Introduction to Criminal Law
2022
LPU 301: Criminal Law I*
2021/2022 Session
Introduction and Definition of Crime
Criminal law is the branch of public law which is concerned with proscribing behaviour or
conduct which offends the acceptable standard within a society in the interest of the public.
Criminal law is different and distinct from other areas of law such as the law of tort or law of
contract which deal with private interests that affect individuals solely. Criminal law is
unique in nature as it primarily involves the State as against individuals. Criminal law
encompasses both the substantive and procedural aspects of proscribing and punishing
behaviour within a society. Simply put, criminal law is the law relating to crimes.
Literally, crime is a generic name for a wide range of conducts, which are considered morally
reprehensible and socially unacceptable in a society. However, it is likely for certain conducts
to be anti-social but do not fall within the category of what constitute a crime in legal
parlance. Thus, it is apposite to define what a crime is, in order to understand the scope and
ambit of the subject and distinguish it from the general perception. The concept of crime just
like most legal concepts, has no single comprehensive meaning as there are varied and
numerous definitions of crime.
Allen defines crime as ‘a human conduct which the State decides to prevent by threat of
punishment, liability of which is determined by legal proceedings of a special kind’
Earl Jowitt defines crime as ‘an act or default, which tends to the prejudice of the community
and is forbidden by law on pain or punishment inflicted at the instance of the state’
Carrara states that a ‘crime is not an entity in fact but an entity in law, it is not action but
infraction’
Halsbury describes crime as ‘an unlawful act or default, which is an offence against the
public and render the person guilty of the act or the default liable to legal punishment’
Prof. Kenny states that crimes are ‘wrongs whose sanction is punitive and is in no way
remissible by any private person but remissible by the crown alone if remissible at all.’
Okonkwo and Naish define crime as those breaches of law resulting in special procedure
controlled by the state and liable to sanction over and above compensation and costs.
Sec. 2 of the Criminal Code (CC) defines crime as an ‘act or omission, which renders the
person doing the act or making the omission liable to punishment under this code, or under
any Act or Law’
In the same vein, there are definitions offered by other authors and learned jurists such as
Glanville Williams, Stevens, Blackstone, Clark, Lord Atkin etc. Certain features stand out
from the various definitions;
*
This summary is specifically designed as a reading guide to LPU 301 students and it is by no means exhaustive
on the topic.
LPU 301
Faculty of Law, University of Ibadan
1
Introduction to Criminal Law
2022
First, a crime is punishable at the instance of the state. Another feature is that a crime may not
necessarily be an act but could also be inaction or omission. In addition, it appears that
definitions attempt to describe what constitute crime rather than define it. Thus, the various
definitions of a crime are based on the content or substance of criminal behaviour or in terms
of the applicable legal procedure as against civil wrongs. While it is possible for a single
cause of action to give rise to both civil and criminal proceedings, a crime is distinguishable
from a tort or any other form of civil wrongs. Where a single cause of action gives rise to
both civil and criminal proceedings, the criminal proceedings may run simultaneously with
the civil action. See the provision of s. 320 (2) of the Administration of Criminal Justice Act
2015.
In Nigeria where the accusatorial/adversarial system is operative, there are certain notable
features of the criminal justice system. First, there is a presumption of innocence in favour of
the accused person. Thus, during trial the accused is not burdened to establish his innocence,
rather the prosecution bears the evidential and legal burden of establishing the accused’s
guilt. See s.36 (5) of the Constitution of the Federal Republic of Nigeria (CFRN) 1999 (As
Amended). Criminal trials are undertaken by the State against the Defendant (accused) since
crimes are regarded as public wrong. The nomenclature of the parties at different levels in
each case is determined by the nature of the offence and the authorised prosecuting authority.
The State is the complainant while the victim, at best, is a witness (i.e. principal witness).
This also implies that it is only the State that may discontinue criminal proceedings (Nolle
Prosequi), see ss.174 and 211 of the CFRN 1999. This however does not preclude private
prosecution of criminal offences in certain circumstances once the necessary fiat has been
obtained as provided by ss. 109 (e) and 383-384 of the ACJA 2015. See the cases of Akinlu v
Fawehinmi (1989) 3 NLR pt112 685, 738 and; FRN v Sen. Olawole Julius Adewunmi (2007)
10 NWLR (pt.1042) 399. In practice however, private prosecution of criminal cases is rare. In
a civil matter, the Claimant is at liberty to withdraw his case against the Defendant at any
stage of the proceedings. The court is in fact, inclined to encourage out of court settlement or
private settlement through alternative dispute resolution (ADR). Whereas in criminal trials,
private settlement is a rare feature except in few cases such as compounding which is only
applicable to certain offences. See. s.127 CC. Where the principal witness (in most cases the
victim, except where such is deceased), indicates lack of interest in the prosecution of the
case, it may be brought to the notice of the court by the prosecutor and the court reserves the
discretion to strike out the case against the accused.
Another notable feature in criminal trials is the standard of proof, which is beyond reasonable
doubt. The legal burden is on the prosecution to establish the guilt of the accused in respect of
the particular crime with which he has been charged, beyond all reasonable doubt, the legal
burden never shifts. Where the accused raises a particular fact in his defence or as a plea, the
evidential burden is on the accused to establish such on the preponderance of evidence but
the legal burden remains on the prosecution. Where the prosecution fails to discharge this
burden in any criminal trial, the accused may be discharged and acquitted. In addition, in
criminal trials, punishment is imposed in form of fine, imprisonment or death penalty.
