David Fincher Director Jake Gyllenhaal Robert Graysmith Actor Mark Ruffalo Dave Toschi Actor Robert Downey Jr. Paul Avery Actor Anthony Edwards Bill Armstrong Actor Dermot Mulroney Capt. Lee Actor Brian Cox Melvin Belli Actor Elias Koteas Jack Mulanax Actor Donal Logue Ken Narlow Actor John Carroll Lynch Arthur Leigh Allen Actor Clea Duvall Linda Ferrin Actor Chloë Sevigny Melanie Actor Ione Skye Kathleen John Actor Tom Verica Jim Dunbar Actor Charles Schneider Paul Stine Actor Jim McNichols Bill Hamlet Actor Pell James Cecelia Shepard Actor Adam Goldberg Duffy Jennings Actor John Getz Templeton Peck Actor Zach Grenier Mel Nicolai Actor John Hemphill Don Cheney Actor James Vanderbilt Producer Mike Medavoy Producer Arnold Messer Producer Bradley J. Fischer Producer Ceán Chaffin Producer Louis Phillips Executive Producer Harris Savides Cinematographer Angus Wall Film Editing David Shire Original Music Donald Graham Burt Production Design Keith P. Cunningham Art Director Victor J. Zolfo Set Decoration Casey Storm Costume Design Laray Mayfield Casting Robert Graysmith Screenwriter