Yeah, I kinda did get off subject didn't I? Nonetheless, the principle is the same; a police officer should be present to observe and report. At some point immediate to the alleged infraction there needs to be human intervention. Perhaps someone who ran the light was transporting an injured person for medical care and they ran the light in a prudent, safe manner.
Looks like another thread supplanted it.
Still, you haven't addressed the question of how it is that liberty is extended by putting an armed cop on every street corner.
No doubt 'tis a mystery, eh?!