Actus Reus
‘Actus non facit reum nisi mens sit rea’
An act does not make someone guilty unless the mind is also guilty.
Actus reus = guilty act.
Establishing liability is not complete until defences are considered, even when actus reus and mens
rea are present.
An actus reus can be an act or an omission to act.
Voluntary Acts
A voluntary act is a positive act (not an omission), where free-will is in operation.
If D has moved their limbs, we are looking at a voluntary action - Bratty v A-G for Northern Ireland
[1963] AC 386.
However, there can be cases where D is doing a positive act, but not voluntarily. D will not be a
responsible agent in these involuntary circumstances…
Hill v Baxter [1958] 1 QQB 277 - D will not be liable where she is acting as an automaton.
➔ Automatism is where someone is not in control of their actions. e.g. D attacked by a swarm of
bees, flailing around trying to escape.
➔ D would not be in control of their limbs in this situation, the movement of D’s limbs would
involuntary as D was not exercising free will.
➔ Automatism is sometimes seen as a defence in criminal law, as it is a denial of the actus reus –
no voluntary act.
Winzar v Chief Constable of Kent (1983) - Being found drunk is a ‘state of affairs’, not a voluntary act.
Therefore, the possibility of being liable for the actus reus of an offence in this way, seems wrong.
Nevertheless, D can be found liable for a crime when s/he is drunk.
Misuse of Drugs Act 1971, s.5(2) - It is an offence for D to have a controlled drug in their possession.
Distinguishing between acts and omissions
Fagan v Metropolitan Police Commissioner [1969] 1 QB 439 - Both the actus reus and the mens rea
must be present at the same time for a crime to be committed. However, the mens rea does not have to
be present throughout the whole act/omission; it may be at the beginning or at the end.
➔ In the Fagan case, the mens rea was developed at the end.
Airedale NHS Trust v. Bland [1993] AC 789 - Distinguished between ending someone’s life in persistent
vegetative state (PVS), via a positive act like a lethal injection and the discontinuation of a treatment
already set up, which puts them back in their original position.
, ➔ This case established that life sustaining treatment could be discontinued and this would
not be murder, but an omission to act, as the doctors let nature take its course.
➔ If an interloper had come in and switched the machine off, this would be an act.
Omissions
General rule: There is no liability for an omission to act.
However, there are exceptions to this general rule for omissions to act:
EXCEPTION 1: Statutory / Contractual Duty to Act - this is where a pre-existing duty to act has been
created through statute.
➔ S.6 Road Traffic Act 1988 - A driver who fails to provide a sample of breath when
required to do so by a constable under specific circumstances will be committing a
criminal offence.
★ This is an example of a statutory duty.
➔ R v Pittwood (1902) 19 TLR 37 - D, a gatekeeper for a railway line, forgot to shut the
barrier. This resulted in a hay cart getting struck by a train, whilst crossing the railway
line. This killed the train driver. D had a positive duty to act based on his contract of
employment, which involved opening and closing the gates. The omission to close the
barrier brings criminal liability.
★ This is an example of a contractual duty.
EXCEPTION 2: Nature of the Relationship - a duty to act can arise from the nature of the relationship
between D and V.
R v. Gibbins and Proctor (1918) 13 Cr App R 134 - Gibbins and Proctor had failed to feed their child
(X). X died. The court said that they were guilty of X’s murder by withholding food. They had a duty to act
to provide food, and omitted to do so. They were liable for the murder of the child because the court was
satisfied that they had the mens rea for murder. The duty of care was based on the relationship
between parent and child.
➔ A parent’s duty to their child stops when the child reaches the age of majority (18
years old) - R v Sheppard (1862) Le & Ca 147.
R v Hood [2003] EWCA Crim 2772 - It is generally assumed that spouses, civil partners and
long-term partners have a duty to assist each other if they are in peril.
R v Smith (1826) 172 ER 203 - Siblings do not owe duty to act for each other.
➔ R v Evans [2009] EWCA Crim 650 - This lack of duty between siblings extends to step
siblings.
R v Adomako [1995] 1 A.C. 171 - Doctors owe a duty to act in relation to their patients.
