Carmack's starred in The O.C. from 2003 to 2004. He played Luke Ward, Marissa Cooper's jealous and brutish boyfriend. Luke's arc throughout the show is full of twists and turns, like his engagements in scandalous affairs and his discovery of his father's sexuality. Some fans may have felt a tinge of resentment towards him for beating up Ryan in the first season, but Luke turns out to be a mostly decent guy towards the end. Mostly.