The Atlantic: “Several years ago, Malcolm Gladwell wrote an article in The New Yorker positing that national school shootings might spread like a disease. He cited the models of the Stanford University sociologist Mark Granovetter, whose theory of social-influence “thresholds” explained the gathering force of a riot. Imagine an avalanche, where the first tranche of snowpack to move might be quite unsteady, but as the wave of snow gathers force, it becomes powerful enough to dislocate even the most stable trees and houses. Similarly, a riot might begin with one wild rebel throwing a rock through a window just to get a rush. It becomes a public movement when the momentum is powerful enough to move even the relatively stable people nearby to join in the rock-hurling. But according to a 2015 paper out of Arizona State University, “Contagion in Mass Killings and School Shootings,” there is some data that mass shootings often occur in bunches, suggesting that they “infect” new potential murderers, not unlike a disease. “We find significant evidence that mass killings involving firearms are incented by similar events in the immediate past,” the authors wrote. Suicide and terrorism, too, have been found to be similarly contagious. (Interestingly, the authors found “no significant association” between the rate of school and mass shootings and the state’s prevalence of mental illness.) Diseases spread between individuals, but the contagion of mass shootings seems to spread through broadcast media.” [h/t/ Pete Weiss]

See also extensive reporting on the “latest” mass shooting in Texas: Church Shooter Unloaded 15 Gun Magazines, Was Found Dead With Three Gunshot Wounds. A gunman entered a church in Sutherland Springs, east of San Antonio, Texas, and opened fire Sunday. He was later found dead in his vehicle after a short pursuit.

And once again, see Mother Jones – US Mass Shootings, 1982-2017: Data From Mother Jones’ Investigation – The full data set from our in-depth investigation into mass shootings.

Axios – “…three of the five deadliest mass shootings in modern U.S. history have happened in the past 17 months. The others: Orlando in June 2016, and Vegas just last month.”