Two weeks ago in France, 2 policemen were sentenced for beating up students. This kind of conviction is extremely rare, but they were caught on CCTV beating up "for fun" two students that were walking back home. It was probably a racist beating, since they first attacked the colored guy. Their sentences were symbolic. Both are still policemen, and one of them has been promoted. https://www.lefigaro.fr/flash-actu/prison-avec-sursis-pour-d... (in French)
De facto, policemen are above the law. And of course, many of them abuse that system. Yet most people don't care. They want law and order, even if the law is not the same for everyone, and even if the order is not just, and sometimes criminal.