Criminal law is a complex field where individuals accused of committing crimes have the right to defend themselves against charges. To do so, they often employ various legal defences aimed at establishing their lack of criminal responsibility or guilt. For international and local laws, I will be explaining the 8 major defenses that can exonerate an accused from criminal liability.
Defences in Criminal Law
In the course of criminal trial the accused may claim that certain fact or set facts in the case serve to exonerate him from liability. Below are the facts or defences that can exonerate an accuse from criminal liability:
An accident is any event which a reasonable man in the shoes of the accused would not have foreseen as likely or probable.
Section 24 of the Criminal Code of Nigeria has explained that a person is not criminally responsible for an event which occurs by accident, and that under the code it is probable that an accused is not held liable for any accidental event simply because it results from an unlawful act committed by him.
The exact meaning of an event occurring by accident may give rise to difficulty. In explaining this, Mansfield C.J quoted without comment, the following passage from Stephen’s Digest of the Criminal Law;
“An effect is said to be accidental when the act by which it is caused is not done with the intention of causing it, and when it’s occurrence as a consequence of such act is not so probable that a person of ordinary prudence ought, under the circumstances in which it is done, to take reasonable precautions against it.”
In the Australian case of Vallance v R (1961) 35 A.L.J.R 182, the accused fired an airgun at a group of children and hit one, but claimed that he intended only the frighten them and was not aiming to hit. The High court considered section 13 (1) of the Tasmanian Criminal Code which is in similar terms to the first paragraph of section 24 of the Criminal Code of Nigeria:
“No person shall be criminally responsible for an act unless it is voluntary an intentional; nor, except as hereinafter expressly provided, for an event which occurs by chance.”
He was acquitted. But on appeal, the Attorney-General of the High Court defined an event occurring by chance in terms of foresight. Dixon C.J said:
“I think this somewhat difficult phrase covers events which the person who might otherwise be criminally responsible neither intended nor for saw as possible result of his conduct: they must, too, be fortuitous in the sence that no one would resonably expect them to occur as a consequence if that conduct.”
Mistake is also one of the general defences in criminal law. In this case, it must be a mistaken belief in the existence of any state of thing. Mistakes of law are irrelevant because ignorance of the law does not afford any excuse for any act or omission which would other wise constitute an offence, unless knowledge of the law by the offender is expressly declared to be an element of the offence.
An instance where this defence has worked is in the case of Ogbu v R. One of the accused said at his trial that he did not know that it was contrary to law to pay bribe in order to induce the other accused to appoint him as village headman and therefore tax collector.
The trial Judge accepted the story and acquitted him. On appeal by the other accused, although the Federal Supreme Court had no power to convict the first accuse, they remarked that;
“We are not at present satisfied that the learned Judge was right in acquitting Utachia Okobi on those findings, and that if the matter ever fell to be decided by this court we should require cogent arguments to convince us that on a charge involving doing some act corruptly, ignorance of the law is a defence to a person who had an intent of a kind which the law regard as corrupt.”
For this defence to work properly, the mistake must be honest and reasonable. This double requirement is not merely reportitious. A mistake may be honest and yet not be reasonable. Conversely, a mistake may appear to be reasonable and yet not be a genuine mistake. In neither case the defence of mistake will not work.
3. Defence of Bona-fide claim of right:
The defence of Bona-fide claim of right is another general defence in criminal law. It is closely related to the defence of mistake. This defence will exonerate an accused if, in a charge relating to property, he shows that he was acting with respect to any property in the exercise of an honest claim of right and without intention to defraud.
Take for instance, if he takes some old corrugated sheets which have been lying around for a long time, and which he believes to have been abandoned; or if he seizes the complainants property in order to enforce payment of a debt, or become the complainant had withdrawn his services from a commercial project and by local custom his property was liable to seizure.
In the Nigerian case of IGP v Emeozo  WRNLR 213, the accused had demanded money from another man, alleging that he had committed adultery with the accused’s wife, and that if he did not pay, he would sue for compensation under the native law and custom (as he would be entitled to do against an adulterer). The magistrate not believing that adultery had in fact been committed, convicted under section 406 of the Criminal Code of Nigeria.
On appeal, Thomas J. allowed cited the case of R v Bernhard where it was stated that: “a person has a claims of right if he is honestly asserting what he believes to be a lawful claim, even though it may be unfounded in law or fact.”
