Batman is copaganda.
Police sanctioned vigilantism.
Note that the cops almost never really wanted to arrest him even when they felt they had to because it was their job and he was a public relations nightmare. That was always the problem, public relations.
How much of their public relations nightmare was that a private citizen was being more effective at wielding the violent force that we expect to be the exclusive property and responsibility of the state, to keep the streets clean and safe?
Bingo.