One who commands, advises, instigates, or encourages another to commit a crime. A person who, being present, incites another to commit a crime, and thus becomes a principal. To be an abettor, the accused must have instigated or advised the commission of a crime or been present for the purpose of assisting in its commission; he or she must share criminal intent with which the crime was committed.
A person who lends a friend a car for use in a Robbery is an abettor even though he or she is not present when the robbery takes place. An abettor is not the chief actor, the principal, in the commission of a crime but must share the principal's criminal intent in order to be prosecuted for the same crime.
ABETTOR, crim. law. One who encourages or incites, persuades or sets another on to commit a crime. Such a person is either a principal or, an accessory to the crime. When present, aiding, where a felony is committed, he is guilty as principal in the second degree ; when absent, he is merely an accessory. 1. Russell, 21; 1 Leach 66; Foster 428.