ABETTOR, a law term implying one who is present, actually or constructively, and aids and abets another to commit an offence. An abettor differs from an accessory (q.v.) in that he must be present at the commission of the crime ; all abettors (with certain exceptions) are principals in the second degree, and, in the absence of specific statutory provision to the contrary, are punishable to the same extent as the actual perpetrator of the offence.