The ability of Brother's Keeper to deal with so many different subjects -- problems of the elderly and mentally challenged, the debate over mercy killing, the shifting definitions of community -- is its greatest strength. Because there is a trial for murder at the center of this story, the film is also about the limitations of our justice system to deal with acts that fall in a gray area that borders on criminality. Delbert Ward may have helped his older brother Bill to die, but given the circumstances -- Bill's debilitating illness, Delbert and his brothers' inability to administer proper care, and their extreme sense of isolation -- passing legal judgment on the act is almost impossible. The film is most provocative in depicting the attitudinal shifts the citizens of Munnville, from indifference and even suppressed hostility to the Ward brothers to passionate defense of them as fellow citizens of a rural community that prides its being removed from the rest of the world. Would residents of an urban apartment building rally around their neighbors with the same kind of antipathy to outsiders? Brother's Keeper is that rare documentary that raises questions without definitively answering any of them.