Your statement: " lots of major cities are still White Boys Clubs, police unions are bastions of corruption, racism is the norm," - is false, and almost bigoted.
The vast majority of PD's in America, the Police themselves generally reflect the racial reality of the communities they manage.
Chicago PD is about 50% White, 25% Black, and 25% Latino. [1] Black and Latino police are overrepresented those forces. This is not uncommon.
Why don't you have a look at the actual data - all the PD ethnic composition is right there for you to see.
It's false to suggest that these PDs are 'a bunch of White Boy Clubs' - when they literally are not, but not only that, just the opposite, fairly multicultural and excellent examples of 'functional diverse workforces'.
Ironically, the police are considerably better than hight tech at demonstrating how representation and getting along matters.
The fact that Police forces generally well reflect the ethnicity of the people they manage is probably something most people wouldn't necessarily know, and it's 'real-world information' that adds nuance to the situation. Unfortunately, since this reality doesn't fit the narrative, it doesn't get talked about.
Even this incident in Minnesota: we have 'assailants' who are diverse: two white cops, an Asian cop, and a cop 'of Colour' (possibly Black?) - does that fit the 'Team Racist Redneck' narrative? No.
It's ridiculous to suggest 'racism is the norm' on teams that are overwhelmingly diverse, wherein partners, managers, chefs, officials are of every stripe and creed. Also, it's kind of insulting.
So how could it be that people have this view of PD's when the data shows that this would be highly unlikely? Why is this kind of information not made part of the discussion on various media outlets? There's a lot more where this came from.
Populism leads to misinformation, poor analysis, and crude thinking. The situation is far more nuanced. We need dispassion and reason.
[1] https://www.governing.com/gov-data/safety-justice/police-dep...
Chicago is 32% non-Hispanic white, 32% black, and 28% hispanic. So, no, white cops outnumbering black cops 2:1 is not black cops being overrepresented. (This is as of the latest census.)