
I can't find where I read it, but I saw an article on what the jury makeup is for the grand jury that's hearing the evidence in the Michael Brown shooting: three black people, nine white. They say that it is representative of the racial makeup of St. Louis County, not neccesarily the racial makeup of where the crime took place.
There's two important things here. First, grand juries review evidence and decide whether an indictable crime has happened, they hand down the indictments that charge a person with a crime. They're empaneled for a period of weeks or months and review lots of cases but they are not the ones that decide guilt or innocence. Their term ends at the end of August but it looks like they'll be held over in to September in case they can't review all of the evidence of the Brown shooting, rather than start all over again with a new jury.
Second, when and if a trial happens, the defendent's case is heard by a jury of the defendent's peers, not neccesarily the victim's peers. This happened in the Rodney King beating when the officer's trial was moved up north from LA, and IIRC, an all-white jury was empaneled. There was a huge backlash of people complaining that there were no (or few) black people on the jury.
The thing to remember is that our legal system is based on two things: presumption of innocence beyond a reasonable doubt and a trial by a jury of your peers. It's not perfect, but it's pretty darn good. And there's always recourse to civil trials when criminal trials do not produce justice, and there's also Federal trials for depriving someone of their civil rights.
I don't think that Michael Brown's death can be justified, nor should it go unpunished. But we don't have all of the evidence, and we'll just have to wait to see how it plays out in the courts. I think it's a lot more clear in the shooting death of the knife-weilder as we have video that shows the shooting, and it clearly was not a justifiable death. Again, we'll see how it plays out in the courts.