WHAT IS ACTUS REUS? → it is the physical element of a crime. It can be:

  • an act

  • a failure to act (omission)

  • a 'state of affairs'

The act/omission must be voluntary on the part of D. If D has no control over his actions, then he has not committed the offence. In Hill v Baxter 1958, the court gave examples of where a driver lost control of his vehicle because he was stung by a swarm of bees, struck on the head by a stone or had a heart attack whilst driving.

    • Kay v Butterworth: D fell asleep whilst driving and killed people. D's conduct was voluntary as he has chosen to drive even though he knew he was tired.

Transferred malice applies when it comes to AR (Mitchell 1983). There are also rare instances in which D has been convicted even though they did not act voluntarily. These situations involve what are known as 'state of affairs' cases (Larsonneur 1933)

Prosecution has to prove that D committed the AR voluntary → Article 6 European Convention of Human Rights → innocent until proven guilty.

OMISSIONS? The normal rule is that an omission cannot make a person guilty of an offence!

Exceptions to this rule

There are exceptions to this rule, an an omission can make a person guilty of an offence. An omission is only sufficient for the AR where there is a duty to act. There are 6 ways in which such a duty can exist:

  1. A statutory duty: an Act of Parliament can create liability for an omission

    • s170 Road Traffic Act 1988: failing to stop and report a traffic accident.

    • s6 Road Traffic Act 1988: failing to provide a specimen of breath

    • s5 Domestic Violence, Crime and Victims Act 2004: applies where a person in the same household fails to take such steps as they reasonably could have to protect the victim.

  1. A contractual duty: this is where an employee fails to do their duty, and as a result someone is injured. This would make him guilty of an offence (Pitwood 1902).

  2. A duty because of a relationship: this is usually a parent-child relationship as a parent has a duty to care for young people (Gibbins and Proctor 1918). However, a duty can also exist the opposite way around, where a grown up child is looking after their elderly parent.

  3. A duty which has been undertaken voluntarily: In the above case of (Gibbins and Proctor 1918) the partner had voluntarily undertaken to look after the girl. She therefore had a duty towards the child. When she failed to feed the child, she was guilty of murder because of that omission. Another example is Stone and Dobinson 1977 where the failure to help or summon medical help from other sources meant that they were breaching their duty. A more recent case where a mother was guilty of manslaughter through her failure to act is Evans 2009. D created a state of affairs which she knew was threatening the life of V.

  4. A duty through creating a dangerous situation: this is the concept of owing a duty and being liable through through omission was created in the case of Miller 1983 where a squatter accidentally set fire to his mattress. Also it was not the setting of his mattress on fire which made him guilty. Instead it was the fact that he failed to take reasonable steps to deal with the fire, as explained by the HoL. Another case where D knew that there were a dangerous situation but failed to take any steps is Santa-Bermudez 2003. His failure to tell the police officer of the needle made him guilty under s47 Offences Against the Person Act 1861 and was convicted of ABH (assault).

  5. A duty through one's official position: this is very rare but did happen in Dytham 1977. Because he was a police officer, he was guilty of wilfully and without reasonable excuse neglecting to perform his duty.

Involuntary manslaughter and omissions?

Involuntary manslaughter can be committed in two different ways:

  • unlawful act manslaughter

  • gross negligence manslaughter

Unlawful act manslaughter cannot be committed by an omission. There must be an 'act'. This was decided in Lowe 1973. However gross negligence manslaughter can be committed by an omission. It could be argued that Lowe should have been convicted because he owed the child a duty of care and he failed to get help (Stone and Dobinson 1977).

Duty of doctors? There can be cases where doctors decide to stop treating a patient. If this discontinuance of treatment is in the best interests of the patient then it is not an omission that can form the AR. This was decided in Airedale NHS Trust v Bland 1993. There, the court ruled that the doctors could stop artificially feeding Bland even though it was known that he could die as a result. This was held to be in his best interests.


