The roots of Steve James's disturbing documentary lie in youthful idealism: As a student at Southern Illinois University in the mid-1980s, he became a Big Brother to Stephen Fielding, an impoverished child from near-rural Pomona. A plump, thick-lipped 11-year-old with chunky glasses, Stevie had already been profoundly failed by his fractured family. By the time James graduated and moved to Chicago, 13-year-old Stevie was increasingly troubled and troublesome. James pursued filmmaking, eventually making the acclaimed HOOP DREAMS (1994), while Stevie got lost in state homes, foster care and mental institutions. In 1995, James returned for a brief, uncomfortable reunion...