Update: In the immediate aftermath of Sunday's deadly shooting, police identified the long gun Omar Mateen used as a AR-15-style rifle. The exact model was later revealed to be a Sig Sauer MCX, which is technically different from an AR-15. Tactical Life has a good rundown of the differences between the two.
Over three hours early Sunday morning, Omar Mateen, barricaded inside a gay nightclub in a residential neighborhood of Orlando, shot and killed 49 people; an additional 53 were wounded. The standoff ended around 5 a.m., when Mateen was killed by police.
Mateen carried two guns with him Sunday: a 9mm handgun and a .223 caliber AR-15-style semi-automatic rifle. Both guns were purchased legally within the last week in Florida, authorities confirmed Sunday.
Mateen, a security guard, was licensed to carry a concealed weapon. In Florida, though, you don't need a license to buy or carry a rifle like the AR-15. There is a three-day waiting period to purchase a handgun like the Glock Mateen also had on him, but no waiting period at all to buy an AR-15.
According to Mother Jones, the a model known as the "Black Mamba," and it "has a military-spec trigger and a magazine capacity of 30 rounds."
The AR-15 is one of the most popular, and most easily obtained, guns in America. In 2013, the National Shooting Sports Foundation estimated there are somewhere between 5 million and 8.2 million assault weapons in circulation.
That number has undoubtedly increased in the intervening years, as sales of the gun spike after each mass shooting. But precise numbers are anyone's guess, because the federal government does not track sales or require purchasers to register long guns.
Experts attribute the AR-15's popularity to its image, its ease of use, its nominal recoil and the rate at which it fires. It's semi-automatic, meaning it can release bullets as fast as the shooter pulls its trigger, and can continue firing until the magazine is empty.
Nicole Hockley, who lost her child in the 2012 Sandy Hook shooting, explained the gun's appeal another way: The man who killed her son, she said earlier this year, "chose the AR-15 because he was aware of how many shots it could get out, how lethal it was, the way it was designed, that it would serve his objective of killing as many people as possible in the shortest time possible."
In addition to Sandy Hook (26 dead; 2 wounded), the AR-15 was used in recent massacres at a movie theater in Aurora, Colorado, in 2012 (12 dead; 70 wounded), a community college in Roseburg, Oregon, in 2015 (10 dead; 9 wounded), and an office holiday party in San Bernardino, California, also in 2015 (14 dead; 22 wounded).
The standard magazine for a Glock, like the one Mateen carried, is 15 rounds. The Sig Sauer MCX rifle Mateen used had double that capacity: 30 rounds. A Snapchat video taken at the scene in Orlando illustrates its devastating power: the shooter can be heard firing more than 20 shots in a single nine-second stretch.
AR-15-style rifles can be modified, as the gun used in the Aurora shooting was, to use a magazine that holds as many as 100 bullets.
AR stands for "ArmaLite rifle," after the company the developed the gun for use by the U.S. military in the 1950s. (The military's version, nearly indistinguishable from the AR-15, is called the M-16.) Today Colt holds the AR-15 trademark, but some 282 manufacturers make their own versions of the gun and its parts, according to a 2014 accounting by AR-15 enthusiasts.
One of those is Remington, manufacturer of the Bushmaster AR-15, which was used in the Sandy Hook shooting. Remington's parent company, Freedom Group, is presently being sued by the families of the victims of that shooting.
In a statement Sunday, lawyers for the families reiterated the crux of the argument they plan to use against the gunmaker in court: that the AR-15 is a military-style weapon, and that it should have never been sold to civilians.
The AR-15 "was designed for the United States military to do to enemies of war exactly what it did this morning: kill mass numbers of people with maximum efficiency and ease. That is why the AR-15 has remained the weapon of choice for the United States military for over 50 years," lawyer Josh Koskoff said in a statement. "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."
Semi-automatic weapons like the AR-15 were, at one time, banned nationwide. The 1994 federal assault weapons ban prohibited most versions of the rifle from being sold in the U.S. The gun re-entered circulation after Congress allowed the ban to expire in 2004. Subsequent efforts to renew the ban, or create other legislation that would limit assault weapons, have been unsuccessful.
Last summer, Wal-Mart — the biggest gun seller in America — announced it would stop selling AR-15s, but as of Monday morning, AR-15 parts and kits were still available on the retailer's website.
Update and correction: This piece has been updated to reflect the name of the AR-15 model used in the shooting, and corrected to reflect fact that the Snapchat footage from the scene of the crime captured more than 20 shots fired in a single nine-second stretch, not a 90-second stretch.
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