 Yeah, the shooter's father called local police after the shooting, according to law enforcement sources. Now, CBS News doesn't have details about the nature of the call or exact timing, but we know the family is cooperating with federal investigators, according to the FBI. The FBI also saying the gunman using an AR-15 style rifle that shot 5.56. And just for perspective, this is the same ammunition the U.S. military uses in small arms firearms.