Accessory. Anything which is joined to another thing as an ornament, or to render it more perfect, or which accompanies it, or is connected with it as an incident, or as subordinate to it, or which belongs to or with it. Adjunct or accompaniment. Louis Werner Saw Mill Co. v. White, 205 La. 242, 17 So.2d 264, 270. A thing of subordinate importance. Aiding or contributing in secondary way or assisting in or contributing to as a subordinate. Gilfoil v. Greenspon, La.App., 216 So.2d 829, 831.

Criminal law. Contributing to or aiding in the commission of a crime. One who, without being present at the commission of a felonious offense, becomes guilty of such offense, not as a chief actor, but as a participator, as by command, advice, instigation, or concealment; either before or after the fact, or commission; a particeps criminis. Model Penal Code, § 2.06.

One who is not the chief actor in the offense, nor present at its performance, but in some way concerned therein, either before or after the act committed. One who aids, abets, commands, or counsels another in the commission of a crime. See also Abettor; Aid and abet; Accomplice.

Accessory after the fact. A person who, knowing a felony to have been committed by another, receives, relieves, comforts or assists the felon, in order to enable him to escape from punishment, or the like. Robinson v. State, 5 Md.App. 723, 249 A.2d 504, 507; 18 U.S.C.A. § 3. See also Harbor; Obstructing justice.

Accessory before the fact. One who orders, counsels, encourages, or otherwise aids and abets another to commit a felony and who is not present at the commission of the offense. Com. v. Leach, 455 Pa. 448, 317 A.2d 293, 294. The primary distinction between the accessory before the fact and the principal in the second degree is presence. Virtually all states have now expressly abrogated the distinction between principals and accessories before the fact; the latter now being classified as principals.

Accessory during the fact. One who stands by without interfering or giving such help as may be in his power to prevent the commission of a criminal offense.

SOURCE: Black's Law Dictionary, Sixth Edition