The gunman who killed three police officers and wounded three others in Baton Rouge, Louisiana, has been identified as an American citizen named Gavin Long, a source with direct knowledge of the investigation told Reuters on Sunday. The source added that investigators also said there was reason to believe a 911 call may have been used to lure police to the shooting scene and that the possibility it had been a conspiracy was being examined. Officials speaking publicly have not yet released the name of the suspected killer or any details, beyond saying they believed it was a single shooter.