He may want to check out federal law first.
They can't do it if they receive ANY federal funding. A law was passed after Katrina that makes it illegal for municipalities to suspend a citizen's Second Amendment rights just because of an emergency.
Citation please, if you know of it...I can't seem to catch it with the almighty google. I had heard this before, but I'd like to cite chapter and verse if possible. Warmish debate with RINO coworker, and this sort of thing came up.