Its always interesting to me how fundamentally similar Cop/public interactions are to Teacher/student interactions on a big high school campus (where most of the students are not personally known to the teacher). The big difference being of course teachers don't have the means to resort to deadly force or even hardly any force, said force such as it is employed only under rare and specific circumstances.
In the heat of the moment the fundamental error that Cop made was that he wanted to win. The perp had just won the first round involving the tazer and was getting away, so the Cop without thinking it through reached for the next object in his belt and escalated.
When me or any teacher gets into it with some kid, its natural to want to "win" too, and escalate until you do. In most such situations there's no real point; let the kid run off and evade, it ain't like you can't find out who he is and get him tomorrow or next week whatever.
Likewise, this victim was hardly anonymous, most likely the usual steps had been gone through for a regular traffic stop, and even if no ID had been obtained, surely the car would prob'ly do it, one way or another.
JMHO, Birdwatcher
"...if the gentlemen of Virginia shall send us a dozen of their sons, we would take great care in their education, instruct them in all we know, and make men of them." Canasatego 1744
