Actus reus


After reading this chapter you should be able to:

Understand when liability can be imposed for a failure to act (an omission) Understand the rules on factual causation, the ‘but for’ test

Understand the rules on legal causation

Analyse critically the laws on omissions and causations

Apply the law to factual situations to determine whether there is liability for a failure to act or whether there has been a break in the ‘chain of causation’

This chapter examines the physical elements that are required to be proved for liability to be imposed. The Latin phrase ‘actus reus’ is used as a convenient shorthand for describing all the physical elements that go to make up different criminal offences.

2.1 The physical element

The majority of criminal offences considered in this textbook require as a starting point some physical element on the part of the defendant (D). Precisely what that physical element is depends on the criminal offence. To give some examples:

Murder and manslaughter require, in most cases, that D does an act which causes the death of the victim (V) (see Chapter 10).

Battery requires that D applies unlawful force to the body of the victim. The crime of malicious wounding requires that D does some act which cuts the skin of the victim (see Chapter 11).

Rape requires that D ‘penetrates’ the vagina, anus or mouth of the victim with his penis and without V’s consent (see Chapter 12).

Theft requires that D ‘appropriates’ ‘property’ which ‘belongs to another’ person (see Chapter 13).

2.1.1 Conduct and consequences

You will see that the physical element in murder actually subdivides into two elements: an act (conduct) and death (consequence). The act part could be, for example, aiming a gun at V and pulling the trigger; stabbing V with a knife; strangling V with a piece of cord; or pushing V from the top of a tall building (no doubt you can think of plenty of other examples). The consequence that must follow from D’s act, namely the death of V, is also part of the physical element. In most cases death follows fairly swiftly after D’s act but, in some cases, there may be a delay of minutes, hours, days or even longer. Has D caused V’s death if he strangles her, leaving her in a coma as a result of hypoxia (loss of oxygen to the brain) from which she eventually dies six months later? It is impossible to give a definite answer to this question; it is a question of fact for a jury. However, there are a number of legal principles which exist to help a jury in such cases and these will be examined below.

With malicious wounding, the conduct and consequence could be regarded as inseparable: the act of stabbing or slashing at V with a knife, broken bottle, etc (conduct) must cause V’s skin to be cut (consequence). In battery, the physical element requires conduct (applying force to V’s body) but there is no consequence requirement. Similarly, in rape there is a conduct requirement (penetration) but no consequence is required. Theft is another example: there is a conduct element (D must ‘appropriate’, which means to assume rights over, property) but there is no consequence requirement.

2.1.2 Circumstances

Some criminal offences require certain circumstances to exist in addition to the conduct/consequence elements. One of the physical elements required in rape is that V must not have consented. This is a circumstance that must exist at the time D penetrates V’s vagina, anus or mouth, and without it there is no crime. Similarly, in theft, in addition to the conduct element of appropriating, there must be ‘property’ that ‘belonged to another’ at the time of the appropriation. D, a vagrant, might assume rights of ownership over an old, worn-out shoe that he finds lying in the street, but this would probably not be enough to satisfy all the physical elements in the crime of theft, as it is likely that the shoe has been abandoned and hence is ownerless.

2.1.3 The physical element alone is not a crime

Look again at the conduct elements of the crimes above. In none of the cases does it automatically follow that D has committed a crime. In most rape cases, the conduct element is penetration of V’s vagina or anus by D’s penis, which are, generally speaking, perfectly lawful activities (subject to V having attained the age of consent, which in England is 16 (Sexual Offences (Amendment) Act 2000). In theft, the conduct element is ‘appropriating’ property, an act which does not imply any wrongdoing. If you are reading this book whilst sitting at a desk in a library, you are ‘appropriating’ the seat and the desk because you are assuming rights of ownership over them (albeit temporarily). What prevents this performance of the physical element from amounting to a criminal offence is, in some cases, the lack of other physical elements. Thus, for D to use his penis to penetrate V’s vagina, anus or mouth is, generally speaking, not the crime of rape, because V consents. In other cases, all the physical elements (whether conduct, consequences or circumstances) may be present, but still the crime may not be committed because the mental element of the crime is missing. Thus, in order to commit theft, it is necessary that D has the ‘intention to permanently deprive’ the owner of their property and that D was ‘dishonest’. Someone sitting innocently at a library desk does not have either the requisite intent or the dishonesty. There are exceptions to this rule, however. Some criminal offences may be committed with no, or a very little, mental element. These crimes are known as ‘absolute’ or ‘strict’ liability offences and will be examined in Chapter 4.

