He attended the University of Notre Dame in Indiana.
After graduating, Roos moved to Los Angeles, where he pursued a career writing for television Roos supported himself by working as a word processor, and to this day jokes that he has that as a fall-back plan. Roos went on to write for The Colbys, Nightingales, and other television shows, before his spec scripts led to feature film writing assignments.
Roos"s work as the writer of the film Single White Female has earned him a permanent space in Hollywood movie trivia, since that title has entered the lexicon in reference to the film"s psychopathic lead character who begins to take on her roommate"s identity.
Roos has polished or written the screenplay to many high-profile studio films, sometimes as uncredited script doctor. Marley & Maine (2008) (screenwriter) Diabolique (1996) (writer) Boys on the Side (1995) (writer) Love Field (1992) (writer) Single White Female (1992) (screenwriter).
His first major film was 1991"s Academy Award-nominated Love Field, an interracial drama starring Michelle Pfeiffer and Dennis Haysbert. Roos is well known for his work writing strong and engaging female characters, a skill that has also been useful in his film direction, leading to Independent Spirit Award nominations for actors Lisa Kudrow, Christina Ricci, and most recently, Maggie Gyllenhaal. Roos himself has won a Best First Feature Independent Spirit Award, for The Opposite of Sex.