Another Side to the Horror of War?

Ashley Guindon is gunned down on her first day of duty. She was a Marine Reservist. Her killer, Staff Sgt Ronald Hamilton is assigned to the Pentagon. He must be a very accomplished soldier and one of our 'heros' before he loses his temper and opens fire. His neighbor said he was a good guy. Was he in the war zone where human life is devalued? I would think this is more of an issue than any of us would want to admit. When we send innocence to kill and maim is it possible they return to haunt us? Is there any forgiveness for this man? Do we simply write him off as a 'suddenly developed monster' and wait until it happens again? Do we remember yesterdays headlines? Eddie Ray Routh anyone?