Overall, there are other features of criminal trials, which distinguish them from civil
proceedings, and the list may appear endless.
LPU 301
Faculty of Law, University of Ibadan
2
Introduction to Criminal Law
2022
Purpose of Criminal Law
The American Model Penal Code identified one of the general purposes of criminal law as: to
forbid and prevent conduct that unjustifiably and inexcusably inflicts or threatens substantial
harm to individual or public interest. Wilson states that the concerns of criminal law may be
expressed in two respects; public interest and private interest. With regards to public interest,
criminal law:
i.
prevents physical injury to person or damage to property by proscribing such acts as
murder, manslaughter, arson;
ii.
protects public morality by proscribing personal immorality deemed to be injurious to
society’s well-being, this accounts for such offences as bigamy, incest, drug
possession;
iii.
maintains the integrity of the state and administration of justice through offences such
as treason, perjury, sedition;
iv.
maintains public order and security by proscribing such acts as riot, affray, breach of
public peace and;
v.
provides sufficient safeguard against the exploitation and corruption of the most
vulnerable member of the society such as the young, inexperienced or weak in mind.
In relation to private interests, criminal operates to:
i.
ensure the protection and freedom of individuals from undesired physical interference
through crimes such as rape, assault;
ii.
safeguard individual property against undesired interference through offences such as
stealing, robbery, burglary.
History of Criminal Law in Nigeria
The history of Nigerian criminal law can be traced to the pre-colonial era. For historical
purpose, three different periods are significant: the pre-colonial era when the
customary/traditional criminal law system was operative; the colonial period which ushered
the introduction of formal and common law criminal justice system and independence/postindependence period. Before the advent of the British colonial rule in Nigeria, various
communities in different locations on the territory which presently make up Nigeria had
traditional criminal justice system in place. Some of the notable kingdoms such as the Benin
kingdom, the Borno empire, the old Oyo kingdom had established traditional justice systems
in various communities constituting these kingdoms. These communities operated a simple
social justice system with established social norms. The social justice system proscribed both
civil wrongs and acts which are regarded as criminal. The system operated through various
units such as the family, village, group of villages, towns and cities which make up the
kingdom. Thus, there were native laws and customs proscribing certain acts as criminal
though largely unwritten especially in the Southern region as opposed to the Northern part
which operated a Sharia system based on the Islamic law alongside indigenous criminal law.
LPU 301
Faculty of Law, University of Ibadan
3
Introduction to Criminal Law
2022
Following the conquest of many parts of the North by Usamn Dan fodio, an Islamic scholar
and devout Muslim, a caliphate was established in the North with its headquarters in Sokoto.
With the established of the northern caliphate, Sharia law became established and
administered as the operative law in the North. There were different applicable schools of
thought of the Sharia law, prominent among which were the Maliki, Surfi and Surni schools
of thought with identified differences among them. Thus, Sharia law and the traditional
criminal law was applicable in the North especially among the Kanuris and Nupes. Islamic
laws were administered by the Alkalis (learned Islamic jurist who were well-versed in
Islamic law) in specialised local courts in the Northern region.
The advent of the British colonial government and the subsequent introduction of English
common law to the Lagos colony in 1863 did not, at first, alter much of the existing criminal
justice system in various communities outside the Lagos colony. However, specific conducts
such as slave dealing, witchcraft, trial by ordeal and other offences were outlawed in places
outside Lagos colony. By the spread of the English administration in Nigeria, it became
expedient to have a specific, worded and unified set of criminal principles which would be
applied by the British courts already established in the whole realm of Nigeria. In 1904, Lord
Lugard introduced by proclamation, a Criminal Code in the Northern region to consolidate
and amend the criminal law in the country. Following the amalgamation of the protectorates
and colony in 1914, the Code became applicable to the whole country in 1916. The Criminal
Code Ordinance was modelled after the Queensland Code 1899 of Australia. This would
account for the reason references were made to cases from the jurisdiction in later Nigerian
criminal law cases, although such cases were merely persuasive in nature and not binding on
Nigerian courts. The Code itself had been an English draft criminal code authored by Sir
James Fitzstephen in 1878 proposed to replace the English common law but was never
adopted. It then became a prototype criminal code adopted for several of the English
colonies.
In the North, the application of the Criminal Code Ordinance was at first strictly limited
because the Islamic criminal law (Sharia) was made applicable in most cases involving
people within the area and s.4 of the proclamation expressly exempted its application in
native courts. However, the problem of conflict of laws arose as most aspects of Maliki laws
for instance were not acceptable to those trained in English law. For instance, the Maliki law
provided for the offence of homicide punishable by death which included any hostile,
unjustified assault resulting in death, even though unintended or extremely unlikely. The
most frequent friction was that which was caused by the concept of provocation which is
recognised as a mitigating factor and capable of reducing murder to manslaughter in English
law was not recognised in Maliki law. The intensity of the conflict was marked by the fact
that the Maliki law had been integrated into the Northern Muslim way of life and the British
colonial government was reluctant to undermine its authority in the North thus the
introduction of the Criminal Code was gradual unlike in the Southern part of the country. In
1933, an attempt to abolish customary criminal law was largely unsuccessful but a step was
taken towards that direction through amendment of s.4 of the Criminal Code Ordinance. S.4
of the Criminal Code Ordinance provided that no person could be tried or punished in any
court for an offence except under the express provisions of the Code or other written law.
