One general point.
The US often seems to focus on individual cases and simplifies motives. White officer, black victim, must be a racist cop.
For me, while this may be true in some individual cases, the problem of violent cops mostly derives from a society that is dangerous. Because of this, police rules of engagement are harsh.
So why is America dangerous?
For me, it's because the way the US has decided to be is brutal. Gross inequality is fine for the extremely rich and miserable for the extremely poor. A lot of people are desperate. Gun rights mean that many people are armed. Because many people are armed and desperate, policing is risky. Harsh police methods make things more tense. Mistakes get made. On the margin, people die.
Chauvin is many cops on that margin. Some cross it. Some find themselves defending the Capitol.
Violent incidents involving the police are going to continue unless American politicians redefine the way US society operates. The underlying problem isn't Chauvin or the poor fellow he killed. Their story is a symptom of the disease. It's the way people live in the US which results in the ridiculous murder rate, dirt poverty and terrible ethnic tensions.
You don't fix the issue by hating Chauvin or putting him in jail, even if that is the just outcome in this case. You fix it by reducing gross inequality and by limiting access to lethal weapons so that harsh police operating procedures are no longer needed and the underlying tensions evaporate.
Even after that, there will still be bad policemen and also dangerous people. But with fewer of them, and the margin in a different place, their motives will be plain to see.