An unlawful act is a violation of the legal laws, rules and duties of a society. In every civilized society, a code of behavior exists that governs how people must behave. If a person violates that code of behavior, the action in violation is considered an unlawful act.
Many different codes and systems exist for regulating behavior. Some countries, such as the United States and United Kingdom, operate on a common law system. Other countries, such as France, operate on a civil law system.
Under a common law system, there are several sources of law. The legislature or executive branch can pass formal statutory laws, which are written laws published in code books. Judges can also make law in the form of case law, which means that when a judge sets forth a rule, that rule applies in other cases as well.
In a civil law system, all law is written, codified law so common law or judge-made rules are not legally enforceable. France is a civil law system, and even Louisiana in the United States has incorporated many civil law principles into its state courts. In a civil law system, only this written formal law is enforced.
Regardless of where the law comes from, the law imposes legal duties on every person. Breach of these legal duties usually carries some form of penalty. The penalties may be either civil penalties or criminal penalties.
An unlawful act that is a violation of criminal law subjects a person to criminal sanctions. For example, in every country, criminal law stipulates that a person should not kill anyone else. A violation of this criminal law can subject the murderer to penalties including imprisonment or death.
When a person commits an unlawful criminal act, only a government official can bring charges relating to the criminal act. In most jurisdictions, criminal sanctions can only be imposed after a fair trial. In the United States, the Constitution’s due process clause guarantees a person a trial in which the prosecutor must prove the individual’s guilt beyond a reasonable doubt before criminal sanctions can be imposed for the unlawful act.
By definition, all unlawful acts require a physical action. A person cannot be punished for thinking about doing something illegal or wishing he did something illegal. As soon as a person takes steps toward carrying out an unlawful act, however, even if those steps are merely preliminary, the person may be subject to criminal sanctions. For example, attempted murder laws and conspiracy laws prohibit the planning or attempt of an unlawful act, making the planning itself an unlawful criminal action punishable by criminal sanctions.