Grand Jury Finding

I find it hard to believe that the Grand Jury found that there was not enough evidence for a trial in the State of Missouri v. Darren Wilson case. Even after only reading my own section I felt that there were a lot of unanswered questions, but then when I listened to the other 3 presentations in class I realized that there are a lot of questionable things going on in this case. It doesn't make sense to me that Darren Wilson would be so aggressive towards someone who was just walking in the street, let alone shoot them 6 or more times. Even the nature of the shots should be enough evidence for a trial, Michael Brown suffered 3 fatal shots, aside from the rest, after putting his hands up to show he was unarmed. Officer Wilson's reaction to this situation was clearly out of line, causing the death of a young boy. Whether it is racism or something else, there is clearly something else going on here that has yet to be revealed. I realize that there are a lot of more volumes to go over so perhaps these questions will get answered later, but at this point I just don't understand why this wouldn't go on trial.