Is Las Vegas the worst mass shooting in US history? It’s surprisingly complicated
Vox - 10/02/2017
For example, the Gun Violence Archive and Vox count any event in which four or more people were shot, but not necessarily killed, at the same general time and location. Some criminologists, such as Northeastern University professor James Alan Fox, prefer to include any shooting in which four more people are killed. Mother Jones editor Mark Follman, who has done a lot of reporting on mass shootings, prefers a very narrow definition that includes shootings in which four or more people are killed and excludes all domestic, gang, and drug violence. And there are even more ways to interpret the definition of a mass shooting.