A criminal charge of aiding and abetting is known as an accomplice crime, and may be brought against anyone who helps with the commission of a crime. Aiding and abetting charges vary from state to state (and under federal law), but generally require that the defendant knowingly and intentionally aided and abetted the principal(s) in each essential element of the underlying crime. A person charged with aiding and abetting is often not present when the underlying crime is committed, but has knowledge of the crime before the crime is committed, and assists with the commission of the crime by providing information, action, or financial support. If the person aiding and abetting has a sufficient degree of involvement in the crime, the participation may rise to the level of being a conspiracy to commit the underlying crime.

In Washington State, aiding and abetting is addressed under the accomplice liability statutes. According to RCW 9A.08.020, a person is considered an accomplice to a crime if they, with knowledge that it will promote or facilitate the commission of the crime, (1) solicit, command, encourage, or request another person to commit the crime; or (2) aid or agree to aid another person in planning or committing the crime. The law does not require the accomplice to be physically present at the scene of the crime to be charged. An individual charged with aiding and abetting is subject to the same degree of punishment as the principal offender. This means that if the underlying crime is committed, the accomplice can face the same penalties as the person who directly engaged in the criminal act. The concept of conspiracy, which involves an agreement to commit a crime and an overt act in furtherance of the crime, is also recognized in Washington State under RCW 9A.28.040. Both aiding and abetting and conspiracy require intentional participation and a level of knowledge about the criminal activity.