and hits B, the mens rea transfers to B. It does not hop onto a different type of offence (for example intending to hit a person but breaking a window).

Mens rea: intention, recklessness and the offence-specific match

Mens rea is the fault element the statute or common law requires for that offence. Do not recycle a generic guilty mind.

FaultCore test in England and WalesFLK2 use
Direct intentionD's aim or purpose is the resultMurder; s.18 intent to cause GBH
Oblique intentionDeath or GBH is a virtual certainty and D appreciates that; the jury may then find intentionMurder where D's purpose is something else (destroy a building, silence an alarm)
Subjective recklessnessD foresaw a risk of the relevant harm and unreasonably took itMaliciously in s.20; many basic-intent offences
Negligence / gross negligenceObjective falling below a duty; gross is for the jury in manslaughterGross negligence manslaughter only

Murder is not a recklessness crime. Planting a bomb not wanting the night-watchman to die is still murder if death was a virtual certainty and D appreciated that.

Match the mens rea to the result the offence names. For s.47, the Crown needs the mens rea of assault or battery, not foresight of actual bodily harm. For s.20, maliciously means intention or subjective recklessness as to some physical harm, not necessarily a wound or grievous bodily harm. For s.18, the Crown needs a specific intent to cause GBH (or to resist or prevent lawful apprehension). Mixing those three tests is the most common SQE1 trap in this topic.

Parties: principal and accomplices

The principal is the person who commits the actus reus with the required mens rea, including through an innocent agent (a child or an unaware adult used as a tool).

Everyone who aids, abets, counsels or procures the offence may be tried and punished as if they were a principal (Accessories and Abettors Act 1861, s.8).

ModeTypical conductTiming
AidPractical help: lookout, driving, supplying the weaponUsually at the scene
AbetEncouragement at the sceneDuring
CounselAdvice or encouragement beforehandBefore
ProcureCause the offence to be committed; no shared plan is neededBefore or during

The accomplice must intentionally assist or encourage and must know the essential matters that make the principal's conduct an offence of that type. D does not need to know the precise time, place or victim if D intends to assist a crime of that type, or a crime within the range D contemplated.

Foresight is not enough on its own. An accomplice is not guilty of a further crime merely because they foresaw that the principal might commit it. Foresight is evidence from which a jury may infer intention to assist or encourage. If your client handed over a van for a burglary and the driver then committed a different offence outside the range your client intended to assist, accessory liability for that further offence is not automatic.

Withdrawal. An accomplice who wants out must communicate withdrawal in good time. If they have already supplied significant help, they may need to take reasonable steps to undo that help (recovering a weapon, warning the victim). Silent regret is not withdrawal.

Attempt

Under the Criminal Attempts Act 1981, s.1, D is guilty of attempting an indictable offence if D does an act that is more than merely preparatory to the commission of the offence, with intent to commit that offence.

  • Planning, reconnaissance, buying a weapon, and travelling towards the scene are usually still preparatory.
  • Once D is in the process of committing the offence itself — pointing a loaded gun at V, raising a knife to stab, forcing a door to get at V — the jury may find the act more than merely preparatory.
  • Impossibility is no defence if the facts had been as D believed them (the pocket is empty; the body is a mannequin).
  • Attempted murder requires intent to kill. Intent to cause GBH, which suffices for murder as a completed offence, does not suffice for attempted murder.
  • Common assault is summary-only (Criminal Justice Act 1988, s.39), so it is not a 1981 Act attempt. Ss.47, 20 and 18 can be attempted, but the intent must be to commit that full offence.

Putting it together on an SQE1 fact pattern

Work in this order: (1) identify the specified offence in play; (2) list its actus reus; (3) list its mens rea; (4) test coincidence, causation and transferred malice; (5) ask who was principal and who intentionally assisted; (6) if the result never occurred, ask whether D went beyond preparation with the full intent; (7) only then turn to general or partial defences.

Official starting points: the SRA SQE1 FLK2 Assessment Specification (Criminal Liability: definition of the offence, parties, attempt), the Criminal Attempts Act 1981, s.1, and the Accessories and Abettors Act 1861, s.8.

Test Your Knowledge

A woman agrees to stand in the street and shout if anyone approaches while a man punches a neighbour in a doorway. She intends to help him land the punches. The neighbour suffers bruising that amounts to actual bodily harm. The woman never touches the neighbour. Which statement best describes her potential liability for the s.47 offence?

A
B
C
D
Test Your Knowledge

A man buys a kitchen knife, writes the victim's address on a scrap of paper, and is arrested two streets away from the victim's house walking in that direction. He admits he intended to cause the victim really serious harm. He has not yet reached the street where the house stands. Is he guilty of attempting to cause grievous bodily harm with intent?

A
B
C
D
Test Your Knowledge

An adult daughter moves into her father's flat and tells neighbours she will cook, wash and give him his medication. Over several weeks she stops feeding him. He develops pressure sores and dehydration amounting to actual bodily harm. She never hits him. Which statement best explains whether a duty to act can found the actus reus?

A
B
C
D
Test Your Knowledge

A defendant plants an incendiary device to destroy a warehouse at night. He does not want anyone to die, but he knows a night-watchman is inside and that the watchman's death is a virtual certainty. The watchman dies. Which statement best describes murder mens rea?

A
B
C
D