Jericho (Fallout 3)

Jericho is a join-able NPC in Fallout 3, and is found in the town of Megaton. He wields a Chinese Assault Rifle. He also states that he has left the life of a raider in the Wasteland behind him, tired of the killing and violence. Jericho can become a companion with the Vault 101 Dweller, although the player must retain copious negative karma to do so. Jericho also requires that the Vault 101 Dweller pay him 1000 caps for supplies. If you talk to him some more he reveals that Moriarty hides his daily profits from his saloon in a footlocker at his bed, and that he wears the key around his neck.

Note: I lost Jericho after i was captured by the Enclave - after the videoscene Jericho was lost and nowhere to be found (others have experienced this after the virtual reality part of the main quest) - he will return to megaton after some time so don't worry too much