Thread by @Klarevas

1/ Last week, @AMJPublicHealth published our new study on whether large-capacity magazine bans are effective in reducing high-fatality mass shootings. Our key finding is that LCM bans appear to save lives.

This thread reports some of the key findings.

ajph.aphapublications.org/doi/10.2105/AJ…

2/ We examined every known high-fatality mass shooting (6+ killed) between 1990-2017. There were 69 incidents in total. We chose 1990 as our starting point because that was when the first LCM ban was enacted by New Jersey.

3/ We were able to determine whether an LCM was involved in high-fatality mass shooting for 60 of the 69 incidents. Of these shootings, 44 involved LCMs – that’s 73%. In other words, most deadly mass shootings tend to involve LCMs.

4/ When LCMs were involved, the average death toll for high-fatality mass shootings increased by 62%. The takeaway is that LCMs appear to be force multipliers.

5/ We also examined how having an LCM ban in place impacted the incidence and fatality rates of high-fatality mass shootings. These rates capture the number of incidents per population as well as the number of deaths resulting from such incidents per population.

6/ We found that jurisdictions that did not have LCM bans in place experienced a 129% increase in the incidence rate and a 206% increase in the fatality rate of high-fatality mass shootings.

These numbers point to an obvious conclusion: LCM bans save lives!

7/ Please feel free to contact me or @lamielltc at @TeachersCollege if you have any inquiries about the study, which was done jointly with @HarvardChanSPH