What is interesting, having worked from the inside of police for 15 years, is the difference between the different state (and federal) police- some are "forces" some are services. But in all forces or services, the level of corruption can be "eyeballed" by looking at how long since they had a "Royal Commission" in to corruption. Anything longer than 25 years ie a generation, is too long.

And it's not just about bad practices- one of the things that happens in such a royal commission /bloodbath, is that police have to get off their high horse and get treated like everyone else. You know, being "joe public", humble.

Police will say - after such a public flogging "the public stopped fearing us, we had to ask people to do things instead of telling them" .. to which my quiet internal response was- of course you fool, you are a public servant, not an overlord..

once every 25 years, minimum, with some sort of independent body in-between - as what to do in those colonies that threw out the whole system and don't know what a royal commission is? (such as the USA)- I have no idea, good luck.