Latin for “guilty act,” actus reus is the act or omission forming the physical element of a crime. These acts or omissions are usually listed in the governing jurisdiction’s statutes.
Before a defendant can be proven guilty of a crime, actus reus and mens rea must be proved beyond a reasonable doubt.
Actus reus is one of two broad elements that the prosecution must prove beyond a reasonable doubt. The other element is mens rea, or criminal intent.
Using a murder case as an example: A physical act producing the victim’s death – shooting, stabbing, poisoning – is the actus reus. After proving actus reus, the prosecution must prove that the defendant’s physical action was intended to cause the death of the victim. This two-step process protects defendants from prosecution for accidents or other scenarios in which the defendant did not intend to commit a crime.