He was all prepared to shoot an intruder -- Uh oh...

http://www.rawstory.com/rs/2012/07/23/cop-shoots-son-dead-after-mistaking-him-for-intruder/

Gun enthusiasts/NRA members will have an excuse regarding this terrible incident...such as "accidents will happen" -- It wouldn't have happened if the man didn't have a gun.  He'll have to live with this "accident" for the rest of his life.