INTRODUCTION TO ACTUS REUS
AND
OMISSIONS
Basic Reading
Herring, Chapter 2 and at least one other textbook chapter on Actus Reus
Further Reading
A. Ashworth & E. Steiner, ‘Criminal Omissions and public duties: the French
Experience’(1990) 10 Legal Studies 153
A. Ashworth, ‘The Scope of Criminal Liability for Omissions’ (1989) 105 LQR 424
A. Ashworth, ‘Manslaughter by Omission and the Rule of Law’ [2015] Crim LR 563
N. Cobb, ‘Compulsory Care-Giving: Some Thoughts on Relational Feminism, the Ethics of
Care and Omissions Liability’ (2008) 39 Cambrian Law Review 11
A. McGee, ‘Ending the life of the Act/Omission Dispute: Causation in Withholding and
Withdrawing Life-Sustaining Measures’ (2011) 31 Legal Studies 478
A. Simester, ‘Why Omissions are Special’ (1995) 1 Legal Theory 311
G. Williams, ‘Criminal Omissions – the Conventional View’ (1991) 107 LQR 86
The Component Elements of a Crime
Think of the component elements that make up criminal liability as an equation.
Actus Reus + Mens Rea = Criminal Liability
For most offences, you need to establish the actus reus which is the conduct element (e.g.
for murder, causing the death of a person) and the mens rea which is the mental element
(e.g. for murder, intending to kill or cause GBH).
If these components of an offence are established, you must then consider if there is a valid
defence available to the defendant (e.g. self-defence).
Definition of Actus Reus:
The actus reus of an offence comprises all the external elements of the definition of the
offence. It may include
conduct (acts or omissions),
consequences caused by the conduct,
and surrounding circumstances/state of affairs
NB – The Actus Reus of every crime is different
1
, The Actus Reus Must be Proved
If D has the Mens Rea for a crime but does not bring about the Actus Reus he is not guilty of
committing that offence.
R v Deller [1952] 23 Cr App R 184
The Act must be Voluntary
Where the Actus Reus of an offence requires conduct on the part of the accused liability will
only accrue where the conduct is voluntary.
In Bratty v AG for Northern Ireland [1963] AC 386 (HL) Lord Denning stated that
‘The requirement that it should be a voluntary act is essential…in every criminal case. …
R v Quick [1973] 3 WLR 26 (CA)
Leicester v Pearson [1952] 2 All ER 71
Situational/State of Affairs cases – An Exception to the Voluntary Rule?
R v Larsonneur (1933) 24 Cr App Rep 74
Winzar v Chief Constable of Kent (1983) Times 28 March
Omissions
The habit of lawyers of referring to the "actus reus”, suggestive as it is of action rather than
inaction, is no doubt responsible for any erroneous notion that failure to act cannot give rise
to criminal liability in English law – per Lord Diplock in Miller [1983] 2 AC 161
2
AND
OMISSIONS
Basic Reading
Herring, Chapter 2 and at least one other textbook chapter on Actus Reus
Further Reading
A. Ashworth & E. Steiner, ‘Criminal Omissions and public duties: the French
Experience’(1990) 10 Legal Studies 153
A. Ashworth, ‘The Scope of Criminal Liability for Omissions’ (1989) 105 LQR 424
A. Ashworth, ‘Manslaughter by Omission and the Rule of Law’ [2015] Crim LR 563
N. Cobb, ‘Compulsory Care-Giving: Some Thoughts on Relational Feminism, the Ethics of
Care and Omissions Liability’ (2008) 39 Cambrian Law Review 11
A. McGee, ‘Ending the life of the Act/Omission Dispute: Causation in Withholding and
Withdrawing Life-Sustaining Measures’ (2011) 31 Legal Studies 478
A. Simester, ‘Why Omissions are Special’ (1995) 1 Legal Theory 311
G. Williams, ‘Criminal Omissions – the Conventional View’ (1991) 107 LQR 86
The Component Elements of a Crime
Think of the component elements that make up criminal liability as an equation.
Actus Reus + Mens Rea = Criminal Liability
For most offences, you need to establish the actus reus which is the conduct element (e.g.
for murder, causing the death of a person) and the mens rea which is the mental element
(e.g. for murder, intending to kill or cause GBH).
If these components of an offence are established, you must then consider if there is a valid
defence available to the defendant (e.g. self-defence).
Definition of Actus Reus:
The actus reus of an offence comprises all the external elements of the definition of the
offence. It may include
conduct (acts or omissions),
consequences caused by the conduct,
and surrounding circumstances/state of affairs
NB – The Actus Reus of every crime is different
1
, The Actus Reus Must be Proved
If D has the Mens Rea for a crime but does not bring about the Actus Reus he is not guilty of
committing that offence.
R v Deller [1952] 23 Cr App R 184
The Act must be Voluntary
Where the Actus Reus of an offence requires conduct on the part of the accused liability will
only accrue where the conduct is voluntary.
In Bratty v AG for Northern Ireland [1963] AC 386 (HL) Lord Denning stated that
‘The requirement that it should be a voluntary act is essential…in every criminal case. …
R v Quick [1973] 3 WLR 26 (CA)
Leicester v Pearson [1952] 2 All ER 71
Situational/State of Affairs cases – An Exception to the Voluntary Rule?
R v Larsonneur (1933) 24 Cr App Rep 74
Winzar v Chief Constable of Kent (1983) Times 28 March
Omissions
The habit of lawyers of referring to the "actus reus”, suggestive as it is of action rather than
inaction, is no doubt responsible for any erroneous notion that failure to act cannot give rise
to criminal liability in English law – per Lord Diplock in Miller [1983] 2 AC 161
2
