I wasn't voicing support for the NYPD, merely noting that as an organization it actually exists far beyond the confines of its city of origin with funding, ties, and "responsibilities" to entities that the Mayor has little to no control over.

Yes, he could theoretically change all of that.

That would also very likely end with cops doing some seriously gang-like shit since, you know, that's what they are.

Politics is messy, especially when dealing with outright evil.