It is important to note that this defence only works in respect offences relating to property. Accordingly, the claim of right is required to be honest.
4. Extraordinary emergency:
Another general defence in criminal law is the defence known as extraordinary emergency. A person is not criminally responsible if his act or omission was done under circumstances of “sudden or extraordinary emergency”.
The defence is closely related to cases of self-defence, compulsion or provocation and is made expressly subject to the law on those topics; a man who, for instance, kills in circumstances which are held to amount in law to circumstances of self defence, compulsion or provocation, would be prevented from falling back to the defence of emergency.
The emergency must be such that an ordinary person possesing ordinary power of self control could not reasonably be expected to act otherwise.
5. The execution of law and superior orders:
Apart from cases of emergency there are a number of other situations where a man may be forced by circumstances or in consequence of a lagel duty, take action which would be unlawful if the law did not make special provision for the case.
It is important to note in this respect that members of the military and police force are not immune from the ordinary rules of responsibility. Take instance, section 15 of the Criminal Code of Nigeria expressly provides that they are subject not only to the special law relating to them (eg the Police Act) but also to the Code provisions.
However, as a result of the special duties which have to be carried out by the police and armed forces, they are given certain powers to arrest and to use force which are not available to the private citizen.
No problem better illustrates the necessary arbitrariness of the legal concept of criminal responsibility that the problem of when to hold a child liable for an offence, because the solution is simply in the arithmetical terms. Generally, a child under the age of seven is not criminally responsible for any act or omission.
A child who is seven or over, but is under 12, is not criminally responsible for an act or omission, unless it is proved that at the time of doing the act or making the omission, he had the capability to know that he ought not to do the act or make the omission.
At the age of 12 a child becomes fully responsible according to the criminal law of Nigeria (this is different in some jurisdiction). However, under the Children and Young Peoples Act (CYPA), a child is described in section 2 as a person under 14, and a young person as anyone above 14 years of age but under 17.
As far as the question of age is connected, if it appears to a court that an offender was a child or young person at the time of committing an offence, he shall be presumed so, unless the contrary is proved.
7. Husbands and wives:
Cases that involves husbands and wives are also among the general defences in criminal law. The rule is that, neither of them can incur criminal responsibility for doing any act in respect of each other’s property. Thus, a husband could not be charged with wilfully setting fire to his wife’s house.
Exceptions to this rule
- It is to be noted that the rule applies only to offences against property. A husband can be guilty of assaulting his wife no matter how minor the assult is.
- The Rule applies only to the husband or wife of a Christian marriage. A Christian marriage according to section one of the Criminal Code of Nigeria is a marriage which is recognized by law of the place where it is contracted as the voluntary union for life of one man and one woman to the exclusion of all others.
- The husband and wife must be living together.
- It will not avail when the act is committed by a spouse who is “leaving or deserting” or “about to leave and desert” the others.
- Lastly, there will be no defence where the act is accompanied by an intention to injure or defraud some third party.
Apparently, insanity is also one of the general defences in criminal law. The line between the responsible and the not responsible has been exceedingly difficult to draw in this branch of law. This is partly because attitudes to the responsibility of the mentally disturbed are so comfused; and partly because the lawyer is not sure how to treat the evidence of the medical expert.
There have been many test propounded to determine the degree of mental disorder that will suffice for the defence of insanity. One of the foremost theories was by M’Naghten (1843). Accordingly, the Durham Rule was also propounded.
In general, intoxication is not a defence to a criminal charge. But there may be a defence where intoxication is involuntarily; and even voluntarily intoxication may have some mitigating effect on Criminal liability. In fact, although intoxication is no excuse and a drunken man is legally no better off than a sober man, he is also legally no worse off. The Rule guiding voluntary and involuntary intoxication is provided for in section 29 (2) (a & b) of the Criminal Code of Nigeria.
Section 29 (2) (a) of the Criminal Code provides a defence for any person who commits an unlawful act in a state of intoxication which was caused without his consent by the malicious or negligent act of another person, and by reason of which he did not know that such act or omission was wrong or did not know what he was doing.
The Rule as to consent presumably means that the defence is defeated only if the consent is given with full awareness of the true position.
Haven known the various defences that exonerate a person from criminal liability, it is important to also remember that the court works with facts which are proven before it. In light of that, none of the above general defences of criminal law will work where it is not proven, beyond reasonable doubt, that the defence actually exist.