It's a simple solution, and one early experiment seems to show some positive results.
Realto, CA has attached video cameras to it's officers in an attempt to reduce the unnecessary use of force and complaints associated with that abuse of power. Abuse of power has reached epidemic proportions from the federal level all the way down to the locals. It must stop.
I would take the process one step further and require all the footage to be available to the public 24/7 on the web. I'd also look for a volunteer group to review the video from all personal interactions between officers and the public for say two years, then cut back to just interactions that resulted in anything more than a simple citation. Why? simple, I want the sheep to have some control over the wolves - we've seen what happens when the police police themselves - it's rarely justice for the public.
Privacy concerns need to be addressed before any video is made available to the general public. I would want the non-officer identity protected - blurred images, names redacted from the sound track. The police, as a public employee don't get a claim on privacy when operating in the public. The original versions must still be available. I'd be will to say that only video covering contacts that resulted in a complaint by the public should make it to the web, just to save costs.