LPU 301
Faculty of Law, University of Ibadan
4
Introduction to Criminal Law
2022
However, the Native Courts Ordinance in s.10 (1) and (2) allowed native courts to administer
native law and customs subject to various provisos on the humanity of the punishment
imposed on the offender. The amendment became a subject of controversy in Gubba v
Gwandu Native Authority (1947) 12 WACA 141 and the court held that where a native court
tried an offence in accordance with native law and custom, it could impose the customary
penalty subject to the provisos in the Code. However, where such offence could be tried
under both laws, the Court must apply the Criminal Code. The decision however seemed to
have sparked off more controversies. Thus, while the Code existed alongside customary
criminal laws in various part of the country the conflict persisted. In 1957, the correct
position was settled in the case of Maizabo v Sokoto Native Authority (1957) NRNLR 133
where the court held that native or customary courts were empowered to apply customary
criminal law, even if there was a provision on the subject in the Criminal Code but the court
must not pass sentence in excess of the maximum imposable if the case had been tried under
the Criminal Code.
Owing to the dual nature of the criminal justice system and the need to settle the conflict
between the two systems in the northern region coupled with the movement for the reform of
the Maliki criminal law, a panel was established. A panel of jurists led by Prof. Anderson was
established in 1958 to examine the relationship between the two systems and create a code
that would be naturally acceptable by the Northern communities. The panel came up with
recommendations that the Maliki law should be applied to the personal and family life of
Muslim litigants and the substantive and procedural aspects of criminal law should be
codified. In 1959, the Penal Code emerged to displace the Criminal Code and made
applicable in the North. The Penal Code was modelled after the Sudanese Code which had
been in operation in Sudan, a predominantly Muslim community. The Sudanese Code was
equally modelled after the Indian Penal Code of 1890. The Indian Code itself had been an
adaptation of an earlier draft of English Criminal Code by Lord Macaulay. It is important to
note that the provisions of the Penal Code differ substantially from that of the English
Criminal Code but similar in few instances. The Code permitted provocation as mitigation of
punishment in homicide cases but reserved traditional Muslim offences such as drinking
alcohol, adultery, insult to the modesty of a woman, fornication etc. Specific serious offences
such as treason, sedition, offences relating to custom etc. were reserved and treated as
addendum to the Penal Code. Thus, the Penal Code can be described as a compromise
between the English criminal law and Islamic penal law.
Following the decision at the constitutional conference of 1958 to abolish customary criminal
law, the Bill of Rights of 1959, s.22(10) of the independence constitution of 1960 and 1963
constitution provided that ‘no person shall be convicted of a criminal offence unless that
offence is defined and the penalty therefor is prescribed in a written law.’ Similarly, this
provision is entrenched in s. 36 (12) of CFRN 1999. Hence, customary criminal law as well
as common law ceased to operate in Nigeria at independence. This provision is entrenched
expressly in s.3(2) of the Penal Code. At independence, traditional/customary offences were
preserved only in so far as they are codified in a written law. Since independence, the country
has operated a dual criminal code system with the Penal Code operating in Northern Nigeria
while the Criminal Code operated in the South. Each of the two Codes covers offences
LPU 301
Faculty of Law, University of Ibadan
5
Introduction to Criminal Law
2022
committed within the territory to which it applies and operates only within that territory.
Where a person commits an offence within a particular territory and escapes to another
territory. He cannot be tried in that new territory because crime has no extra-territorial
application. Thus, a person cannot be tried for any offence in the South which does not exist
in the Criminal Code or any of its criminal laws. See. Aoko v Fagbemi (1961) 1 All NLR 400.
See also Udokwu v Onugha (1963) 7 ENLR 1. Note however that in respect of federal
offences, an accused person can be tried in any part of the federation irrespective of where
the offence was committed within the federation. Note also that there are certain international
crimes over which any country may exercise universal jurisdiction. Such crimes are regarded
as grave and serious crimes against the entire world and humanity in general hence they have
extra-territorial application. Such crimes include, war crimes, crimes against humanity and
genocide. See the provisions of the Rome Statute of the International Criminal Court 1998.
Applicable laws in Nigerian Criminal Law
The dual criminal code system makes the Criminal Code applicable in the Southern part
which includes all the 17 states of the southern part of the federation and Penal Code
applicable to 19 states of the Northern part of the federation. Subsequently, each of the states
within the federation domesticated/adapted the applicable codes within their territories. Apart
from the operation of the dual criminal code system, there are other laws, both state and
federal, which criminalise certain acts for which an accused person may be prosecuted. There
are other statutes which also make provisions for the procedural aspect of the criminal justice
system in Nigeria. Such laws include in addition to the laws and rules of various courts, the
Administration of Criminal Justice Act 2015 (and the equivalent laws in various states),†
Evidence Act 2011. Notable among the substantive laws are Money Laundering (Prohibition)
Act 2011, Advance Fee Fraud and Other Fraud Related Offences Act 2006, Economic and
Financial Crimes Commission (Establishment) Act 2002, Corrupt Practices and Allied
Offences Act 2000, Road Traffic Act 1961, Code of Conduct Bureau and Tribunal Act Cap C
15 LFN 2004, Robbery and Firearms (Special Provision) Act, Firearms Act, Terrorism
(Prevention) Act 2011 and subsequent Terrorism (Amendment) Act 2013. Cybercrimes
(Prohibition and Prevention) Act 2015 etc.
