No doubt there is police brutality and over reaching in practice. That doesn't erase lawlessness and brutality within the community.
Precisely. The few morons who took advantage of the situation to loot some stores, just gave racists their opportunity to suggest that black people deserve to be treated brutally.
It is, as PureX suggests, a Rorshach test. Racists focus not on the homicide, but on the idiots who became violent in return. Extreme libertarians see police as an occupying power completely out of control.
Neither of those ideas are rational; they are merely projections of one's own emotional difficulties.
The first order of business is to get to the bottom of the killing and see that justice is served. The second thing is for the police department and the black community to deal with the thugs among them.