There was a cop in Pittsburgh that pistolwhipped and shot some random that he thought mouthed off to him after leaving a bar. No charges, wasn't fired, took nearly twenty years of repeated incidents to get rid of the guy.

 
https://www.pghcitypaper.com/pittsburgh/controversial-pittsburgh-police-officer-paul-abel-reportedly-off-the-job/Content?oid=18536399

 
They wield the real power in our cities and they're quite open about how untouchable they are.