I think it's an important distinction whether crime stops happening after all criminals are locked up or after preventative measures are taken to prevent criminal activity happening in the first place.

When criminals are locked up, they will get released and many of them don't have anything else to do other than returning to do crimes, with gained experience from the previous failures.

But it's possible to reduce crime by preventing it. Do not let dangerous districts form, build communities, reduce access to weapons and so on.