if you want to have a discussion as to how to weed out the bad apples Im all for it
if on the other hand you feel most cops are racist then we have nothing to discuss
It's hard. Think about this: many of these issues occur in big, liberal cities. Minneapolis is very white, but even Minneapolis is a somewhat liberal city. Eric Garner occurred in NYC. Rodney King occurred in LA. Which suggests that something MUCH bigger than racism is involved.
Why do these liberal cities not fix the problem? While, one issue is public sector unions. The police union tries to make it impossible to discipline cops (which of course, as a union supporting their members, makes sense) because they want to ensure discipline is fair. In reality, they create so many hurdles to jump through that discipline is near impossible. There's a reason that being put on "paid administrative leave" is such a cutting joke about bad cops when they do something legitimately heinous enough to be investigated. Because the unions made it hard to just fire someone for being a bad apple. And the liberal cities are full of politicians that are pro-union [and receive union campaign donations], so they realize their careers might be cut short by opposing the police union.
Individually, I think the good cops know that speaking out against their colleagues, largely for the reason above [near-impossible to actually discipline anyone and get rid of them], is ineffectual. They also know that they're on a team with the rest of their department. The minute their colleagues believe that he's not going to have their back,
they're not going to have his. And it's usually easy to rationalize not speaking up, of course, because while the bad apple might have gone too far, the victim of the abuse wasn't exactly a "good guy", he was a criminal. So it's easy to just shut your mouth and not rock the boat. And over time, that jaded position becomes the norm inside a department.
District attorneys are generally political positions as well. They're the ones tasked with charging criminals, so when a police brutality case is brought before them to charge or not, they realize they have the same structural incentives as city politicians: don't piss off the constituency that is pro-police, don't piss off the union kingmakers who can fight against you in the next election, don't piss off the police who can engage in subtle harassment of you and your family because you prosecuted one of theirs.
That circle of the venn diagram reads "the police system is structurally corrupt and regularly refuses to prosecute cops"... I believe that to be true for the reasons above,
even though I don't believe that most cops, DAs, or politicians themselves are corrupt. That's where the
structural corruption comes in. It's a system that takes in mostly good people, and ends up with bad outcomes.