Ken Burns's documentary “The Central Park 5” (it was co-directed with Sarah Burns and David McMahon) begins with the recounting of the rape of a jogger in the park during April of 1989, the trigger event of a woefully tragic story. Working with his daughter and son-in-law, Burns has created a nearly flawless film about the cracks in our criminal justice system, zeroing in on the “us vs. them” mentality that became