Actus Reus Non Facit Reum

Actus Reus Non Facit Reum is a legal principle stating that the physical act (actus reus) alone does not constitute a crime unless it is accompanied by a guilty state of mind (mens rea). This principle highlights the necessity of both the wrongful act and the intention behind it for criminal liability.

The maxim originates from English common law principles, reflecting the necessity of both the act and intent in proving a crime. It underscores a fundamental aspect of criminal justice that dates back to the development of legal standards in medieval Europe.

In modern law, this maxim is often employed to analyze cases involving criminal liability, ensuring that individuals are not punished for unintentional acts without the requisite mental state. Courts frequently reference this principle when determining degrees of culpability and appropriate charges.

• A person causing an accident by accidentally dropping an object does not constitute a crime unless there was intent to cause harm.
• A person who accidentally enters someone's property but has no intention to trespass may not be held liable for trespassing.

• R v. Cunningham [1957] 2 QB 396