For 80 minutes we sit, palms choking armrests, as a flashback to boyhood explains the motivation behind the youthful American sniper (Nick Krause), alone in a car, one eye blackened and rifle cocked, who opens the picture. White Rabbit makes Bully (well-intentioned indie doc, not Larry Clark’s good time) look like an Our Gang comedy in its naturalistic — give or take a few psycho-interactive comic book panels — not-based-on-a-true-story (!) account of an acutely sensitive teen whose life of bad influences eventually leads to a high school shooting safari. Director Tim McCann and screenwriter Anthony Di Pietro don’t exactly sidestep all of the cliches inherent in the material, but their combined eye for horrifying (yet absolutely right) character detail make for a much richer experience. The cast of relative unknowns, matchless across the board, keep it fresh. On a sour note, the score — an endless fermata backed by scratchy vinyl — is torturesome. (2013) — Scott Marks