Well, this pretty much assures that Wilson will never go to trial - regardless of the evidence (which, IMO, so far favors a justifiable shooting), there’s no way the court could find an untainted jury pool.
On a criminal charge, anyway. You can bet they're planning a federal civil rights charge, and they actually don't want a criminal trial because they know Wilson would be acquitted, as was Zimmerman. If there are no charges and no trial, the pressure for federal action will increase, and that's what they want. They want more riots and more looting and more minority outrage.