Following the airport shooting, Steube doubled down on his view that license holders ought to bring guns into venues like airports, claiming that gun-free zones are more likely to be targeted by shooters. In fact, most major airports are not gun-free zones, as they have armed and unarmed security personnel. In addition, several studies show the vast majority of mass shootings do not occur in gun-free zones. In his book, "Rampage Nation," Louis Klarevas of the University of Massachusetts found that 93 of 111 mass shootings from 1966 to 2015 occurred in zones in which guns were not prohibited.