A man armed with an AR-15 style rifle and 13 ammunition magazines opened fire in an Omaha, Nebraska, Target store Tuesday before he was killed by a responding officer, police said. Omaha Police Chief Todd Schmaderer said 911 calls were made shortly before noon local time about an active-shooter inside the store, which prompted a heavy police response from local, state and federal authorities. Mayor Jean Stothert said that police saved lives by their response