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But counter to what gun-rights advocates claim, many of the active shootings in the FBI’s database occurred in areas that were not gun-free zones. Our own analysis of the FBI study, in which we looked at all 160 incidents, examining state and local laws along with the firearms policies of individual businesses, found that of the 65 shootings in open spaces and businesses with pedestrian traffic, at least 25 occurred in areas permitting firearms.

That may amount to less than 50 percent — but we counted only those cases in which the evidence indicating that the open space or business was not a gun-free zone is unmistakably clear. Complicating this analysis are differences in state laws governing whether “no-firearms allowed” policies in businesses are actually enforceable, and the fact that many concealed carriers aren’t aware of (or deliberately ignore) no-firearms policies.