Actus reus is the act—or the omission or failure to act when there is a duty to act—that comprises the physical elements of the commission of a crime. The actus reus generally must be voluntary bodily movements that constitute a crime.
In contrast, mens rea (meaning “guilty mind”) is the criminal intent element of a crime. It is the intent to commit a crime, or the knowledge that the action, or failure to act when there is a duty to act, will result in the commission of a crime.

In Alabama, as in other jurisdictions, the concept of actus reus requires that a defendant must have engaged in a voluntary act, or an omission when there is a legal duty to act, that constitutes the physical elements of a crime. This means that for a person to be found guilty of a crime, it must be shown that they actually performed the actions that are considered criminal, or failed to act when they were legally required to do so. For instance, if a person has a legal obligation to provide food to a dependent and fails to do so, resulting in harm, that omission could be considered actus reus. On the other hand, mens rea refers to the mental state of the defendant at the time of the crime. Alabama law recognizes various levels of mens rea, from intentional to reckless or negligent conduct, depending on the crime. To secure a conviction, the prosecution typically must prove that the defendant had the requisite mens rea to commit the crime in question. This means showing that the defendant had the intent to commit the crime or was aware that their actions would likely result in a criminal outcome.