Do the police ever kill some of those "battle-ready" private citizens standing in a group?

I agree completely. Cops should brutally suppress criminals of all races by whatever means necessary.

Part of this is likely the reemergence of a “warrior class” in American society. Young men are raised in patriotic households, told that serving and dying for your country is the highest possible honor, and then head overseas to fight in America’s wars. They return home and join law enforcement or otherwise join security positions and then raise families with the same values, who continue the process. We are reaching a point - which, for what it is worth, it not at all atypical historically - where the people who secure our physical wellbeing are culturally and even genetically from those they protect. A large part of this process, I would wager, has resulted from the progressive stigmatization of law enforcement, the military, and masculinity, discouraging all but those thoroughly ensconced in traditional values from entering into these fields.