Law and Morals
Historically morals have played a significant role in shaping law especially considering the
influence of cannon law in shaping modern criminal law. The existence of laws criminalising
some outrageous acts such as murder, rape, stealing etc. in order to uphold certain public
morals shows that law and morals are interconnected. Morality has influenced law such that it
could be the rationale for criminalising some immoral acts (sexual offences such as
prostitution, homosexuality, incest, abortion) even though today it appears that morality is
fast losing its influence especially in criminal law. Immorality and criminality appear closely
related but are not synonymous. There are a number of morally reprehensible conducts which
†
Initially, the Criminal Procedure Code was made applicable in the North and the Criminal Procedure Act
applicable in the South (each of which has been adapted in the applicable states). However, with the
introduction of the Administration of Criminal Justice Act (ACJA) 2015 and subsequent domestication by some
states, the CPC or CPA has been outlawed in those states with Administration of Criminal Justice Law (ACJL).
LPU 301
Faculty of Law, University of Ibadan
6
Introduction to Criminal Law
2022
do not attract any penal sanctions, adultery, drunkenness, (except in some jurisdictions such
as is the case under the Penal Code applicable in northern Nigeria), indecent dressing,
disrespect for elders etc. In the same vein, certain conducts are morally neutral but may be
penalised e.g. some traffic offences such as over speeding, drunk driving etc.
There have been divergent views on the relationship between law and morals. Essentially
there are two divides:
Natural law theorist like St. Thomas Aquinas believe that law and morality are connected.
According to Aquinas, ‘A law without morality is not law…[but] perversion of law’ He
believed that law must appeal to morals otherwise there should be no obligation to obey it
According to Lord Denning ‘in order that an act should be punished, it must be morally
blame worthy. It must be a sin’
To Stephen J., ‘The alliance between criminal law and moral sentiments is in all ways
healthy and advantageous to the community. It is desirable that criminals should be hated’
For Lord Devlin, Blackstone and other natural law theorist, they believe the function of
criminal law is merely to enforce moral principles and nothing else.
Legal positivists on the other hand, are of the view that there should be a rigid separation
between law and morality.
Hans Kelson in his pure law theory opines that law must be totally devoid of morals. He
believes that law does not require any moral validation to be legitimate.
However, it is clear that that criminal law and morality are two separate but interrelated
concepts. As rightly observed by Lord Coleridge in the case of R v Dudley & Stephen (1884)
14 Q. B. D 273, ‘the absolute divorce of law from morality would be of fatal consequence’.
Thus, the debate has been: where should the dividing line be drawn between immorality and
criminality? Should an act be a crime simply on the grounds of its immoral objects? The
report of the Wolfenden Committee on Homosexual Offences and Prostitution published in
1957 becomes instructive for the purpose of the ongoing debate. Established because of the
increasing number of convicts of homosexual offences in England in 1954, the committee
recommended that ‘homosexual behaviour between two consenting adults in private should
no longer be a criminal offence’. The Committee opined that the enforcement of private
morality is not a proper subject of the criminal law. The Committee further reported that the
purpose of criminal law is to:
Preserve public order and decency, to protect citizens from what is offensive or
injurious and to provide sufficient safeguards against exploitation and corruption of
others particularly those that are specially vulnerable because they are they are
young weak in body or mind, inexperience or in a state of special, physical or
economic dependence
The Wolfenden report attracted several public debates and was subsequently challenged by
Lord Devlin. He attacked the notion that law should not concern itself with private morality.
LPU 301
Faculty of Law, University of Ibadan
7
Introduction to Criminal Law
2022
In his argument he posed three interrogatory questions on the role of morals in shaping the
law of a society:
a) Whether the society has the right to pass judgement on all matters of morality?
b) If the society has such right, does it also have the right to use the weapon of criminal
law to enforce its judgement?
c) Should the society use the weapon of criminal law only in all or some cases and on
what basis should each case be distinguished?
Devlin answered the first two questions in the affirmative and concluded that where a
particular practice has reached such a stage that the right-minded person in the society will
view such act with indignation, intolerance and disgust, then the society must use the weapon
of criminal law to enforce its judgment.
Prof. H. L. A. Hart disagreed with the view of Lord Devlin. He pointed out that immorality is
not the only criterion that a prudent law maker should consider in criminalising a particular
conduct. He posited that there are multiple criteria to consider in deciding whether or not to
criminalise an act. He noted that three criteria: HARM, ENFORCEABILITY and
PATERNALISM should be used.
Harm: Does the act/practice harm anybody?
Enforceability: Can the particular act be prohibited by law?
Paternalism: Can the society acting as ‘parens patriae’ enforce the prohibition of such act?
He concluded that where an act passes all the three tests in the affirmative, then it must be
criminalised and not necessarily if the act is morally reprehensible or not.
