But what is a 'bad' cop? What would 'ratting' out another cop even mean?
For me a 'bad' cop is the same thing as a 'bad' individual. It's someone that has infringed upon another individuals life, liberty, or property. But it's worse when cops are 'bad' since cops aren't held to the same level of accountability as a normal person. If I go out and shoot up some cops wife and daughter in their pickup truck I get arrested(or worse) and go to jail but when cops do it they get a taxpayer funded vacation from work for a couple weeks while other taxfeeders(Internal Affairs) do what they can to make sure the offenders are never held accountable.
So I see no way of fixing the problem with 'bad' cops till you take away their ability to initiate harm against an individual that has harmed no one. And cops must be held to the same standard when it comes to accountability as the rest of us individuals.