A criminal accomplice is a person who knowingly, voluntarily, or intentionally assists another person in the commission of a crime—or under some circumstances, a person who fails to prevent another person from committing a crime. Unlike a person who aids and abets a crime by helping with the planning of the crime but is often not present at the scene of the crime—and unlike an accessory after the fact, who is not present at the scene of the crime but assists after the commission of the crime to help the perpetrator avoid arrest or punishment—an accomplice actively participates in the commission of the crime. For example, a person who acts as a lookout or getaway driver for a bank robbery is an accomplice.

In many states the traditional distinctions between the culpability of accomplices and principals to a crime have been replaced by statute—including the felony murder rule that may make an accomplice guilty of first degree or capital murder if he was the lookout or getaway driver for a bank robbery that resulted in a death.

In Vermont, the concept of a criminal accomplice is addressed under the state's criminal laws. An accomplice is someone who assists in the commission of a crime, doing so knowingly and intentionally. Vermont law does not strictly differentiate between principals and accomplices; instead, anyone who aids in the commission of a felony or misdemeanor can be charged as if they had committed the crime themselves. This means that a lookout or getaway driver in a bank robbery can be charged with the same offenses as the person who actually carries out the robbery. Furthermore, under Vermont's felony murder rule, if a death occurs during the commission of a felony such as a bank robbery, an accomplice can be charged with murder, even if their role was limited to being a lookout or getaway driver. The severity of the charges can escalate to first degree or even capital murder, depending on the circumstances of the crime and the resulting harm.