Sean Penn as Jimmy Markum

Tim Robbins as Dave Boyle

Kevin Bacon as Sean Devine

Laurence Fishburne as Whitey Powers

Marcia Gay Harden as Celeste Boyle

Laura Linney as Annabeth Markum

Kevin Chapman as Val Savage

Tom Guiry as Brendan Harris

Emmy Rossum as Katie Markum

Spencer Treat Clark as Silent Ray Harris

Andrew Mackin as John O'Shea

Adam Nelson as Nick Savage

Robert Wahlberg as Kevin Savage

Jenny O'Hara as Esther Harris

John Doman as Driver

Cameron Bowen as Young Dave

Jason Kelly as Young Jimmy

Connor Paolo as Young Sean

T. Bruce Page as Jimmy's Father

Miles Herter as Sean's Father

Cayden Boyd as Michael Boyle

Tori Davis as Lauren Devine

Jonathan Togo as Pete

Shawn Fitzgibbon as Funeral Director

Will Lyman as FBI Agent Birden

Celine du Tertre as Nadine Markum

Ari Graynor as Eve Pigeon

Zabeth Russell as Diane Cestra

Joe Stapleton as Drew Pigeon

Susan Willis as Mrs. Prior

José Ramón Rosario as Lt. Friel

Tom Kemp as CSS Tech

Charley Broderick as Medical Examiner

Lonnie Farmer as Lab Technician

Celeste Oliva as Trooper Jenny Coughlin

Bates Wilder as Loud Mouth Cop

Douglass Bowen Flynn as Cop at Barricade

Bill Thorpe as Neighbor at Barricade

Matty Blake as Cop in Park

Ken Cheeseman as Dave's Friend in Bar

Scott Winters as Detective

Thomas Derrah as Headstone Salesman

Jim Smith as Reporter

Patrick Shea as Handcuffed Man

Duncan B. Putney as Solicitor in Car

Ed O'Keefe as Communion Priest

Dave Zee Garison as '75 Police Officer

Michael McGovern as '75 Reporter

Bill Richards as Helicopter Pilot

Michael Peavey as Helicopter Pilot

John Franchi as Bar Patron (uncredited)

Colleen Kelly as Boston Cop (uncredited)

Eli Wallach as Mr. Loonie (uncredited)

Kevin Conway as Theo (uncredited)

Frank Ridley as Police Detective (uncredited)

Kris Williams as Spectator (uncredited)

Jillian Wheeler as Sara Markum (uncredited)

Lance Norris as Bartender (uncredited)

John Zaffis as Casino Patron (uncredited)