When Omar Mateen entered an Orlando, Florida, nightclub on Sunday to carry out the deadliest mass shooting in U.S. history, he wielded a weapon that has been used in massacres from California to Connecticut: a military-inspired semi-automatic rifle.
Though so-called assault rifles account for a small fraction of the United States’ 30,000 annual gun deaths, they have been used in at least 10 mass shootings since 2011, according to a database compiled by Mother Jones magazine.
The prevalence of these firearms has made them a focal point in the debate over U.S. gun laws as opponents say civilians should not own what they describe as “weapons of war.” Backers say they are simply modern rifles enjoyed by millions of law-abiding Americans.
In December 2012, Adam Lanza used a Bushmaster XM15 to kill 28 children and adults at the Sandy Hook elementary school in Connecticut before taking his own life with a Glock pistol. Tashfeen Malik and Syed Farook used two assault rifles and two pistols to kill 14 people in San Bernardino, California, in December 2015.
James Holmes carried an assault rifle, a shotgun and two pistols when he killed 12 people in a Colorado movie theater in 2012.
Law enforcement officials say Mateen, a 29-year-old U.S. citizen who was the son of Afghan immigrants, carried an AR-15 style assault rifle and a handgun when he killed 50 people and wounded 53 at a gay nightclub in Orlando. He also had an unidentified device, said Orlando Police Chief John Mina.
The AR-15 was developed from the U.S. military’s M-16 rifle, used in the Vietnam War in the 1960s. Unlike the military version, the AR-15 is not fully automatic, meaning users must pull the trigger each time they want to fire a shot. Like the military version, many AR-15s combine light weight with a relatively modest recoil.
Prominent manufacturers include Smith & Wesson (SWHC.O), Sturm Ruger (RGR.N) and Remington Arms Co, which faces a lawsuit from some families of Sandy Hook victims who say the rifle should not be sold to civilians.
“It is the gold standard for killing the enemy in battle, just as it has become the gold standard for mass murder of innocent civilians,” said Josh Koskoff, a lawyer involved in the case. The National Shooting Sports Foundation, which represents gun manufacturers, said it would not comment on the Orlando shooting until more facts are known.