ORLANDO, FLORIDA — On June 12, Omar Mateen committed the worst single-day mass shooting in U.S. history, using the same type of gun that has killed countless innocents in similar tragedies.
According to the National Rifle Association, the AR-15 is America’s most popular rifle, with at least 9 million in circulation as of 2014, reports USA Today.
The AR-15 was created by ArmaLite in 1957 for the U.S. Army, which needed a lightweight, high-velocity rifle. The original prototype didn’t pass standards, but a redesigned version was adopted by the military in the 1960s and renamed the M16. The AR-15 we know today is its civilian equivalent.
The fully automatic M16 can fire 30 rounds in two seconds with one pull of the trigger. The AR-15 and similar style rifles are 22-caliber semi-automatic weapons that require the trigger to be pulled and released for every shot fired.
The rifle has been used in at least five mass shooting incidents since 2012. Most recently, Mateen used it to open fire at a gay nightclub in Orlando.
In states like Florida, no gun license is required to buy a gun. The Florida state legislature mandates a three-day waiting period for small guns between purchase and delivery, but not for rifles and similar guns.