2.1.4 Omissions

It was stated above that, in murder and manslaughter, ‘in most cases’ D must do some act which causes death. The exception is where D does nothing to prevent V’s death. In certain circumstances, D may be under a duty to take positive steps to assist V and failing to take them can amount to the physical element of the crimes of murder and manslaughter. This topic will be examined below.

2.2 Voluntary conduct

In Bratty v Attorney-General of Northern Ireland (1963) AC 386, Lord Denning said that: ‘The requirement that [the act of the accused] should be a voluntary act is essential … in every criminal case. No act is punishable if it is done involuntarily.’ An example of this might be if the defendant, D, were to push a bystander, E, so that E lost his balance and knocked a second bystander, V. If V loses his balance and falls to the ground, fracturing his leg, has E committed the actus reus of battery or even assault occasioning actual bodily harm? The actus reus of battery requires the unlawful application of physical force to the body of the victim; the actus reus of actual bodily harm is the same plus the infliction of some hurt or injury to the victim. The answer is that E is not guilty of any crime: although E was the immediate cause of V’s falling to the ground and hence his injuries, in no sense can E be said to have ‘acted’. Moreover, even if E could be said to have performed an ‘act’ in the above scenario, it was clearly not ‘voluntary’ in the sense of being a deliberate or willed ‘act’ on his behalf. (These are the facts of Mitchell (1983) QB 741. V, aged 89, died of a pulmonary embolism caused by thrombosis, which in turn was caused by the fracture. In the event, D (and not E) was charged and convicted of her manslaughter.)

2.3 Omissions

Originally, the English criminal law only punished those who caused a prohibited result by a positive act. But it came to accept that it should also punish those who fail to act, when a duty to act could be implied, with the result that the prohibited result ensued. Nevertheless, on the whole, the position is still that there is no general duty to act. There may well be a moral obligation on someone to be a ‘Good Samaritan’, but there is not a legal one. There are two requirements:

The crime has to be capable of being committed by omission (known as result crimes).

D must be under a duty to act.

2.3.1 Commission by omission

Generally speaking, the crime must be capable of being committed by omission. Nearly all of the leading cases involve murder or gross negligence manslaughter. Other crimes capable of being committed by omission are arson (Miller (1983) 2 AC 161, which will be discussed below) and assault and battery. This was decided in DPP v Santana-Bermudez (2003) EWHC 2908.


DPP v Santana-Bermudez (2003) EWHC 2908

V, a female police officer, asked D to turn out all his pockets, which he did. V asked him if he had removed everything; he replied ‘Yes’. She then asked ‘Are you sure that you do not have any needles or sharps on you?’ D said ‘No’. V commenced her search but when she put her hand into one pocket she pricked her finger on a hypodermic needle. V noticed that D was smirking. D was convicted of assault by magistrates, but appealed to the Crown Court, successfully arguing that it was legally impossible to commit an assault by omission. The prosecution appealed to the Divisional Court, which allowed the appeal.

Conversely, a crime that is incapable of being committed by omission is constructive manslaughter (a positive act is always required, according to Lowe (1973) QB 702; see Chapter 10). Sometimes the definition of the actus reus makes it clear that a positive act is required. For example, burglary (s 9 of the Theft Act 1968 requires D to ‘enter’ into a building; see Chapter 14) and making off without payment (s 3 of the Theft Act 1978 requires D to ‘make off’; see also Chapter 14). The definition of rape in s 1(1) of the Sexual Offences Act 2003 makes clear that the offence is committed only when D ‘penetrates the vagina, anus or mouth of another person with his penis’. Section 79(2) of the same Act states that ‘penetration is a continuing act’. This would seem to rule out any possibility of committing rape by omission (although see the discussion of the cases of Kaitamaki (1984) 2 All ER 435 and Cooper and Schaub (1994) Crim LR 531 on this point in Chapter 12). Another example is the offence of ‘throwing missiles’ (s 2 Football Offences Act 1991). In Ahmad (1986) Crim LR 739, D, a landlord, was convicted of ‘doing acts calculated to interfere with the peace and comfort of a residential occupier with intent to cause him to give up occupation of the premises’, contrary to the Protection from Eviction Act 1977. The relevant acts had been done without the requisite intent; D had then deliberately refrained from rectifying the situation. The Court of Appeal quashed the conviction; D had not ‘done acts’ with the requisite intent.

