It stars Gene Hackman as surveillance expert Harry Caul who faces a moral dilemma when his recordings reveal a potential murder. Supporting cast members include John Cazale, Allen Garfield, Cindy Williams, and Frederic Forrest. Harrison Ford and Teri Garr appear in credited roles, and Robert Duvall in an uncredited role. Mackenzie Phillips, who had just worked for Coppola on American Graffiti along with Williams and Ford, had a supporting role as Harry Caul's niece that was dropped during the film's editing stage. Likewise, Abe Vigoda's role as Caul's lawyer also ended up on the cutting room floor.