Police arrested a Georgia teacher for firing a gun at school, just days after President Donald Trump ignited a national debate over whether some teachers should carry weapons to protect their students. No one was injured at Dalton High School except for a student who injured an ankle while running, police spokesman Bruce Frazier told CNN. Police identified the shooter as social studies teacher Randal Davidson, 53, who surrendered at the scene. One Dalton student tweeted to the National Rifle Association: “my favorite teacher at Dalton high school just blockaded his door and proceeded to shoot. We had to run out....