‘Actus non facit reum nisi mens sit rea’
An act does not make someone guilty unless the mind is also guilty.
Actus reus = guilty act.
Establishing liability is not complete until defences are considered, even when actus reus and mens
rea are present.
An actus reus can be an act or an omission to act.
Voluntary Acts
A voluntary act is a positive act (not an omission), where free-will is in operation.
If D has moved their limbs, we are looking at a voluntary action - Bratty v A-G for Northern Ireland
[1963] AC 386.
However, there can be cases where D is doing a positive act, but not voluntarily. D will not be a
responsible agent in these involuntary circumstances…
Hill v Baxter [1958] 1 QQB 277 - D will not be liable where she is acting as an automaton.
➔ Automatism is where someone is not in control of their actions. e.g. D attacked by a swarm of
bees, flailing around trying to escape.
➔ D would not be in control of their limbs in this situation, the movement of D’s limbs would
involuntary as D was not exercising free will.
➔ Automatism is sometimes seen as a defence in criminal law, as it is a denial of the actus reus –
no voluntary act.
Winzar v Chief Constable of Kent (1983) - Being found drunk is a ‘state of affairs’, not a voluntary act.
Therefore, the possibility of being liable for the actus reus of an offence in this way, seems wrong.
Nevertheless, D can be found liable for a crime when s/he is drunk.
Misuse of Drugs Act 1971, s.5(2) - It is an offence for D to have a controlled drug in their possession.
Distinguishing between acts and omissions
Fagan v Metropolitan Police Commissioner [1969] 1 QB 439 - Both the actus reus and the mens rea
must be present at the same time for a crime to be committed. However, the mens rea does not have to
be present throughout the whole act/omission; it may be at the beginning or at the end.
➔ In the Fagan case, the mens rea was developed at the end.
Airedale NHS Trust v. Bland [1993] AC 789 - Distinguished between ending someone’s life in persistent
vegetative state (PVS), via a positive act like a lethal injection and the discontinuation of a treatment
already set up, which puts them back in their original position.
, ➔ This case established that life sustaining treatment could be discontinued and this would
not be murder, but an omission to act, as the doctors let nature take its course.
➔ If an interloper had come in and switched the machine off, this would be an act.
Omissions
General rule: There is no liability for an omission to act.
However, there are exceptions to this general rule for omissions to act:
EXCEPTION 1: Statutory / Contractual Duty to Act - this is where a pre-existing duty to act has been
created through statute.
➔ S.6 Road Traffic Act 1988 - A driver who fails to provide a sample of breath when
required to do so by a constable under specific circumstances will be committing a
criminal offence.
★ This is an example of a statutory duty.
➔ R v Pittwood (1902) 19 TLR 37 - D, a gatekeeper for a railway line, forgot to shut the
barrier. This resulted in a hay cart getting struck by a train, whilst crossing the railway
line. This killed the train driver. D had a positive duty to act based on his contract of
employment, which involved opening and closing the gates. The omission to close the
barrier brings criminal liability.
★ This is an example of a contractual duty.
EXCEPTION 2: Nature of the Relationship - a duty to act can arise from the nature of the relationship
between D and V.
R v. Gibbins and Proctor (1918) 13 Cr App R 134 - Gibbins and Proctor had failed to feed their child
(X). X died. The court said that they were guilty of X’s murder by withholding food. They had a duty to act
to provide food, and omitted to do so. They were liable for the murder of the child because the court was
satisfied that they had the mens rea for murder. The duty of care was based on the relationship
between parent and child.
➔ A parent’s duty to their child stops when the child reaches the age of majority (18
years old) - R v Sheppard (1862) Le & Ca 147.
R v Hood [2003] EWCA Crim 2772 - It is generally assumed that spouses, civil partners and
long-term partners have a duty to assist each other if they are in peril.
R v Smith (1826) 172 ER 203 - Siblings do not owe duty to act for each other.
➔ R v Evans [2009] EWCA Crim 650 - This lack of duty between siblings extends to step
siblings.
R v Adomako [1995] 1 A.C. 171 - Doctors owe a duty to act in relation to their patients.
