>>js2+(OP)
"Police" (Edit:"modern police") is a 19th century invention, well after cities were a thing. If we get past semantics, a service that provides order and security to a community is needed. I imagine it more like social workers that also do criminal investigations for prosecutors instead of a military force for a city. Perhaps an unrelated armed "police" can help when deadly force is needed (gangs, armed criminals,etc...).
Disarm and civilize the police but keep their SWAT units as a separate department that only backs up police when requested.
This would throwing a lot less people in jail and having police that live in the community. But hey, this is just wishful imagination, politicians and police union would commit sedition if anything like this happened.