From what I see, one officer killed the man being arrested and should be taken before a fair grand jury, likely correctly charged with manslaughter or even possibly 2nd degree murder, depending upon many fine details we simply do not and can not know.
The protest is entirely legitimate in my opinion. It is not rare that police get away with murder where anyone else would not. The protests prevent the police department and district attorney's office letting this quietly go away, to pressure the grand jury into no billing and/or the district attorney over charge all 4 and present a terrible case so they are all found not guilty - highly motivated to do so since the city is being sued for $50 million dollars and guilt proves absolute proof then in a civil lawsuit.
The looting? Those are opportunistic thugs. While racist was likely not the cause - rather general police brutality and maybe economic bigotry (police far more tend to beat up poor people in general seeing them as social trash) - I don't know that it wasn't.
The looters should be dealt with harshly, arrested if possible and shot with red paint balls to identity them for arrest later and proof of guilt. The protesters, as long as non-destructive or violent, should be given a wide berth to allow them to protest, to have their voices heard, to show their determined solidarity, to collectively mourn the death, and to emotionally vent - ie exercise their constitution right to organize and protest what they see as unjust conduct or wrongful inactivity by their government officials.
