Criminal Law: Sources, Elements, Defences and Proof
Criminal Law in the Nigerian Bar examination tests your command of the general part of Nigerian criminal law: the sources that apply, the elements of liability, the recognised defences, and the rules on burden of proof. The examiner expects you to move between the Criminal Code, the Penal Code and the Administration of Criminal Justice Act 2015 (ACJA) without mixing them.
Sources and elements
The Criminal Code applies in the southern states and in federal prosecutions; the Penal Code applies in the northern states. The ACJA governs procedure in federal courts and the FCT, while state ACJLs govern state courts. Liability normally requires actus reus and mens rea, and the prosecution must prove both beyond reasonable doubt (Constitution s. 36(5)). Strict liability offences dispense with mens rea but are exceptional.
Defences that change the charge
Insanity follows the M'Naghten test: a defect of reason from disease of the mind such that the accused did not know the nature and quality of the act or did not know it was wrong. Intoxication is a defence only where it negatives the specific intent required for the offence. Provocation reduces murder to manslaughter where it would cause a reasonable person to lose self-control and the accused did not act in revenge. Self-defence requires a reasonable belief in imminent unlawful force and a proportionate response. Alibi is not a defence in law; it is evidence that undermines identification.
Worked example
A is charged with murder after stabbing B in a fight. A says B taunted him about his family and that he lost control. The prosecution proves the stabbing but not premeditation. The issue is not whether A was angry but whether the provocation was sufficient to deprive a reasonable person of self-control and whether A acted in revenge. If both are answered in A's favour, the conviction is for manslaughter, not murder. If A used a weapon after B had been restrained, the revenge element defeats the defence.
Traps
Do not cite Penal Code provisions in a Criminal Code state; do not treat alibi as a burden on the accused; do not confuse insanity with automatism; and remember that a no-case submission is not evidence.