In the midst of these debates the House of Lords in the case of SHAW v DPP (1962) A.C 280
per Lord Simonds made the assertion that:
‘There remains in the court of law, residual power to enforce the supreme and
fundamental purpose of the law, to conserve, not only the safety and order but also,
the moral welfare of the state.
…. The King’s Bench is the custos mourn
(custodian/guardian of morals) of the people and had superintendency over offences
which are contra bonos mores it decorum (contrary to morals and decorum)’
Subsequently, the English Parliament in 1967 passed the Sexual Offences Act which
outlawed the Offences Against the Person Act of 1861 and the Labouchere Amendment of
1885 which decriminalised homosexual conduct between consenting adults and equally
enacted the Abortion Act of 1967. Thus, the English court delineated the relationship
between law and moral. See further the case of KNULLER v DPP (1972) 2 All ER 898
In Nigeria, certain provisions of the Criminal Code and Penal Code show that the Nigerian
criminal law is not devoid of moral influence. Ss. 214-233A, under Chapter 21, of the
Criminal Code provide for ‘Offences against Morality’. Under the Penal Code, ss. 387-388
criminalise adultery, alcoholism. On the other hand, controversies surrounding the passage of
laws such as the Same-Sex Marriage Prohibition Act and the rejection of morally influenced
LPU 301
Faculty of Law, University of Ibadan
8
Introduction to Criminal Law
2022
bills such as the Act against indecent Dressing Bill 2008 still leaves open, the debate on law
and morality. Also, the debates on criminalisation of corruption and corrupt practices reveal
that the debate on law and morals may be an ongoing, (perhaps endless) debate.
Overall, it should be noted that law is distinct from morals even though the two concepts are
not unconnected. So also, a crime is distinct from a moral wrong. Summarily below are the
notable points:
-Historical antecedents reveal that crimes are traditionally viewed as immoral acts deserving
sanctions. A crime may be morally reprehensible and as such morality could be the rationale
for criminalising an act hence, the connection between law and morals. Rules of morality
vary from society to society and this equally reflects in what constitute crimes from society to
society. However, while a crime may also be a moral wrong, not all moral wrongs are crimes.
This draws the distinction between ‘mala in se’ crimes and ‘mala prohibitia’
-Despite this variation, certain acts are ‘universal’ crimes regardless of their moral status and
the society. Thus, the interconnection between law and morals is severed by drawing a
distinction between public wrong and private morality. The distinction between public wrong
and private morality appears to be the basis of the debates on the distinction between law and
morals.
-Essentially, a crime is a public wrong proscribed by legal codification i.e. expressly written
down in a statute stating its substance and content and not necessarily moral or social
condemnation. See ss. 36 (8) and (12) of CFRN 1999 (As Amended) and s. 11 of the CC. See
also Article II par. 2 of the United Nations Universal Declaration of Human Rights 1948.
Elements of an Offence
Flowing from the definition of s.2 of the Criminal Code (CC), an offence is typically an act
or omission done in a particular proscribed state of mind. A look at the definition of most
offences in the CC reveals that they inevitably consist of two parts i.e. the physical and
mental elements. Such offence which have two parts are regarded as ‘true crimes’ as opposed
to ‘strict liability offences’. The physical element of a crime is referred to as the guilty act,
i.e. the overt act or conduct which the law proscribes expressed as ‘Actus Reus’ in Latin. The
mental element pertains the state of mind of the accused which is equally expressed as Mens
Rea in Latin. For instance, the offence of stealing consists of the physical act of ‘taking or
converting’ another property and the mental requirement of intent to fraudulently and
permanently deprive the owner of the property. Any trial involving the prosecution of true
crimes require the proof of both elements beyond reasonable doubt by the prosecution, this
rest on the general principle that a person is not criminally responsible for his conduct unless
he possesses the proscribed state of mind. This principle is expressed in the Latin maxim;
‘Actus non facit reum, nisi mens sit rea’ which literally means an act/conduct alone does not
make guilty unless the mind is legally blameworthy.
Physical Element - Actus Reus
Although there is no statutory definition of the ‘actus reus’ of a crime, the ‘actus reus’ of an
offence can be defined as all the material elements/ingredients/requirement in the definition
LPU 301
Faculty of Law, University of Ibadan
9
Introduction to Criminal Law
2022
of a crime/offence except the accused mental state. Material elements in this context excludes
matters relating to jurisdiction, procedure and other matters unconnected with the conduct
sought to be prevented by the law defining the offence.
Forms of Physical Element of a Crime – Actus Reus
The physical element of an offence could be in form of a conduct, circumstance/state of
affairs, result/consequences or an omission which the law proscribes. For instance, the
offence of murder proscribes a particular result, which is; death of the victim, perjury
proscribes a particular conduct which is; lying on oath, possession of narcotic drugs
proscribes a passive state of mere possession of narcotic substance etc. It is important to
prove the actus reus in each case since intention alone no matter how wicked/dangerous/evil
is not generally forbidden or punished. There are instances where the law may punish mere
intention such as in cases of inchoate offences or liability for participation in an offence. For
instance, where ‘Shylock enters ‘Antonio’s’ premises with the intention of stealing
‘Antonio’s car parked in the premises but upon entry, ‘Antonio’ eventually gives the car to
‘Shylock’ as a gift. ‘Shylock’ cannot be convicted of the offence of stealing. This is equally
based on the old English expression that the thoughts of a man are not triable for even the
devil himself does not know the thoughts of man.
