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What Are the 7 Principles of Criminal Law?

Due to the severity of criminal charges and associated punishments, the criminal justice system has implemented different ways to ensure that innocent people are not wrongly convicted for crimes they did not commit. But unfortunately, a lot of innocent people still end up in jail. This is why the service of professional criminal lawyer Kaysi Fagan is needed. These professionals understand the principles of criminal law.

The principles of criminal law are the rules that control the conduct of a criminal trial. They determine whether a person is guilty of a crime and, if so, how much prison time they will receive for their crime. Read on to discover the seven principles of criminal law.

Definition of Criminal Law

This is a system of laws that the government uses to punish offenders. Like any other aspect of the law, it has its set of rules and standards for collecting evidence, investigating, arresting people, and convicting them in court.

Criminal law is the body of rules and regulations that are created and enforced to govern the behavior of people who commit crimes. Criminal law does not only cover how defense lawyers should plead their cases in court; it also explores the importance of punishing an offender.

The criminal law system is quite complex and comprises ordinances, procedures, and statutes which attorneys and juries must understand. The seven principles also guide them.

The Principles of Criminal Law


The principle of legality is one of the most important principles of criminal law. It states that people cannot be convicted of a crime if there is no law against such crime. If a person commits a crime, but no law says they can't do it, then they are not guilty of committing the crime.

For example, if someone kicks an animal and they are caught by people. Although the act may seem illegal, if there is no law against kicking animals in the state, such a person can't be convicted. Their conviction will be dismissed because they are not guilty according to the law.

Actus Reus

This principle states a person is found guilty of committing a crime only when they have actually committed such an act. The result of the action is what forms the basis of criminal liability.

For example, a robber can only be charged for committing the crime if they are caught in the act and not because they planned to do it.


The principle of criminal law, known as causation, is based on the idea that every crime must have a cause. Before you can be found guilty of a crime, the prosecuting attorney must be able to prove beyond doubt that your actions were the direct result of a particular circumstance or event.

For example, if you commit an intentional act that causes another person to die, then you would be guilty of murder because your act directly resulted in their death. However, if you sold an item to another person, and the item was used in creating a bomb, you may not be found guilty.

Harm Incurred

Harm Incurred is a principle of criminal law that states that if a person commits an act that causes harm to another, then they have committed a crime. However, if their actions haven't harmed anyone, then the case will be dismissed.

It's an important principle because it helps to prevent people who didn't cause any harm from getting jailed. It also helps to ensure that people who commit crimes are held accountable for their actions.

Mens Rea

Unlike actus reus, Mens Rea considers the mental state of a person at the time when they committed a crime. This principle of criminal law states that to be guilty of a crime, a defendant must have acted with the right state of mind. In other words, you need to know what you're doing to be charged with the crime.

For instance, someone who has a mental disorder can't be charged guilty of murder because they were not in their right senses at the time of the crime. A prosecuting attorney will have to provide evidence stating that the defendant is in the right frame of mind before they can be charged guilty.


The principle of concurrence is used to describe the combination of mens rea and actus reus and check if there is an alignment between the two. It clearly states that before a person can be found guilty of a crime, there must be a concurrence between both the mental intent of committing the crime and the physical act of carrying it out.

Therefore, even if a crime involves actus reus, but there is no proof that the crime was committed with a right mind, the criminal defense attorney only needs to provide evidence that the defendants were unaware of their actions at the time of the crime, and they may go unpunished for the crime.


The principle has to do with the way the authority punishes people who have broken the law. This can be done through imprisonment, fines, community service, or even death. The severity of the crime often determines the punishment. In other words, a thief will not get the same punishment as a murderer. Punishment is used for five different purposes, which are stated below:

  • Incapacitation: This removes the criminal from society, thus preventing the likelihood of future crimes.
  • Deterrence: To deter future offenders from committing a similar crime.
  • Retribution: This informs the victim that the criminal has been punished accordingly.
  • Restitution: It is used to punish a criminal by making them pay fines that cover the victim's costs.
  • Rehabilitation: This is used to make the defendant a better person.

In conclusion, these seven principles of criminal law outline the whole process involved in arresting a person for committing a crime, from the point of arrest to finding them guilty of the crime. They are crucial to the justice system, as they help the judge and the jury makes the right decisions regarding guilt.