* Maryland and Pennsylvania did require background checks on sales of some high-powered rifles and shotguns; this analysis does not calculate which specific sales were covered by the laws in those states.

** In 2016, Nevada passed a ballot initiative requiring background checks on all gun sales, however, the former Nevada Attorney General argued the law could not be enforced, which meant that, in practice, background checks were not required on unlicensed gun sales in 2018.

*** Vermont’s law went into effect April 11, 2018; this analysis does not calculate which sales were not covered in that state.

Read more about our methodology of this investigation and analysis.