AR-15-style semi-automatic rifles or similar guns were used in at least six of the 14 mass shootings so far this year in which four or more victims died, says the Gun Violence Archive. In eight shootings, information was unavailable about the types of guns used, USA Today reports. While semi-automatic rifles have become more widely used over the past decade, handguns remain the most common type of gun used in mass shootings. According to The Violence Project, 78 percent of mass shooters since 1966 used at least one handgun. The group keeps its own database and defines mass shootings as events in which four or more victims were killed, not including the shooter.
At least one assault weapon has been used in forty four percent of mass public shootings since the July 2012 movie theater massacre in Aurora, Co. Across the previous five decades, an assault weapon was used in almost twenty one percent of mass shootings, said James Densley of The Violence Project. This year alone, mass shooters used semi-automatic weapons to kill over 40 people between May and July in Buffalo, Uvalde, Tulsa, and Highland Park, Il. “In the past 10 years, mass public shootings involving assault weapons have resulted in average death tolls that are more than double the average death tolls for mass public shootings that did not involve (them),” said Prof. Louis Klarevas of Columbia University’s Teachers College.