MILWAUKEE (AP) - The black man whose killing by police touched off rioting in Milwaukee was shot by a black officer after turning toward him with a gun in his hand, the police chief said Sunday, as Wisconsin's governor put the National Guard on standby against any further violence on the city's mostly black north side. Police Chief Edward Flynn cautioned that the shooting was still under investigation and authorities were awaiting autopsy results, but that based on the silent video from the unidentified officer's body camera, he "certainly appeared to be within lawful bounds." At the same news conference, Mayor Tom Barrett said a still image pulled from the footage clearly showed the gun in 23-year-old Sylville K. Smith's hand as he fled a traffic stop Saturday.