Sadly, knowledge becomes liability. If they just plod forward with what they want to do while internal investigations usually clear officers of any wrongdoing, they’ll always come out on top.
I used to work in law enforcement as a dispatcher over ten years ago. The amount of drinking and cynicism and apathy necessary to do those jobs was all I needed to see to get out. There were some good people, but they weren’t as dominant as the Super Trooper asshole cowboys who did what they wanted.