Michael Apted’s documentary Incident in Oglala lacks a screenplay because the film splices together a series of interviews and archived footage to produce a somewhat coherent conversation between the interviewees – attorneys, AIM members, Leonard Peltier, and politicians among other people involved with the case. While the director takes liberties with the soundtrack, aerial land shots, and still images, the only scripted parts of the film involve brief re-enactments and Robert Redford’s narration. Neither of these techniques get credited to a screenwriter or noted as inspiration from a text, but some sources believe that Peter Matthiessen’s book In the Spirit of Crazy Horse lead to the film’s creation. After the film’s release, Matthiessen edited sections of his book to more closely reflect the documentary and call for another trial for Peltier.