From what I can gather of the facts so far...

Darren Wilson isn't guilty of anything.  But we may not be in complete possession of all facts.

Some facts are disputed.

Here's are some relevant facts

1. Someone matching the description of Brown was videotaped robbing a store
2. The altercation outside the police car is not disputed
3. Brown's body was located several feet from the police car, which indicates a chase.  The chase is not disputed.

The officer had probable cause to stop Brown.  Brown did not have any cause to strike the officer at all.  As for the chase, Brown is not supposed to flee from a scene when ordered to halt by a police officer.

The one question and only question here is if Brown was trying to surrender at the moment he was shot.  Based upon what information exists, this does not seem likely.  Unless something unusual appears that would change this impression, there can be no charges against Wilson.

Usually, if the Feds take up a case, they don't lose it.  Now, if they take up this case and lose it, what's next?

I'm thinking this is unfortunate, but understandable in light of the probability that the people stirring this up don't care about the black people.  If black folks woke up and saw this that way, there may be some serious reevaluation of their political loyalties.  But that is probably being way too optimistic.  If I may be so bold, I think the situation has stirred up in order to keep the black folks in line.  This is not being done by white people.