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In many states the traditional distinctions between the culpability of accomplices and principals to a crime have been replaced by statute—including the felony murder rule that may make an accomplice guilty of first degree or capital murder if he was the lookout or getaway driver for a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 Alaska, an individual who assists in the commission of a crime is considered an accomplice and is subject to criminal liability. Alaska law does not strictly differentiate between principals and accomplices; both can be charged with the same crime. This means that someone acting as a lookout or getaway driver during a crime, such as a bank robbery, can be charged with the same offense as the person who directly commits the criminal act. Furthermore, under Alaska's felony murder statute, if a death occurs during the commission of certain felonies, an accomplice can be charged with first-degree murder, even if they did not directly cause the death. This is because their participation in the felony contributed to the circumstances that led to the homicide. Therefore, being an accomplice in Alaska carries significant legal risks, and individuals in such roles can face severe penalties, including those associated with the most serious crimes.