Then America needs to look at why it has a whole bunch of angry people prepared to jump on the looting bandwaggon. I'd argue (because I'm a socialist) that America needs to invest a little more in its frontline social work services and a little less in it's comprehensive prison syste, - so that people like Rosenbaum can be helped before they become as problematic as he undoubtedly was. What you're seeing here is the behaviour of a nihilist, someone so angry at the way they've been treated that their default is violence.
Progressives see this as an opportunity for bashing the right for their gun happy approach to policing. Current laws favour Rittenhouse and the self-defence argument - but politicians should take a more holistic view of this and wonder what sort of society erupts into violence at the drop of a hat. It's evidence of a broken state in need of overhaul, not the isolated actions of a single set of malfeasants.