Different Types of Defences in Criminal Law

When someone is accused of a crime, it does not automatically mean they are guilty. Criminal law provides a variety of defences that can be used by the defendant to either justify their actions or explain their innocence. Understanding these defences can be crucial for anyone involved in a legal situation because the right defence can lead to a significant reduction in penalties or even a full acquittal. In this article, we explore the different types of criminal defences, how they work, and the strategies that lawyers often use in court to defend their clients.

Self-Defence: Protecting Oneself from Harm

One of the most commonly known defences in criminal law is self-defence. When a person feels that their life or safety is in immediate danger, they have the right to defend themselves, even if that results in harm to another person. This is typically applied in cases involving physical assault, robbery, or even murder.

For example, imagine being attacked in a dark alley. You’re scared for your life and, in a desperate attempt to protect yourself, you fight back and seriously injure the attacker. In such cases, the legal system often allows the defendant to argue that their actions were necessary to prevent greater harm from happening to themselves.

However, the principle of proportionality plays a key role here. The level of force used in self-defence must be reasonable in comparison to the threat. If a person uses excessive force that goes beyond what was necessary to stop the attack, their claim of self-defence may be weakened. For example, if someone attacks you with a fist, responding by pulling out a firearm may be seen as an excessive reaction, depending on the specific circumstances.

Duress: Acting Under Threat

Another important defence is duress, where the defendant claims they were forced to commit a crime because they were threatened with immediate harm or death. This is a powerful defence when properly used, as it highlights the human instinct for survival. For instance, if someone is held at gunpoint and forced to rob a bank, they could argue that they only committed the crime because their life was at risk.

However, for duress to apply, certain conditions must be met:

1. Immediacy of the Threat: The harm being threatened must be immediate and unavoidable. There can’t be a delay or opportunity to escape the threat.
2. Proportionality: The crime committed under duress must be proportionate to the threat received.
3. No Reasonable Alternative: The defendant must show that there was no other reasonable course of action available to them at the time.

Insanity Defence: Lack of Mental Capacity

The insanity defence is one of the most well-known but often misunderstood defences in criminal law. When a person commits a crime but is found to be suffering from a severe mental illness at the time, they may not be held fully responsible for their actions. The legal system recognizes that mental illness can impair a person’s ability to distinguish right from wrong or control their behavior in certain situations.

A famous example of this defence is the case of John Hinckley Jr., who attempted to assassinate U.S. President Ronald Reagan in 1981. Hinckley was found not guilty by reason of insanity, as it was shown that he was suffering from psychosis and was not in control of his actions at the time of the crime.

However, the insanity defence is rarely successful and often requires a thorough psychiatric evaluation. Additionally, even if a defendant is found not guilty by reason of insanity, they may still be committed to a mental health institution for a lengthy period.

Mistake of Fact: Honest Error

In some cases, a person may commit a crime due to an honest mistake of fact. This defence applies when the defendant had a genuine belief that they were not committing a crime because they misunderstood or were unaware of certain facts. For example, if a person takes someone else’s bicycle from a park, believing it to be their own, they could argue that they made a mistake of fact and had no intention to steal.

It is important to note that this defence does not apply to ignorance of the law—only to errors regarding factual circumstances. If a person is unaware that their actions are illegal, they cannot use the mistake of fact defence.

Necessity: Choosing the Lesser Evil

The defence of necessity arises when a person commits a crime to prevent a greater harm from occurring. This defence is often described as "choosing the lesser of two evils." A classic example is breaking into a building to escape a natural disaster, such as a fire or flood. In such cases, the person is arguing that their illegal action (breaking and entering) was justified because it was necessary to avoid imminent danger.

For necessity to apply, the following elements are typically required:

1. Imminent Danger: The harm being avoided must be immediate and serious.
2. No Lawful Alternative: There must be no other legal way to avoid the harm.
3. Proportionality: The harm caused by the illegal act must be less than the harm being avoided.

Necessity can be a compelling defence in cases involving environmental activism, emergency situations, or survival scenarios.

Alibi: Proving Innocence through Absence

An alibi defence is one of the most straightforward and effective strategies in criminal law. If the defendant can prove that they were somewhere else at the time the crime was committed, they cannot be guilty. An alibi typically involves evidence such as witnesses, surveillance footage, or electronic records (e.g., phone or GPS data) that can confirm the defendant’s whereabouts.

For example, if a person is accused of a crime that occurred at 8:00 p.m. on a certain date, but they were dining at a restaurant across town with several friends at that exact time, they could present those friends as witnesses to establish their alibi.

Consent: Agreeing to the Act

In certain criminal cases, particularly those involving assault or sexual activity, the defendant may argue that the victim consented to the act, and therefore no crime was committed. Consent is a valid defence when both parties agree to the conduct and it is not illegal under the circumstances.

However, the issue of consent can be complicated and often comes down to interpretation. For example, in cases of sexual assault, the question of whether consent was freely given or coerced can be a central point of contention. Additionally, consent is not a valid defence in all cases—such as in statutory rape, where the law assumes that a minor cannot legally consent to sexual activity.

Entrapment: Induced by Law Enforcement

Entrapment occurs when law enforcement officers or government agents induce a person to commit a crime that they would not have otherwise committed. This defence is often used in cases involving undercover operations, particularly in drug or prostitution stings. For entrapment to be successful, the defendant must show that they were not predisposed to commit the crime and that the government agents’ actions led them to break the law.

It is important to note that entrapment does not apply if the defendant was already inclined to commit the crime and the law enforcement officers merely provided an opportunity. The key question is whether the criminal intent originated with the defendant or was instigated by the authorities.

Intoxication: Involuntary vs. Voluntary

Intoxication, whether from alcohol or drugs, can sometimes be used as a defence in criminal cases. The success of this defence largely depends on whether the intoxication was voluntary or involuntary.

1. Voluntary Intoxication: In most cases, voluntarily becoming intoxicated is not a valid defence. However, in some jurisdictions, it may be used to reduce the severity of charges if the defendant can prove that they were too intoxicated to form the intent to commit the crime.

2. Involuntary Intoxication: If the defendant was unknowingly intoxicated, such as being drugged without their consent, they may be able to use this as a defence. Involuntary intoxication can be a strong defence if it can be shown that the defendant had no control over their actions due to the effects of the drugs or alcohol.

Conclusion

The criminal justice system recognizes that there are many different circumstances under which a person might commit an illegal act. The variety of defences available allows for a nuanced approach to justice, where the unique factors of each case can be considered. Whether it's self-defence, duress, or an alibi, these defences play a critical role in ensuring that individuals are not wrongfully convicted for actions they were justified in taking or for crimes they did not commit.