I hate to side with the cop, but is it really wrong of him to put it down after it has been run over several times? horses and dogs and cats all get put down when we think there is too much pain for them to handle. I'm not saying the cop has abundant knowledge of herps, all I'm saying is that the guy who ran it over was doing something wrong.
It really pains me to hear when people talk about hurting snakes, even people I know tell me about their encounters with snakes that make me cringe.
i think the cop was right for putting it down after it had been run over. but i think that the person who ran it over that many times is a jerk.