Generally, the law does not punish failure to act and the ‘actus reus’ of a crime is usually
satisfied by positive acts in the forms recognised above. However, following the provisions
of s.2 CC, omissions may also constitute ‘actus reus’. For omission to constitute ‘actus reus’
there must be a duty to act imposed on the party concerned (accused/Defendant), a moral
duty alone will not suffice but a legal duty. E.g. the moral duty to rescue a drowning child
imposes no criminal liability. Such duty may be imposed:
-by statute or operation of law as in the case of s. 199 (suppression of riot by peace officers)
s.343 (negligent omissions) and such other offences relating to omissions as spelt out in
chapter 26 of CC
-by contract as in the case of R v Pittwood (1902) 19 TLR 37.
-by the existence of special relationships as in relationship between parents and their children,
husband and wife
-voluntary assumption of duty
-by the creation of a dangerous act. See the case of R v Miller (1983) 2 AC 16. James Miller
was a squatter in ‘p’ house, who became drunk and fell asleep with a lit cigarette in his hand.
He woke up and found the cigarette smouldering the mattress, he did nothing to put it out, but
he simply moved into an adjoining room to continue his sleep. The house caught fire He was
charged and convicted of arson. The Court reasoned that he was under a duty to take some
action to put out the fire.
-by continuing act. See Fagan v Metropolitan Police Commissioner (1969) 1 Q.B 439. In R v
Miller, In Faghan’s case, the defendant was stopped by a police constable but he drove and
stopped on the constable’s feet and refuse to move away. He was convicted of criminal
LPU 301
Faculty of Law, University of Ibadan
10
Introduction to Criminal Law
2022
assault. In Jones v State, ‘D’ raped a girl causing her so much distress and pain that she fell
into a creek and he intentionally failed to rescue her. He was convicted of murder.
The Principle of Causation
Where crimes are defined to include not only conduct but the result of such conduct, it must
be established that the accused conduct caused the proscribed result. It is not sufficient that
the Defendant committed some acts or conducted himself in certain suspicious manner alone.
This is regarded as the principle of causation. This principle is specifically required in
culpable homicide cases. In a murder case for instance, the prosecution must not only
establish the commission of assault on the person of the victim by the accused but also that
the act of the accused caused the death of the victim in fact and in law. See the case of R v
White in respect of factual causation where White admitted poison to his mother who
subsequently died of heart attack and not of food poisoning. White was acquitted of murder
because his act in fact did not cause the death of his mother. He was however guilty of
attempted murder. See the provision of s.314 of CC in respect of legal causation (a year and a
day rule).
The Concept of Mens Rea - Section 24 of the Criminal Code
Until the 12th century, a man might be held liable for any harm simply because his conduct
caused that harm without any proof of blameworthy state of mind whatsoever on his part.
However, following the Latin maxim; ‘actus non facit reum nisi mens sit rea’, in any given
criminal case the prosecution must establish that the accused possessed the requisite guilty
state of mind. Except for strict liability offences, mens rea which depicts the guilty or
culpable state of mind of the accused must be proved in every criminal trial. While there is
not statutory definition of ‘mens rea’ Lord Diplock in R v Caldwell 1982 AC 341 states that
‘mens rea is by definition a state of mind of the accused himself at the time he did the
physical act that constitute the actus reus of the offence. It cannot be the mental state of some
non-existent hypothetical person.’ Several words are typically used to depict the mens rea of
an offence and these words vary from crime to crime. Such words include nut are not limited
to: ‘knowingly’; ‘falsely’; ‘fraudulently’; ‘wilfully’; ‘unlawfully’; ‘maliciously’;
‘negligently’ etc. Essentially, the concept of Mens rea would be examined in four basic
forms: intention; recklessness; negligence and knowledge.
i. Intention – s.24
There is no statutory definition of word ‘intention’. Following judicial decisions however,
intention describes the decision to bring about, in so far as it lies within the power of the
accused, a particular consequence whether the accused desired the resultant consequence or
not. See the case of Bakare v State (1987) 1 NWLR 579. Intention depicts the aim or purpose
of the accused person to bring about the elements which make up the crime. Intention need
not be directed at a particular aim or purpose except where specific intent to cause a
particular act/result is required as one of the elements of the offence. Transferred malice is
however unknown to Nigerian criminal law. See Hyam v DPP (1975) AC 55 where the house
of Lord held that the foresight of a consequence is not the same as intention but it may be
evidence from which intention may be inferred or found. Intention is essentially different
LPU 301
Faculty of Law, University of Ibadan
11
Introduction to Criminal Law
2022
from motive neither does premeditation equate intention although, these may be an evidence
of intention. S. 24 expressly provides that motive is generally irrelevant in determining
criminal responsibility except where expressly stated.‡ However, the motive of a defendant
could assist the court in deducing his intention. In R v Steane [1947] KB 997 (CA), a
defendant who assisted the enemy during war because he feared that his family would be sent
to concentration camp was held not to have intended to assist the enemy. See the case of R v
Bodkin Adams [1957] Crim LR 365.