Actus reus? This phrase is not an accurate description of conduct which will be sufficient to make a person liable for an offence. AR actually means 'act' yet the law clearly recognises that a failure to act can be sufficient for liability. The LC in its Draft Criminal Code 1989 preferred the phrase 'external element'.

Good Samaritan Law? Many countries have a law that places people under a duty to act. There are objections to this law since ordinary people should not be forced into acting like rescuers. In a developed country, the state provides well-trained and well-equipped professionals such as the police and ambulance crews to deal with emergency situations. These services are paid for through taxes, so it can be argued that every tax payer is already helping and doing their bit.

Problems when deciding if a duty exists? Its not completely sure when a duty of care exists. The normal way of deciding is:

  1. by the judge at the trial determining whether there is evidence capable of establishing a duty in law

  2. the jury then decides if the duty exists

  3. finally the jury decides if this duty has been broken.

The point that the law is capable of expanding to include new duty of care situations was stressed in Khan and Khan 1998 when the CoA stated in obiter that duty situations could be extended. However, this could be argued makes the law uncertain.

Assuming a duty? It can seem harsh that someone who accepts an adult into their home can be held to have assumed a duty towards that adult (Stone and Dobinson). An adult is normally held responsible for their own life. If an adult is vulnerable then the argument for imposing a duty is that the person assuming the duty is in the best position to ensure that potential harm is avoided. They will know the vulnerability of V when others do not. Also how do they discharge their duty??

Medical treatment? Even though by withdrawing feeding from an unconscious patient the medical staff are aware that this will cause the patient to die, they are not liable for that omission. They key issue being that such a failure to feed has to be in the patient's best interests. However, the Ho in Bland emphasised that euthanasia by a positive act would remain unlawful.

Statutory duties? Statutes impose duties in a wide variety of situations and make it an offence to fail to do something. Laws in this area often also impose SL. This means that not only D is liable because of his omission, but the prosecution do not have to prove he had MR. The justification for this is the greater good of society. Some of that statutory duties have been imposed because of the difficulty of proving an offence. This was the reason for the introduction of the offence of allowing the death of a child or vulnerable adult under the Domestic Violence, Crime and Victims Act 2004 (if both mother and father blame each other on the abuse of a child both will be liable). Under the 2004 Act all members of the household are liable for failing to protect the child/vulnerable adult.


Factual causation? D can only be guilty id the consequence would not have happened 'but for' D's conduct. This test can be seen in operation in Pagett 1983. he was guilty because the girl would not have died 'but for' him using her as a shield in the shoot out. The opposite situation can be seen in White 1910 where D tried to poison his mother but she died of a heart attack just before she drank it. D was not the factual causation of death, so he was guilty of attempted murder instead.

Legal cause? There may be more than one act contributing to the consequence. The rule is that D can be guilty if his conduct was more than a 'minimal cause' of the consequence. BUT D's conduct need not be a substantial cause. In Kimsey 1996 CoA held that instead of using the Latin phrase 'de minimis' it was acceptable to tell the jury it must be 'more than a slight or trifling link'. There may be more than one person whose act contributed to the death. D can be guilty even though his conduct was not the only cause of death. In Kimsey both drivers were driving at high speed but the one driver can be found guilty.

The 'thin-skull' rule: D must take the victim as they find them. It means that if V has something unusual about his mental or physical state, D will be liable for the more serious injury. Blaue 1975 is an example where the victim was a Jehovah's witness and this made her wound fatal. However D was still guilty because he had to take his victim as he found her.

Intervening acts? There must be a direct act link from D's conduct to the consequence. This is known as the chain of causation. In some situations something else happens after D's conduct, and if this is sufficiently separate from D's actions or omissions it may break the chain of causation. The chain of causation can be broken by:

  • an act of a third party

  • the victim's act

  • a natural but unpredictable event

The intervening act must be sufficiently independent and serious to break the chain of causation and remove D's liability.

Medical treatment

Medical treatment is unlikely to break chain of causation unless it is so independent that D's acts are insignificant.

