Los Angeles County Sheriff's investigators want to question singer Justin Bieber after a photographer complained of being assaulted by the pop star.Sheriff's Lt. Robert Wiard says the photographer called 911 after complaining of chest pains. Wiard said the altercation occurred when the photog was trying to get a picture of Bieber and girlfriend Selena Gomez as they exited a theater at The Commons at Calabasas.

Calls to Bieber's publicist have not been returned so far.