And they never will. I'm working my way through the third edition of Samenow's "Inside the Criminal Mind" which I highly, highly recommend. His central thesis is that criminals choose to commit crimes because they have an ill-founded sense of entitlement. He discounts all of the popular arguments for crime (poverty, racism, hopelessness, social inequity, etc) and makes the case that crime is a choice engaged in by rational actors for either personal gain or "fun." The solution is to hold people accountable and put the bad people where they can't hurt the good people.
This is the complete opposite view of reality of every socialist utopia. Just listen to all of the reasons offered for Chicago's high ag assault and murder rate. They offer every excuse except - these are bad people doing bad things. In a socialist utopia, the policeman is just an armed social worker (and they're not too sure about the armed part). Every problem can be solved with a little social justice and violence is never the answer.
If this is your world view then the police are at best a necessary evil and may be worse than the criminals. In such a world, the idea that the police exist to hold people accountable for their actions is simply a logical fallacy. In such a world every lawful shooting by police is a bad thing and no positive social good can come from it.
If you want to have fun Google the term "pro-social violence." You know what, it doesn't exist in the storied halls of academia. (Hell, I can probably claim to be it's inventor) The idea that a dangerous criminal being shot is a pro-social act is inconceivable. But guess what, the only way the bad men are kept in check is to face consequences. And please, I'm not talking about extra-judicial violence, but the idea that if you point a gun at the police, you need to be shot, and when it happens, we don't cry for you.
Until we believe that people are responsible for their actions and decisions and getting shot by the police is the natural consequence of poor life choices and "I wouldn't do that shit if I were you" then no left wing hell hole will ever have a police department capable of solving the problems that need to be solved.
There really is something to Orwell's idea of "rough men who stand ready to violence."