West's Encyclopedia of American Law | Abettor

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.