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 Rhode Island, 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 the individual's actions or inactions must be deliberate and lead to the fulfillment of the crime's statutory elements. For instance, if a statute defines burglary as 'entering a dwelling with the intent to commit a felony therein,' the act of entering the dwelling would be the actus reus. On the other hand, mens rea refers to the mental state of the defendant at the time of the crime. Rhode Island law recognizes various levels of mens rea, such as intent, knowledge, recklessness, and negligence, depending on the crime. The prosecution typically must prove that the defendant had the requisite mens rea to be found guilty of the offense. For example, if the crime requires 'intent,' the state must show that the defendant purposefully engaged in conduct that constitutes the offense. Both actus reus and mens rea are fundamental components that must be established for a conviction in criminal cases in Rhode Island.