Are Mass Public Shootings Seasonal? (Corrected)

***CORRECTION: A FACEBOOK READER noticed something in the Mother Jones data I presented recently that I had missed. Beginning in 2013, MJ changed their definition of a mass public shooting from 4 or more victims to 3 or more victims in 2013 (see more below), but did not retroactively update their database. Although not deceptive (they said plainly they were doing this, I simply missed it), this is methodologically problematic. So I eliminated those cases, which reduces the total number in the database from 114 incidents to 95, and re-did the chart here.***

Gun trainer Rob Pincus texted to ask me tonight if I had any source for data on the seasonality of mass shooting activity. I.e., mass shootings by month.

I did not, but I was intrigued enough by the idea to do a little work when I got home tonight. The fruit of that labor is below. Important notes and interpretive points follow the chart.

Why I “Need” an AR-15 by Jon Stokes

The debate over civilian ownership of AR-15 platform rifles heats up every time there is a mass murder in the United States using one. Because I study gun culture, people often ask me, “Why does anyone need one of those weapons of war, anyway?”

I usually don’t have a good answer, since handguns are the gun of choice of Gun Culture 2.0, and most of my personal experience with firearms has been with handguns. In fact, about 5 years ago I bought an AR platform rifle with the intention of learning more about it, and it sat untouched for 4 years. Last fall someone shot 5 rounds through it and it has not been touched again since.

So I am happy to bring forth the writing of someone who has thought about this issue more than I have. Jon Stokes is a computer engineer who has two master’s degrees from Harvard Divinity School, co-founded Ars Technica, was an editor at Wired, and continues to be a progressive gun nut.

I appreciate his allowing me to re-print his essay, “Why I ‘Need’ an AR-15,” originally published on Medium in June 2016 following the mass murder at the Pulse Nightclub in Orlando.

Image courtesy of Oleg Volk