Prior to acting, he had worked as a doorman and a stand-up comedian. While working at the Boston Office of Cultural Affairs, Chapman was discovered by the late director
Ted Demme and was cast as Mickey Pat in
Monument Ave. (1998). Other notable film roles of his include
The Cider House Rules,
Mystic River,
21 Grams,
In Good Company, an Italian mobster in
The Boondock Saints (1999), and Fire Lt. Frank McKinney in
Ladder 49 (2004). Chapman starred as
Irish Mob boss, Freddie Cork, for three seasons in the
Showtime original series
Brotherhood. Chapman played a first responder assisting Jack Bauer (Kiefer Sutherland) in season 1 episode 24 of the TV series
24 (2001) and Kevin Mitchell in
season 3 of
24 (2003). He also played a CIA operative (O'Leary) in the independent comedy
Black Dynamite. In 2006, Chapman appeared as an officer in the episode "
Lessons Learned" (Season 2, Episode 10) of
Criminal Minds. In 2010, he played Bunny in
Tony Scott's action film
Unstoppable. He also was a guest star in the series
Lost. He appears in the film
Bad Country (2013), directed by
Chris Brinker. From 2011 to 2016, he portrayed Detective Lionel Fusco on the CBS show
Person of Interest. ==Filmography==