If you found yourself wondering, during Kirsten Johnson’s excellent 'Cameraperson,' where the material from the James Byrd trial came from, the answer is this 2003 documentary from directors Whitney Down and Marco Williams (newly streaming via PBS’s POV site). It concerns the June 1998 dragging death of Mr. Byrd, an African-American resident of the small town of Jasper, Texas, for which three white men were put on trial, individually, the following year. The filmmakers ingeniously split up: a black crew filmed the city’s black residents, and a white crew filmed its whites. This division of labor allows its subjects talk in in something like private, revealing the complexities of their beliefs, and how deeply they’re ingrained – from the “Bubbas…