Fig. 2

Number of ERPO-related articles published in U.S. newspapers per week, 2018. Each tick mark on the x-axis represents a week, starting with the week of January 4, 2018. Public mass shooting events are noted in boldface. The definition of mass shooting for events noted here is a single attack in a public place in which three or more victims are killed. Public mass shooting events come from Follman et al., 2020 [28] and are available in Additional file 1, Table S3. ERPO policy introductions and passages are noted in non-boldface. Legislative dates were ascertained from state legislature websites and from Campbell et al., 2020 [29] and are available in Additional file 1, Table S4. To view raw data (weekly counts of ERPO-related articles for 2018), see Additional file 1, Table S5