A gunman shot and killed eight people and wounded at least seven others at a busy mall north of Dallas on Saturday, police said. The gunman, whom authorities said they think acted alone and whose motive was not yet known, was killed by a police officer after he began firing outside of the Allen Premium Outlets mall at 3:36 p.m. local time in Allen, Texas, the city's police chief Brian Harvey said at a press conference. Allen fire department chief Jon Boyd told the same press conference his department took at least nine victims with gunshot wounds to area hospitals....