When postwar movie directors went looking for a gritty location to shoot their psychological crime thrillers, they found Bunker Hill, a neighborhood of fading Victorians, flophouses, tough bars, stairways and dark alleys in downtown Los Angeles. Novelist Raymond Chandler had already been there exploring the real-life "mean streets" that his hardboiled detective, Philip Marlowe, prowled in the writer's exacting prose. But the biggest crime was going...