They can't. KRS 65.870 prohibits local governments from having any ordinance, rule, etc. banning guns. There's no exception for duplication of federal laws. The feds can have such a law. Now, if the city wants to try to enforce the FGFSZ, that's a different story. Let them try, but they can't have any rule or law of their own, even one that duplicates the federal law word for word. No ordinances means no ordinances and no one has been able to come up with any time the feds wanted to prosecute anyone for a stand alone FGFSZ violation . Any local authority that sees a violation of federal law may hold a violator for pick up by federal officers, should they want to pick them up and try them in a federal court. That is what they do with illegal aliens. That local government still has to obey state law. No "no guns" ordinances (rule, policy etc.) are allowed by city or county governments, period, and I don't think the feds will want to pick up anyone for the stand alone violation. Now, if you do something more than just carry in a school zone, you may get charged with that crime plus an enhancement of a violation of the FGFSZ law, but that prosecution will be by the feds for a federal crime. It won't be by Podunk Junction, Ky. for violation of the FGFSZ law. Local courts don't charge people with federal crimes. Those charges belong in federal court. If you are afraid the FBI or Homeland Security is going to come get you every time you drive past a school with a gun in your car, I'd suggest you leave your gun at home. I don't worry about such foolishness, but that's just me.