The Thin Blue Line (1988 D: Errol Morris, W: Errol Morris)
Investigating the case of Randall Dale Adams, a drifter sentenced to life in prison for a murder that, the movie contends, he didn’t commit, The Thin Blue Line is gripping, stylized filmmaking. Using interviews and iconic imagery re-enactments, like the visual of a milkshake flying through the air after a cop is shot, Morris digs deep into the story. Philip Glass’ gorgeous score underlines the film. It’s a compelling tale, and after the film was released, Adams’ case as re-opened and he was released from prison. I don’t know if this is, specifically, the “best” documentary film, but it got a guy out of a life prison sentence, so that must say something.