You use police brutality in the question, and in respect to that, probably, yeah. I’m sure police officer action is, indeed, investigated and all, especially for something serious, like a shooting. It was mentioned up above. But there’s probably a load of stuff that they get away with, that they shouldn’t be doing. Maybe it’s minor, but it’s still needless, and is still brutality. I’m sure major stuff goes unpunished, too. Probably that a lot of stuff goes unreported…and even if it does get reported, you might need a good lawyer, unless there’s millions of witnesses ready to cover. :/
So if absolutely everything did have to be justified in accordance to what a cop can or cannot do in whatever given situation, brutality would greatly diminish.
Although police brutality happens, most cops are peeps paying the rent like everyone else, so whether or not lots of them bend the rules or abuse power, the ones that do would stop, (or justify it if they can) if they still want their job.
Not really related, but I saw a documentary on the net a few days ago about the ten worst prisons in the world. Most are bad because of how prisoners get treated. One prison in Turkey even jails small kids, and they’re expected to get the same treatment as adults. Gah. Therefore, I also wonder how different prisons would be if wardens and guards had to justify themselves for what they do to inmates.
Just that example to say that, as far as people with authority goes, there’s probably a shitload of stuff that wouldn’t be happening if power was not abused. I also wonder if I’d own so many ketchup packets if I had to explain why I keep stealing them from my work place’s cafeteria. XD