Just a theory: They could know his name. They could know it very well. Could be the antifa spawn of someone in high places, and they can't very well just go and arrest Senator So and So's(D) son, now can they? OR it could be a deep state asset. They never get arrested either.
Remember the curious case of the Las Vegas shooting, the largest mass shooting in US history? It was in all the papers ... for a week or so and then it has never been mentioned again. Weird guy with some shady international connections and wife and all that, remember?
He paid the price but it sure interesting how incurious the government has been about him and the press too.
Google Tim Kaine’s son. He’s a known agitator in Mpls.