One problem with the imposition of liability for failing to act in ‘result’ crimes, such as murder and gross negligence manslaughter, which the courts have not really acknowledged, is the requirement of causation. Suppose D, a professional lifeguard on duty, sees a small child fall into a pool, but simply stands and watches while she struggles and eventually drowns. No one else is present. There is little doubt that D is under a duty to save the girl (because of contractual responsibility; see below) and failure to do so could well be murder (if D intends death or serious injury) or gross negligence manslaughter. But did D ‘cause’ the girl to die? She would almost certainly have died in exactly the same way — the same ‘result’ would have occurred — had she been completely alone and D had not been there. The Law Commission tackles this when it provides in its Draft Criminal Code (1989), clause 17(1), that ‘a person causes a result … when … (b) he omits to do an act which might prevent its occurrence and which he is under a duty to do according to the law relating to that offence’.

2.3.2 Imposition of a duty to act

The most important factor is that D must be under a duty, recognised by the law, to act or intervene in the circumstances. In Khan and Khan (1998) EWCA Crim 971; (1998) Crim LR 830, the Court of Appeal quashed manslaughter convictions of two drug dealers because the judge had made no ruling as to whether the facts were capable of giving rise to any relevant duty, nor had he directed the jury in relation to that issue.


Khan and Khan (1998) EWCA Crim 971; (1998) Crim LR 830

D and E were drug dealers in Birmingham. V, a 15-year-old prostitute, went to a flat where they supplied her with heroin. She ingested a large amount, lapsed into a coma and was obviously in need of medical assistance. However, D and E left the flat, leaving V alone to die. They were charged with murder but were convicted of manslaughter. The Court of Appeal quashed their convictions. The Crown’s case was that the appellants’ omission ito summon medical assistance formed the basis of their liability. However, the Court of Appeal decided that, in such circumstances, before they could convict, the jury had to be sure that D was criminally responsible, and this required that D be standing in such a relation to the victim that he is under a duty to act.

It should be noted that the above case does not decide that no duty was (or could be) owed on the facts; rather that it must be left to the jury to decide whether, on the facts, a duty was in fact owed. Such a duty may be owed in a variety of situations, as the following cases illustrate.

Duty arising out of contractual liability

Where failure to fulfil a contract is likely to endanger lives, the criminal law will impose a duty to act. The duty is owed to anyone who may be affected, not just the other parties to the contract. The leading cases are Pittwood (1902) 19 TLR 37 and Adomako (1995) 1 AC 171. In Pittwood, D was a signalman employed by the railway company to look after a level crossing and ensure the gate was shut when trains were due. D left the gate open and was away from his post, with the result that someone crossing the line was hit and killed. D was convicted of manslaughter. The court rejected D’s argument that his duty was owed simply to the railway company: he was paid to look after the gate and protect the public. This duty will be held by members of the emergency services, lifeguards, etc. In Adomako, a duty to act was imposed on a hospital anaesthetist (see Chapter 10). In Singh (1999) EWCA Crim 460; (1999) Crim LR 582, a duty to act was imposed on a landlord. D, who helped his father run a lodging house, was convicted of manslaughter after carbon monoxide poisoning from a defective gas fire killed one of the tenants. On appeal he contended that no duty to act had arisen, whether as rent collector, maintenance man, or anything else. However, the Court of Appeal decided that, as it was D’s responsibility to maintain the flat, a duty to act was imposed on him to deal with any danger by calling in expert help.

Duty arising out of a relationship

Parents are under a duty to their children (Gibbins and Proctor (1918) 13 Cr App R 134) and spouses owe a duty to each other (Smith (1979) Crim LR 251; see Hood (2003) EWCA Crim 2772 below).

Duty arising from the assumption of care for another

A duty will be owed by anyone who voluntarily undertakes to care for another person, whether through age, infirmity, illness, etc. The duty may be express but is more likely to be implied from conduct. Thus in Nicholls (1874) 13 Cox CC 75, D, a grandmother who took her granddaughter into her home after the girl’s mother died, was held to have undertaken an express duty to act. In Instan (1893) 1 QB 450, D moved in with her elderly aunt, who became ill and for the last 12 days of her life was unable to care for herself or summon help. D did not give her any food or seek medical assistance, but continued to live in the house and eat the aunt’s food. Eventually the aunt died and D was convicted of manslaughter. In Gibbins and Proctor, the court found that the deliberate non-performance of a legal duty to act could result in liability for murder being imposed on D, who had voluntarily undertaken responsibility to care for a child.


