Inspired by Curtis' thread, and to not hijack that. Some thoughts.
It might be an interesting sociology study to try to determine the actual ratio of good v bad, in the context of current events. We don't ever hear stories of good cops, and we can only assume otherwise that the bad ones are only a few. My Wife thinks I'm silly for thinking that the TV show called The Rookie, which we've been watching, isn't a public relations vehicle to promote the idea of the mythical good cop.
The reason it is likely that ACAB is more true than we'd like to think, is that there is plenty of evidence that the cops on forces all across the country self-identify as a brotherhood. They get actual training in the things that we civilians would consider bad cop behavior. Like being trained to join fellow cops on scene, and unload an entire magazine from a handgun when some one of them determines the person involved is a perp and a suspect and is doing something like resisting or evading. People who get on a force and see that, are maybe as likely to join in as to be revolted and quit for a job in some other field. Self-selected bullies with all sorts of daily reinforcement as to their privilege to unleash force on strangers at the drop of a hat.
Which is why my recommendation would be not just some form of 'defunding' or changing the workload of cops such that other types of social workers can answer some of their current work load. I think what we need is a total revamping of the cop system, a re-working of police training and equipping, and I also think a nation-wide, force by force, precinct by precinct purge of current cops. Reinvent policing and hire completely new, non-brotherhood indoctrinated people to be the bulk of the new cop forces, everywhere.
Make the new cop wear some other kind of uniform than black, and military looking. Make them use, like Barney Fife, side-arms with a single bullet. Make them need to rely on the taser or some other non-lethal instrument. Make them ride with a non-uniformed sociology trained person who is unarmed but has seniority in a given situation. Make every allegation of police abuse of power be investigated by non-professional non-LEO civilians. And make every cop who is found to have abused the authority of force be immediately fired and subject to criminal prosecution. Every time.
Even if ACA are not B, it is a prevalent meme and POV in our society, and the feeling the communities have isn't arbitrary or unearned.