No, they have already arrested several blacks and are looking for more.
Yeah, the cops will move aggressively on this. Otherwise the Bosnian community will ... and the Black community will get a very painful lesson that some other cultures actually, based on hands-on experience in much worse conditions, do the ethnic/sectarian strife thing MUCH better than they do.
Holder's probably already been on the phone to the D.A.'s office to make sure the perps only get a slap on the wrist.