Gibbins and Proctor (1918) 13 Cr App R 134

G was the father of several children, including a seven-year-old daughter, Nelly. His wife had left him and he was living with a lover, P. They kept Nelly separate from the other children and deliberately starved her to death. Afterwards they concocted a story about how Nelly had ‘gone away’; in fact G had buried her in the brickyard where he worked. Both adults were convicted of murder and the Court of Criminal Appeal upheld the convictions. G owed Nelly a duty as her father; P was held to have undertaken a duty.

The leading case is now Stone and Dobinson (1977) QB 354.


Stone and Dobinson (1977) QB 354

S lived with his mistress, D. In 1972, S’s sister, Fanny, aged 61, came to live with them. Fanny was suffering from anorexia nervosa and although initially capable of looking after herself, her condition deteriorated. Eventually, in 1975, she was confined to bed in the small front room where she remained until her death, refusing to eat anything other than biscuits. S was then 67, partly deaf, nearly blind and of low intelligence. D was 43 but was described as ‘ineffectual’ and ‘somewhat inadequate’. Both were unable to use a telephone. They had tried to find Fanny’s doctor but failed; eventually a local doctor was called, but by this point it was too late. Fanny had died, weighing less than 5 1/2 stone, in an excrement-and urine-soiled bed with two large, maggot-infested ulcers on her right hip and left knee, and bone clearly visible. The Court of Appeal upheld S and D’s manslaughter convictions. They had assumed a duty of care to Fanny, and their pathetically feeble efforts to look after her amounted to gross negligence.


Self-test question

Would Stone and Dobinson have been better off simply ignoring Fanny after she became bedbound?

Duty arising from the creation of a dangerous situation

Where D inadvertently, and without the requisite mens rea, does an act which creates a dangerous situation then, on becoming aware of it, he is under a duty to take all such steps as lie within his power to prevent or minimise the harm. If he fails to take such steps with the appropriate mens rea, then he will be criminally liable. This situation arose in Miller.


Miller (1983) 2 AC 161

D, a vagrant, was squatting in a house in Birmingham. He had fallen asleep one night but i awoke to find that a cigarette he had been smoking had set fire to the mattress. He did i nothing to extinguish the fire, but moved to another room and went back to sleep. The i house caught fire, and £800 damage was caused. The House of Lords upheld his conviction, on the basis that his inadvertent creation of a dangerous situation imposed a duty on him to take steps to minimise that danger as soon as he realised what he had done. What those steps are will depend on what is reasonable in the circumstances. At the least, D might have been expected to try to put out the fire or, if it was beyond control, call the: fire brigade.

A number of subsequent cases have discussed the Miller principle.

In Matthews and Alleyne (2003) EWCA Crim 192; (2003) Crim LR 553 (the full facts 33 of which appear in the next chapter in the context of intention) the trial judge O suggested that D and E could have been convicted of murder if, having pushed I V into a river, they subsequently realised that he was unable to swim and (with I intent that he should die or suffer serious injury) took no steps to rescue him. The appellants and V were strangers to each other prior to this event, so the basis on s which D and E owed V a duty to act could be regarded as similar to that in Miller.

In Santana-Bermudez, the facts of which were given above, the Divisional Court expressly applied Miller as the basis for finding D’s duty to act. The court held that, when D gave V a dishonest assurance about the contents of his pockets, he exposed her to a reasonably foreseeable risk of injury. His subsequent failure to inform her of the presence of needles in his pockets constituted an evidential basis for a finding that the actus reus of assault occasioning actual bodily harm had occurred.

The most recent example of the Miller principle is the case of Evans (2009) EWCA Crim 650; (2009) 1 WLR 1999, in which the principle was applied to gross negligence manslaughter.


Evans (2009) EWCA Crim 650; (2009) 1 WLR 1999

ID lived with her 16-year-old half-sister, V, a heroin addict, and their mother. One day, D bought £20 of heroin and gave some to V, who self-injected. Later, it was obvious that had overdosed but neither D nor their mother contacted the emergency services. Instead they put V to bed hoping that she would recover. Instead, she died during the night. Both D and her mother were convicted of gross negligence manslaughter. D appealed, but the Court of Appeal upheld the conviction on the basis that D owed V a duty of care based on the Miller principle.

