Michael Apted's documentary is an investigative report on the case of Leonard Peltier, an American Indian Movement activist who was convicted of killing two F.B.I. agents in a 1975 shootout on the Pine Ridge reservation, in South Dakota. The movie contends that Peltier (who has been serving time for the murders since 1977) was railroaded by the F.B.I. The filmmakers don't require us to believe that Peltier is innocent (although they clearly think he is). They concentrate on demonstrating that he didn't get a fair trial: the movie is built on an accumulation of subtle discrepancies and nagging doubts, rather than on a sense of inexorable progress toward a smoking-gun solution. For the most part, Apted guides us through this tangle of ambiguous evidence and back-and-forth legal maneuvering with patient, unobtrusive skill, and the cool rationality of his manner makes the movie's arguments seem all the more irrefutable. The picture never tries to whip us into a frenzy of indignation, but its restrained, lawyerly laying out of a pattern of injustice is devastatingly effective. Narrated by Robert Redford (who is also the executive producer). -Terrence Rafferty