I am religious, albeit not to an extreme extent, and things like these are just that: unintended. Religion is not in the power to stop them. Or maybe it's a test of faith to the victim's family and friends. Plus, if he was genuinely religious, he shouldn't have attacked him in the first place.
Reminds me of an account from the ancient Olympics concerning a boxing match. If I remember correctly the rules were that each fighter would take turns punching one another. One of the fighters reportedly fatally struck his opponent so hard as to lodge all five of his fingers into the man's chest. He lost the match on a technicality. The judges deemed the attack to be five blows.