A potent and highly engrossing documentary by Joe Berlinger and Bruce Sinofsky about a 1990 murder trial in New York State that attracted national media attention. The case involved the death of one of the four illiterate Ward brothers, all reclusive and eccentric bachelors who inhabited a two-room shack without running water on their dairy farm. Bill was found dead in the bed he shared with Delbert, who confessed the same day to suffocating his ailing brother in a mercy killing, but later retracted his confession and implied he was being framed. It’s amazing how many primal issues are engaged in this real-life mystery story, and Berlinger and Sinofsky, who contrived to follow the story from start to finish, do a superb job of keeping us on the edge of our seats (1992). Music Box, Friday through Thursday, March 26 through April 1.