'Magnum P.I.' Cast: Where Are They Now? Roger E. Mosley aka Theodore "T.C." Calvin T.C. was one of Magnum's closest pals, and one of Magnum's go-to guys when he needed to get somewhere that the Ferrari wouldn't take him. Mosley has remained active in TV land since 'Magnum,' with recurring roles and a reunion with Selleck and Larry Manetti on an episode of 'Las Vegas' in 2007. Mosley had a role as the partner of Ray Liotta in the big-screen thriller 'Unlawful Entry'