ah right, i misread what ya said. Still who would even have a role like that? also to explain Shelly De Killer is an assassin who leaves a card behind, his signature, a shell card which basically is to claim credit for his kills to protect his client from being accused but he also has some honor and certain rules that must be obeyed and will do anything to protect his client if anything goes wrong.
Bobby Fulbright is a spy who killed, who knows how many people, but his name The Phantom pops up through the game Ace Attorney Dual Destinies and near the end when he is exposed he is trying to find his original real face and has forgotten it because how many faces he has.
If Von Karma is in the game i expect he is a mafia because the dude will do ANYTHING for his perfect record and has such a commanding authority he can intimidate the judge into submission.