Proof of Intention
In reality it is often difficult to establish intention as it is not capable of positive proof as in
the case of ‘actus reus’ and this was acknowledged by Bryan C.J in his statement in an old
English case where he was reported to have said that ‘the thoughts of man in not triable for
the devil himself knoweth not the thoughts of man.’ However, Bowen LJ in Edgington v
Fitzmaurice (1885) 29 Ch. D. 459 @ 483 is reported to have stated that ‘the state of a man’s
mind is as much fact as the state of his digestion.’ Thus, proof of intention is a matter of
evidence which may be established from overt acts. In other words, intention may be inferred
with some degree of certainty from physical, overt/manifest act. For instance, the intention to
kill a person may be inferred from the severity and frequency with which an assault is
inflicted on the victim by the assailant. See R v Onoro [1961] 1 All NLR 33 In proving
intention, the court generally, measures the mind of the accused person against that of a
hypothetical reasonable man in the accused shoes i.e. the court relies on the presumption that
a man intends the natural and probable consequences of his actions. It should however be
noted that this presumption is rebuttable and it is not foolproof of the accused’s intention. The
use of a reasonable man’s test is however to aid the court in arriving at the subjective
intention of the accused therefore if evidence exist which shows what the accused actually
intended, this should be followed without reverting to any presumption. See Nungu v R
(1953) 14 WACA 379. See Also R v Ntah [1961] 1 All NLR 590
Voluntariness of Conduct
Voluntariness of conduct also underlines the presence of intention on the part of the accused
in respect of the commission of a crime. s.24 excludes criminal liability for conducts which
‘occurs independently of the exercise of the will of the accused person’. Thus, an individual
will not be said to be acting unless there a willed muscular movement. In this context, an
action is willed if it is in response to instruction or direction from the mind. Hence, for a
person to be acting, the movement or action must be voluntary. Consequently, an act would
be involuntary if it is a consequence of a reflex action or a convulsion or it occurs during
sleepwalking, an epilepsy episode or as a result of hypnotism. In the case of Bratty v AG
Northern Island, Lord Denning reiterated that:
[n]o act is punishable if it is done involuntary and an involuntary act in this context
means an act which is done by the muscles without any control by the mind such as
‡
Motive is usually seen as the driving force behind intention. Some offences may require specific proof of
motive.
LPU 301
Faculty of Law, University of Ibadan
12
Introduction to Criminal Law
2022
spasm, a reflex action or a convulsion or an act done by a person who is not conscious
of what he is doing
See the case of Martin v State where the conviction of a drunken man who had been carried
from the privacy of his home to the highway by a police officer, was quashed because he did
not make voluntary appeared on the highway in his drunken state. Note that in situations
regarding involuntariness of conduct, even though the requite actus reus is present, no
criminal liability is incurred because the requisite mental state is not present.
ii. Recklessness
Recklessness on the other hand underscores a situation where although the accused did not
intend to bring about the proscribed act or result, but goes on to take unjustifiable risk.
Recklessness means taking an unjustifiable risk where the conduct/action has no social value
or utility. Recklessness means taking a risk without a thought that it might result in harm or
being indifferent to the consequence of the risk. For example, ‘B’ throws a baby from the
topmost floor of a building or a driver drives into a busy street on high speed. In the two
instances both persons are reckless and may be criminally liable. On the other hand, an
ambulance driver or firefighting truck driver may be justified in reckless driving because of
the social utility involved. Thus, where a person consciously takes an unjustified risk and
maintains indifference to the probability that the consequences might be risky. The test from
recklessness was laid down in R v Cunningham (1957) 41 CAR 155 where ‘D’, the accused
towed a gas meter from the wall of a seller of an unoccupied house, to steal the money in it.
‘D’ left the gas gushing out. The gas escaped to a neighbouring room and was inhaled by ‘B’
whose life became threatened. ‘D’ was convicted of maliciously administering a noxious
thing so as to endanger life. Two conditions were subsequently laid out:
i. the awareness or foresight of the existence of a risk resulting from the act of the
defendant
ii. the risk was unreasonable or unjustifiable.
The first condition relates to whether the accused foresaw the risk and not just that the risk
was obvious or would have been foreseen by a reasonable person. Thus, the first condition is
determined by a subjective test. See R v Stephenson (1979) Q.B 695 C.A where the accused
would have been convicted for arson but for the fact that he suffered from a mental condition
that affected his reasoning. His earlier conviction was quashed. See also R v Pigg (1982) 2
All E.R. 591. The second condition which relates to justifiability or reasonableness of the risk
is determined by an objective test and not subjected to the accused reasoning unlike the first
condition. The question is whether such a risk will be justifiable by a reasonable man in the
same circumstances as the accused. See R v Elliot (1983) All E.R. 1005.
iii. Negligence
The law will input intention where the accused may or may not intend, desire or foreseen the
proscribed act or result but does not live up to the standard of care reasonably placed on him
in such circumstance. This is because the law inputs the duty on him to have foreseen such
act or consequence. Except in relation to specific offences such a culpable homicide (s.343),
LPU 301
Faculty of Law, University of Ibadan
13
Introduction to Criminal Law
2022
negligence is rarely required to establish or prove mens rea. For instance, ‘A’, a domestic
staff who has been employed to care for and mind ‘B’, a toddler is expected to exhibit a
reasonable standard of care to ensure that the child is kept away from danger. Where ‘B’
under his watch, strays into the highway and he is crushed by a moving vehicle, ‘A’ may be
negligently liable for ‘B’ death. Thus, negligence underscores inadvertence to the probability
of the risk although the defendant may not have reasonably foreseen or even be aware of the
risk.
