To be fair it's never really clear what is cause and what is effect with gun laws in the USA -- places with high crime of certain kinds (urban/black, with liber

To be fair it's never really clear what is cause and what is effect with gun laws in the USA -- places with high crime of certain kinds (urban/black, with liberal or anti-gun politicians) tend to go for anti-gun laws. Places with low crime and lots of anti-gun people also go for anti-gun laws. Places with high crime and a more pro-gun culture resist those laws. It's hard to say passing a law pro or anti gun changes crime; you'd really need something equivalent to a "twin study" in bio, where two otherwise-identical cities at the same time pass different laws.