The killing of Michael Brown by a police officer has reignited the national debate over whether police should all wear body cameras, designed to record their every move. One California city saw a 60 percent reduction in use-of-force incidents in the first year it deployed the cameras. Los Angeles has been doing small-scale experiments with the cameras, but has yet to roll them out across the board. We look at where else they’re being used and the civil rights questions they raise.