It looks like the prosecutor wants to side-step justice by dropping the ball with a grand jury. They say any decent prosecutor should be able to get a jury to indict a ham sandwhich, but that's only if he wants to.
I bet he is feeling the heat after the brown's autopsy expert released his results. Please remember that this is the prosecutors office where an applicant was told that she would likely hear the N-word a bit, and then asked if that would bother her.