What has happened is a justified protest that turned into a riot where there has been many shots of folks walking away from shops with beer and TV's. The justifiable portion has now been completely lost.
I look 25-30 miles north of me where I see riots and destruction in Atlanta. Why Atlanta? A black run city, the mayor, the police chief, most local judges, the city council is majority black, the police force is majority black. Yet riots and looting in Atlanta. Is this racial injustice? If so it's blacks against blacks, in Atlanta anyway.
The Atlanta police force had nothing to do with Minneapolis. Neither did the entire city government and justice system of and in Atlanta. But back to the question, should whites speak out? I don't think it would do any good. The King family has spoken out in Atlanta, so too the black mayor and black police chief, it didn't do any good. If the rioters and looters won't listen to them, they sure as heck ain't gonna listen to anyone white.
The sad part about all of this is the racial injustice, the police brutality has now been lost. The new story, black looters and rioters has taken over. I still don't understand why Atlanta? Unless it is perceived regardless of who is in charge, white, black, Hispanic, Asian, that those in power are corrupt and enforce the power of government on the little people.