iv. Knowledge
This relates to a positive belief that a state of affairs exists or suspicion of the existence of a
particular state of affairs and deliberate decision not to make enquiries as to the veracity of
the suspicion. In other words, intention may be deduced where a defendant acted knowing or
believing that a particular state of affairs existed. For instance, the offence of receiving stolen
goods requires proof that the accused knew or believed that the goods were stolen (s. 427
CC). Mere suspicion may not be enough; this does not mean the accused must be absolutely
certain that the circumstances or state of affairs exists. In R v Reader (1977) 66 Cr App R 33,
the Court held that the belief that a property might have been stolen is not enough for a belief
that it is stolen. However, this does not mean that the defendant must be absolutely certain
that the circumstances exist. Where a person assumes a set of facts to be true and he has no
serious doubts about them, then the state of mind of the person amounts to knowledge. See R
v. Griffiths (1974) 60 Cr App R 14. Knowledge is also imputed where the accused was aware
that there was a risk that certain circumstances existed but maintained ‘wilful blindness’ or
decides not to make further enquires in respect of its veracity or otherwise.
Concurrence of Actus Reus and Mens Rea
It is a general principle of criminal law that the actus reus and the mens rea must coincide,
concur or intercept at the same point in time to establish the commission of a true crime. For
instance, ‘killandgo’ has been nursing the idea of killing ‘Diehard’. While on a hunting
expedition, ‘Killandgo’ shoots at an escaping prey in the bush at night which turns out to be
‘Diehard’ instead of the prey and ‘Diehard’ subsequently dies therefrom, it would be difficult
to establish the offence of murder against ‘Killandgo’. This is because while the actus reus is
present there is no mental element to establish any offence against ‘Killandgo’ at the time the
shooting occurred. It would make no difference where ‘Killandgo’ expressed joy over the
death of ‘Diehard’ after finding out his identity. In criminal law no amount of ex post facto
malice can turn what is originally a justified assault into a crime. However, the traditional
view that there must be a concurrence of the two elements that make up a crime at the same
point in time has been modified owing to certain situations.
The more refined and current view with respect to concurrence of actus reus and mens rea is
that the requirement will be met where the mens rea ignites or actuates the actus reus even
though they did not concur at the same point in time. See the case of R v Thabo Melli (1954)
1 All E.R. 373 where four men acting in concert agreed to kill the deceased and then make it
appear like an accident. Thabo Melli invited the victim to a hut, gave him beer and when he
was intoxicated, he clubbed him on the head. Believing him to be dead, he rolled the body
LPU 301
Faculty of Law, University of Ibadan
14
Introduction to Criminal Law
2022
over a cliff. Medical evidence in fact showed that it was the second act of the accused that
killed the deceased, Thabo Melli was convicted of murder. Ordinarily the strict principle of
concurrence of actus reus and mens rea would have led to an acquittal of the accused but the
court held that the appellant (Defendant) could not divide what was in reality, a series of
transaction into component parts but rather the transaction must be viewed as a whole. As
such, if part of the transaction was accompanied with mens rea, then this suffices to establish
criminal liability.
Thus, where the defendant had mens rea at one point in time and then later without mens rea
performs the actus reus, he may be criminally liable. As long as the act performed with mens
rea and the act which constituted the actus reus could be described as part of one transaction.
Also where the defendant commits the actus reus at one point in time without the requisite
mens rea but at a later point in time he has the mens rea, he may be criminally liable. For
instance, where the Defendant while asleep starts a fire and then afterwards realises what he
has done but runs off. See R v Miller (Supra).
The case of Thabo Melli’s case was distinguished from Chiswibo’s. In R v Chiswibo (1961) 2
S A 714, the court convicted the accused of attempted murder rather than murder based on
the notion that burying of the deceased’s body was not part of the same preconceived
transaction as there had been a wide time lag between the first and second acts. In R v Shorty
three accused persons were convicted criminal offences in varying degrees of liability. The
first accused had assaulted the deceased with the intent to kill him, he was assisted by the
second and third accused, all believing him to be dead disposed of his body by putting him
down a sewer where he subsequently died of drowning. While the first accused was held
guilty of attempted murder, the second and third accused were held guilty for being
accomplices, accessories after the fact. See also the cases of R v Church (1965) 2 All E.R 72,
R v Jakeman (1982) CAR 223 and R v Masilela (1968) 2 S.A 558.
For further readings, consult all recommended texts and applicable law reports including the
following;



Criminal Law in Nigeria by Okonkwo and Naish
Criminal Law by Smith and Hogan 14th ed.
Criminal law in Nigeria by Professor Oluyemisi Bamgbose and Hon. Justice Sonia
Akinbiyi

Criminal Law Text Cases and Materials by 3rd ed. Jonathan Herring

Card, Cross and Jones: Criminal Law 20th ed.

Criminal Code Cap C38 LFN 2004
LPU 301
Faculty of Law, University of Ibadan
15