Christopher Williams believes that one little box changed the trajectory of his life. Williams has been to prison more than once. When he was inside, he tried to prepare himself for the outside, for a chance to move on from the thing for which he’d done his time, by participating in job training programs and GED classes. But when he got out, that box — the box on job applications that asks if the applicant has ever been arrested or convicted of a crime — stopped him in his tracks.