Many of the verbs used in the Judicial Watch reportage (I went to their site since they are the origin of this story, not the OP link) are questionable. For example, JW claims the CRS was sent to "train" the protestors. However, I see no evidence of that. The CRS acted as mediators in a very tense racial situation, and if that prevented the protestors from going into full riot mode, that is hardly what I would calling "training" them. Except in the sense of training a dog to be obedient.
What I do have a problem with is the federal government getting involved in a local level problem to begin with. Local governments have mediators for this kind of crap. The DOJ is way, way, way outside their jurisdiction, and probably used the thinnest of "civil rights" excuses to insinuate themselves into the situation.
I believe this is because Obama opened his big yap and adopted Trayvon Martin as his son. From that moment forward, those who hate Obama wanted to see Obama's kid convicted as a drug using thief and thug who deserved what he got, while those who like Obama wanted to see Zimmerman go to prison for murdering Obama's kid.
If Obama had simply refused to take the media's bait and just said he deferred the matter to whatever the local authorities determined about the matter, that would have been the last day any of us even heard anything more about it. And the DOJ would have stayed in DC where they belong.