Common Criminal Defenses: Insanity, Self-defense, Duress, etc.
When a person commits a crime and is charged to court for his wrongdoing there are certain defences he can raise. When a person raises a defence, he is not denying the fact that he might have done something wrong or unlawful but that he should not be punished as a result of his state of mind at the time the commission of the offence. He is in essence saying that his mind is not guilty, though his conduct may have brought about a particular prohibited result.
Some defences are factual, e.g. an accused person may raise a defence of alibi that demonstrates he was not present at the crime scene at the time the crime was committed. Defence of insanity acknowledges that the accused committed the offence but that he should not be punished because of the state of his mind as a result of which he was in such a state of mental disease or natural mental infirmity as to deprive him of capacity to understand what he was doing, or of capacity to control his actions, or of capacity to know that he ought not to act or make the omission.
Intoxication under the Criminal Code does not offer any defence as a general rule. There are however exceptions to this general rule. One exception is that where intoxication is involuntary and is due to the malicious or negligent act of another person and the person raising the defence must not have known that such act or omission was wrong and also that he did not know what he was doing at the time of the act or omission.
The second exception in relation to the defence of intoxication is that the person charged was by reason of intoxication insane, temporarily or otherwise at the time of such act or omission. Intoxication under the Penal Code offers a defence provided the intoxication is involuntary. If the intoxication is voluntary there is no defence for such a person.
Types of Defence in Criminal Law
In criminal law, there are several types of defenses that can be used to challenge or mitigate criminal charges. Some common types of defenses include:
1. Self-defense
This defense is used when an individual claims that they acted in self-defense to protect themselves or others from harm. It typically requires showing that the use of force was necessary and proportionate to the threat faced.
2. Insanity defense
This defense is used when an individual claims that they were not mentally capable of understanding the nature and consequences of their actions at the time of the offense. It typically requires a showing of a severe mental illness or defect.
3. Alibi defense
This defense is used when an individual claims that they were not present at the scene of the crime when it occurred. It typically requires providing evidence or witnesses to support the claim.
4. Consent defense
This defense is used when an individual claims that the alleged victim consented to the actions that are being charged as a crime. It typically requires showing that the consent was freely given and informed.
5. Duress defense
This defense is used when an individual claims that they were forced or coerced into committing a crime under the threat of imminent harm. It typically requires showing that there was a reasonable fear of harm and no reasonable alternative to committing the crime.
A person who commits a crime because another person exerts extreme influence or compels him to do a wrongful act may raise the defence of duress.
6. Immature Age
A person under the age of seven years is not criminally responsible for any act or omission. Also, a person under the age of twelve 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 capacity to know that he ought not to do the act or make the omission. A male person under the age of twelve years is presumed to be incapable of having carnal knowledge.
7. Defence of Mistake
Mistake of fact constitutes a defence to criminal liability if it can be proved that due to the mistake, the accused person lacked the mental fault required to commit the crime in question. If a person takes another person' coat mistakenly believing that it is own coat, this mistake negates the intent to permanently deprive the owner of the thing required to commit the offence of stealing.
Note that mistake of law does not offer a defence in criminal law because of the general rule which says that ignorance or mistake of law is not a defence to criminal liability.
8. Self Defence
As a general rule, the law allows for a defence for action that reasonably appear necessary to protect oneself from the imminent or (immediate) use of unlawful force. For example, a person is justified in the use of deadly force in self-defence if he reasonably believes that deadly force is necessary to prevent an act that would cause immediate death or serious bodily harm to himself, his spouse, child or wards, servants or even his property.
When a person commits an offence and is arrested the first agency of criminal justice system he comes in contact with is the police. Section 214 (1) of the 1999 Constitution of the Federal Republic of Nigeria (as amended) establishes one Police Force for Nigeria. Section 4 of the Police Act, CAP 359, Laws of the Federation of Nigeria, 1990 provides the following as the general duties of the police.
- Prevention of crime;
- Detection of crime;
- Apprehension of offenders;
- Preservation of law and order;
- Protection of life and property;
- Enforcement of all laws and regulations with which they are directly charged; and such other military duties within or
- The performance of outside Nigeria as may be required of them by or under the authority of the Act or any other Act.
It would be of great importance to consider some of these powers exercisable by the police.