And that's the problem - prosecutors don't want to do anything that makes police officers unhappy. That means requiring the police to obey the law. It means supporting the police when they murder people.

It's somehow considered acceptable - as in not a fireable offense - for police officers to not do their job or to prevent the prosecutors from enforcing the law.

Because police as currently operating in large portions of the US are not meaningfully different from gangs. Only they are even less likely to suffer consequences.