Accessory After the Fact / 18 U.S.C. Sec. 3 is a federal criminal statute that prohibits one from assisting, harboring, or concealing someone who has already committed a felony. It is also known as aiding and abetting. There are two types of Accessory After the Fact / 18 U.S.C. Sec. 3: 1. Aiding and Abetting: This is when someone helps or encourages another person to commit a crime. This can include providing advice, assistance, or providing a safe place for a criminal to hide. 2. Harboring and Concealing: This is when someone hides or protects a criminal from detection or apprehension. This can include providing a place for the criminal to stay, or hiding or destroying evidence. The penalty for Accessory After the Fact / 18 U.S.C. Sec. 3 is up to one year in prison, a fine, or both.