"AR-15-style rifles have become something of a weapon of choice for mass shooters. One was used last year to kill 26 people during Sunday morning church services in Sutherland Springs, Texas, and it was among the stockpile of firearms used a month earlier to kill 58 concertgoers in Las Vegas. AR-15-style rifles were also used at the shootings at Pulse nightclub in Orlando, Florida; at an employee training in San Bernardino, California, and at Sandy Hook Elementary School in Newtown, Connecticut."