Rioters and looters should be shot by those whose person, property or lives they threaten.
Until one of these big city mayors and police departments stand up to these criminals the riots and looting will continue.
The mayor and police need to release a statement to the press, we will not tolerate looting or violence or the closing of public highways. If you try to loot or commit arson YOU WILL BE MET WITH DEADLY FORCE and then do it. Obama and the feds would have a crap fit but then again they are not burning down DC.