John Lott and Carlisle Moody (2019) have unwittingly replicated a major finding from my study and confirmed its accuracy: the United States has far more than its global share of public mass shooters (Lankford 2016). To understand how they did this without realizing it, you have to know only one thing about this specific type of criminal—which as Lott and Moody acknowledge, is similar to “active shooters” or “rampage shooters” and traditionally defined by having killed four or more victims, along with several other criteria.

They almost always attack alone. This is such common knowledge that I am surprised it requires any comment. Most laypeople already know this without my needing to say so, and certainly all researchers with experience in this area recognize this simple fact. It is one of the things that makes public mass shootings so terrifying: they are one of the most vivid demonstrations of just how much death and destruction a single person can cause on his own