Sacha Jenkins’s Burn Motherfucker Burn starts making connections right away, coming out of the credits with one of (too many) contemporary analogues for the King video: the 2015 cell phone footage of L.A. cops murdering unarmed African-American Charly “Africa” Keunang. From there, we’re bounced back to a distant counterpart, the harrowing story of the April 1962 police shooting...