Marvin de Luca is the head of the American mafia and is one of the first crime bosses you need in Objective 2- Head of The Underworld. To discover the mission send 10 worker to the westcoast plotting. I discoverd him in another session by plotting somewhere else too but it takes longer and you might wanna use technicians. You need 5 technicians to capture him on the "West Coast" better use 10 as your minions are complete failures.