    • Smith 1959: the treatment he was given was bad and might have affected his chances of recovery his chances of recovery, but the original wound was operating and substantial cause at the time of death. The death can be said to be a result of the wound albeit that some other cause is also operating.

    • Cheshire 1991: his conviction was upheld despite the fact that the wounds were not the operating cause of death. Intervening medical treatment can only be regarded as excluding responsibility of D if it was so independent of D's acts and so potent in causing the death, that the jury must regard D's acts as insignificant. Since D stop V his acts could not be seen as insignificant.

    • Jordan: victim died of the medical treatment, so D was not liable for the offence.

In the first two cases the doctors were carrying out treatments for the injuries in an attempt to save D's life. V would not have needed those treatments if they had not been seriously injured by D. In such situations the attacker is still liable even through the medical treatment was not good. In the 3rd case, the fact that V was given a large amount of a drug when the doctors knew he was allergic to it was a sufficiently independent act to break chain of causation.

Life-support machines: switching off a life-support machine by a doctor when it's been decided that V is brain dead does not break the chain of causation and this was decided in Malcherek 1981.

Victim's own act

If D causes V to react in a foreseeable way, then the only injury to the victim will be considered to have been caused by D.

    • Roberts 1971: girl jumped from car to to escape from D's sexual advances, so D was held liable for her injuries

    • Marjoram 2000: V jumped out of hostel window as D was shouting abuse and kicking the door. D's conviction of GBH was upheld as it was reasonably foreseeable that V would fear that the group would use violence

Unreasonable reaction: If V's reaction is unreasonable, then this may break the chain of causation. In Williams 1992 a hitch hiker jumped out of a car and died as D tried to steal his wallet. The CoA held that V's act needs to be foreseeable and in proportion to the threat. This makes it necessary to consider the surrounding circumstances in deciding whether chain of causation's conduct has broken the chain of causation. Where the threats to V are not so serious and V takes drastic action, it is more likely that the courts will hold that it broke the chain of causation.


Slight and trifling link? What is meant by 'more than a slight and trifling link'? This is vague and very difficult to define. As a result it could lead to juries applying different standards in different cases.

Taking your victim as you find them? Where V has a medical condition where it makes the injuries more serious, should D be liable for the more serious injury? It can be seen as being unjust where D does not know about the medical condition.

V refusing treatment? Should D be liable when V refuses medical treatment? This was probably justified when medical treatments were very primitive, especially when operations were carried out without anaesthetic (Holland 1841). However in Blaue 1975 V refused to receive a blood transfusion because of her religious beliefs. Her life could have been saves had she had the transfusion. It can be argued that D should not be liable for her death. He could have been charged with intent to do so (s18 OAPA 1961). This offence has a max penalty of a life imprisonment, so a suitable punishment should have been imposed on D. On the other hand, it is clear that the stab wound was the cause of V's death, so on this basis it should be argued that he should be liable for her death. Another case to illustrate this is Dear 1996 where D cut V numerous of times but she worsened the wounds in an attempt for suicide. Since the wounds were operating/significant cause, the jury was entitled to convict D.

Negligent medical help? In Smith 1959 the court used the test 'operating and substantial cause'. However the test might not have led to a conviction in Cheshire 1991. There V's wounds were virtually healed, yet V would not have had to have a tracheotomy if he had not been shot by D. So, the medical negligence in failing to notice the complications from the tracheotomy was not 'independent' of D's acts. They were a significant factor in V's death. The test developed in Cheshire was more suited to the situations in that case.


Smith E


A fairly comprehensive summary of the key cases on actus reus, that would suit those who are happy to revise from a text-heavy material. The use of bullet points makes the material easy to memorise. The Domestic Violence, Crime and Victims Act 2004 is a neat addition to the statutory duty section (very often, the Road Traffic Act 1988 is cited).



Very nice!



Very useful thanks!



Clear description of Actus Reus with a variety of relevant cases to support each point.