I see it more as the ancient equivalent of disabling a car alarm when you're stealing it. They were robbing the graves not preforming a ritual. Their beliefs ma

I see it more as the ancient equivalent of disabling a car alarm when you're stealing it. They were robbing the graves not preforming a ritual. Their beliefs may have been supernatural but at the time it seemed logical to "kill" the observer of the crime. It wasn't defacement to send a message, it was practical and tactical as far as the robbers were concerned (according to this article's premise).