As long as the police are on the same team as the prosecutor, then they are above the law. The police, as "peace officers" should be held accountable by special prosecutors convened by citizen panels. Those citizen panels should also be very visible and should report their findings on a regular basis, not just for high profile cases, but all cases.
As long as complaints of police brutality disappear inside the system, everything else is just window dressing, even though some of that window dressing (like cameras on cops) is probably pretty useful.
I'd like to see that proposed just to see the screaming the police unions start doing. I'd bet good money that police start going on strikes before they would allow that to happen.