Exactly what do the protestors want? Do they want to reform the whole policing system, the justice system or want more transparency? The point is people protest will no actual aims, they protest because they see things as unfair, but you know life is unfair at times. there are ways to resolve issues, but they need to have a plan of what can work and is reasonable. Besides this, in the US state laws vary so there will always be differences.
From what I know, they want the cops who killed Mike Brown, Eric Garner and all the others who suffered from the hands of the police be indicted. But it's basically the judicial system they are after now and it is going to be a long shot before they could just change the minds of the judges like that.