You could be:

aiding a felon

accessory before the fact

accessory after the fact

Accessory before the fact implies that a defendant planned in or assisted with the gathering items necessary for an activity that lead up to the point that the planned crime was committed. After the fact implies the same but they assisted with or gathering items to hide the crime committed.

It means that you either knew about a crime before it was committed or you participated in the planning of a crime. This term is now either, conspiracy or accomplice. Both terms carry long prison sentences

Either an accessory before or after the fact.

There is no specific crime called "accessory after the fact," and in the US the notion of "accessory" in general is largely an obsolete concept. An "accessory before the fact" is now generally regarded as an accomplice, flat out, and charged with the same crime as the principal. The old concept of "accessory after the fact" is now largely subsumed in more specific charges (usually of lesser severity) like "obstruction of justice," "tampering with evidence," or "harboring a felon".