Another day, another massacre — and it’s hard to explain why
The Washington Post - 07/24/2015
A 2014 FBI study of 160 active-shooter events since 2000 showed a staggered increase over time, with the four most violent years occurring in the last five years of the survey. Criminologist James Alan Fox of Northeastern Universityhas questioned the rigor of the FBI calculation, saying it may be influenced by media reports. But if this is a real trend and not a fluke — a spike that will be followed by a drop in such incidents — then it is one not easily explained. This appears to be an emergent phenomenon with no single cause and no simple fix.