Okay, so they're not all bad. We've all seen the movies and TV shows where there's a couple of honest cops who believe in the system.
However, a lot of cops tend to murder innocent people. Some cops in Baltimore put a suspect in the back of a van and drove a very convoluted way to the police station at high speeds. The guy died, and of course the cops were found not guilty.
There's lots more.
When Australian woman Justine Damond was killed by a Minneapolis cop people suddenly seemed more shocked. White woman I suppose. Can't murder them.