Since retiring as a Navy SEAL, Kyle had been actively helping other military veterans recover from PTSD....(There's a video interview with Kyle at that last link.)
While serving in Iraq, insurgents placed a bounty on Kyle's head because of his lethal accuracy as a sniper. He recounted his experiences in "American Sniper," published last year.
February 3, 2013
Chris Kyle — "The Most Lethal Sniper in U.S. Military History" — shot point-blank at a firing range.
The suspect is an ex-Marine — Eddie Routh — who is said to have post-traumatic stress syndrome.