Would be taking a supporting role. ‘Looper’ and ‘Expendables 2’ star Bruce Willis is in negotiations to take a role in ‘Traitor’ helmer Jeffrey Nachmanoff’s spy thriller ‘American Assassin.’ The 11th book in a series centring on CIA Agent Mitch Rapp, ‘American Assassin’ is prequel telling the story of how, as a college scholar and athlete, tragedy forged Rapp’s path to become a ruthless hunter of terrorists for the CIA. Variety reports that Willis is circling the role of a CIA operative who serves as Rapp’s mentor. The role of Rapp has yet to be cast. Lorenzo di Bonaventura is on board as producer with the project expected to kick off principal photography in autumn 2013.