Originally Posted by Rochard

If a shooter is taking out innocent people for no reason, then yes, the shooter is insane. Even if there is a reason behind it - jealousy, rage - it's fucking insane to kill another person even if you are mad at them for banging your wife or some perceived slight.

Military is a bit different. The case you mentioned is extreme, but in most cases military forces close with and fight the enemy - it's something they are trained to do, and there is a proper reason for it. But then afterwards the mental issues crop up....