Try talking to some. You'll be surprised that most are actually pretty good people trying to make a difference in a very difficult job. They see nothing but the worst of humanity day in and day out.
US police officers aren't bad people, they're just poorly trained and held to very low standards of accountability. They do bad things because they're operating in a system that incentivises them to do bad things.
Nice quote. Can you recommend some reading on this topic?
https://www.amazon.com/Lucifer-Effect-Understanding-Good-Peo...