1) Mass shootings in "gun-free zones," by definition, are not likely to be stopped by a civilian with a firearm as civilians (i.e. victims) are disarmed by law. 2) The FBI states that there were 50 "active shooter incidents" in two years. Contrast that to the outrageously high numbers of "school shootings" and "mass shootings" routinely given by anti-gun groups based on arbitrary definitions created by a blogger and others to skew the numbers in favor of their argument to repeal the 2A. Of note, seven (7) "active shooter incidents" occurred in "education environments" in two years. Contrast that with the number of "school shootings" claimed by anti-gun groups over those two years. It would be interesting to see how these data compare to the mass murder/mass killing numbers using the original definition (4 or more people killed, not counting the shooter) vs. the lowered threshold of the Obama 2013 definition (3 or more people killed, counting the shooter). Key points from the the publication: It sounds as though even if not one person was shot, it could still count as an "active shooter incident." These are often included in anti-gun statistics. Kudos to the FBI for excluding them. Guns were banned at the latter two, and guns would have been useless at the former, regardless of whether they were banned from a large concert venue. The casualty numbers from Vegas also presume to be all from gunshot wounds and do not specify trampling, etc. The latter event (Sutherland Springs) was effectively stopped by an armed civilian neighbor. That's an 80% success rate for people trying to stop these scum bags. Virtually everyone would rather have a gun in trying to stop them rather than being unarmed.