Namely, it isn't just police brutality that's the problem, but the whole cycle of violence. Yes, the officer who killed George Floyd needs to be prosecuted. Yes, the officer who wantonly pepper-sprayed protesters while driving past needs to be fired and charged. However, the riots and burning of police precincts have reinforced an "Us vs Them" mentality in the police and primed officers for the next round of brutality. Imagine that a mob of people of mostly the same ethnicity came to your place of work, threatened you with violence, and burned the place down after you and your co-workers fled. No matter how justified the mob's anger may be, this is how you create racist cops.
The riots in Minneapolis are rooted in mutual suspicion and lack of respect between the black community and police. Both sides can point to awful things the other side has done, but both sides need to be better in order to break the cycle.