Lord Judge CJ stated:


‘The duty necessary to found gross negligence manslaughter is plainly not confined to cases of a familial or professional relationship between [D] and [V]. In our judgment, consistently with Adomako and the link between civil and criminal liability for negligence, for the purposes of gross negligence manslaughter, when a person has created or contributed to the creation of a state of affairs which he knows, or ought reasonably to know, has become life threatening, a consequent duty on him to act by taking reasonable steps to save the other’s life will normally arise.’

The Draft Criminal Code (1989), clause 23, also endorses the Miller principle:


‘23 Where it is an offence to be at fault in causing a result, a person who lacks the fault required when he does an act that causes or may cause the result nevertheless commits the offence if —

a.he has become aware that he has done the act and that the result had occurred and may continue, or may occur; and

b.with the fault required, he fails to do what he can reasonably be expected to do that might prevent the result continuing or occurring; and

c.the result continues or occurs.’

Clause 31 of the Draft Criminal Law Bill (1993) is to similar effect.

Release from duty to act

One issue that has troubled the courts is whether D, having undertaken a duty or having had one imposed on him, may be released from it. In Smith (1979), D’s wife had given birth to a stillborn child at home. She hated doctors and would not allow D to call one. When she finally gave D permission it was too late; she died and D was charged with manslaughter. The judge directed the jury ‘to balance the weight that it is right to give to his wife’s wish to avoid calling a doctor against her capacity to make rational decisions. If she does not appear too ill it may be reasonable to abide by her wishes. On the other hand, if she appeared desperately ill then whatever she may say it may be right to override’. The jury was unable to agree and D was discharged. The principle that, provided V is rational, she may release D from a duty to act was confirmed in Re B (Consent to Treatment: Capacity) (2002) EWHC 429 (Fam); (2002) 2 All ER 449. Here, the High Court held that, when a competent patient gives notice that they wish life-preserving treatment to be discontinued, anyone responsible up to that point for providing such treatment (in this case doctors) would be obliged to respect that notice.

Cessation of duty to act

In Airedale NHS Trust v Bland (1993) AC 789 (like Re B, a civil case), the House of Lords provided guidance on the issue of when a duty to act ceases. Bland, who had been suffocated during the Hillsborough Stadium tragedy in 1989, had been in a persistent vegetative state in hospital for over three years. When the hospital authorities applied for judicial authority to discontinue treatment in the form of artificial feeding and hydration, the House of Lords held that, on the facts, it was permissible to do so. Lord Goff, giving the leading judgment, stated that there was no absolute rule that a patient’s

life had to be prolonged regardless. The fundamental principle was the sanctity of life, but respect for human dignity demanded that the quality of life be considered. The principle of ‘self-determination’ meant that an adult patient of sound mind could refuse treatment. Doctors (or other persons responsible for the patient) would have to respect that. In Bland, the House of Lords was careful to characterise the withdrawal of life support as an omission (a failure to continue treatment). The case does not stand as an authority for the proposition that doctors may take positive steps to end a patient’s life. Euthanasia, therefore, remains illegal in England and Wales.

The crime of assisting another’s suicide is also unaffected by the Bland decision. This was demonstrated in R (on the application of Pretty) v DPP (2001) UKHL 61; (2002) 1 AC 800. P was suffering from motor neurone disease which she knew would eventually lead to her suffocating to death. She applied to the courts for a judicial declaration that, if her husband assisted her to commit suicide, he would not be prosecuted (her physical condition having deteriorated to such an extent by this point that she was unable to take her own life unassisted). This request was denied by the High Court and confirmed by the Court of Appeal and House of Lords. Assisting another person to commit suicide seems, inevitably, to amount to a positive act. A final appeal to the European Court of Human Rights also failed, the Court in Strasbourg ruling that English law did not infringe P’s human rights.

In Re A (Children) (Conjoined Twins: Surgical Separation) (2000) EWCA Civ 254; (2000) 4 All ER 961, the Court of Appeal (Civil Division) confirmed that a surgical procedure to separate two baby girls who were born joined together at the abdomen was a positive act and not an omission. Therefore, because the doctors knew that the procedure would inevitably lead to the death of one girl, the doctors had both the actus reus and mens rea