Aurora Gunmans Lethal Arsenal :: 07/23/2012

The three types of weapons used by the man accused of killing 12 people in a Colorado movie theater — a semiautomatic variation of the military’s M-16 rifle, a pump-action 12-gauge shotgun and at least one .40-caliber semiautomatic pistol — are among the most popular guns available in the multibillion-dollar American firearms market.

The weapons have become so common that a growing sport among gun enthusiasts is the “three-gun competition,” in which sharpshooters use a version of each of the weapons as they move from target set to target set, firing and reloading as rapidly as possible.

It appears, the police say, that James E. Holmes, the man accused in the Aurora shootings, used all three types of weapons inside the theater as well, first firing the shotgun, then using the semiautomatic rifle until its 100-round barrel magazine jammed, and finishing off with a pistol. (A second .40-caliber pistol was also found at the scene, though it was unclear whether it had been used in the theater.)

Many other details about the rampage also remain unclear, like whether the gunman used soft-point or full-metal-jacket ammunition, or whether any of the firearms had been modified with scopes or night-vision devices. The police have also yet to disclose how many rounds the gunman fired or which weapon killed or wounded which victims. Fifty-eight people were wounded.

Without such information, much of the public and political attention has been focused on the potential deadliness of the semiautomatic rifle, which law enforcement officials identified as a Smith & Wesson M&P15. The rifle belongs to a class of weapons broadly known as AR-15s, after the original civilian version of the rifle.

With its hereditary links to the M-16, the signature weapon of the Vietnam War and, until recent years, the principal rifle used by American infantry units, weapons like the AR-15 were tightly restricted under a 1994 law known as the assault weapons ban. The law expired in 2004.

The police say the gunman in Aurora used three types of weapons, including a Smith & Wesson M&P15. Nancy Palmieri for The New York Times

But weapons experts said that in a closed, crowded setting like a movie theater, any of the weapons could have been extremely deadly, even in the hands of an inexperienced or inaccurate gunman.

If anything, the experts said, a shotgun in that situation might have been the most lethal, since every shell can spray a half-dozen or more pellets, each capable of killing or maiming a person. Twelve-gauge shotguns often fire five shells, and sometimes more, before needing to be reloaded.

“Shotguns are a very good antipersonnel weapon at close range,” said John C. Cerar, the former commander of the firearms and tactics section for the New York Police Department.

“With that kind of crowd, he didn’t have to be Annie Oakley,” Mr. Cerar said. “He could have closed his eyes and killed a lot of people.”

Mr. Holmes purchased all of his weapons legally, law enforcement officials said. In the four months before the shootings, he also bought 3,000 rounds of handgun ammunition, 3,000 rounds for a semiautomatic rifle and 350 shells for a 12-guage shotgun, all over the Internet.

The original AR-15 was produced by ArmaLite, which sold the design to Colt Manufacturing. Colt marketed a fully automatic version to the military as the M-16, and civilian semiautomatic versions under the trademark AR-15. In recent years, the Pentagon has been replacing the M-16 with smaller M-4 carbines.

Semiautomatic rifles fire just one round with each squeeze of the trigger, while automatic weapons can fire continuously until the trigger is released. Fully automatic weapons are not widely available on the civilian market in the United States.

A Remington 870 pump-action 12-gauge shotgun. Joshua Lott/Getty Images

Smith & Wesson is one of many firearms manufacturers to produce a version of the AR-15, marketing more than a dozen models that range in price from about $700 to $2,000.

The weapon is popular among collectors, military veterans and target shooters who say it is easy to handle and can be modified in numerous ways. Some soldiers call it “a Barbie doll for men” because it has a wide range of accessories and replacement parts, including different styles of barrels, stocks, magazines and scopes.

The M&P15 also comes in a variety of models that fire different sizes of ammunition, from .22-caliber to .30-caliber rounds. The rifle used in Aurora fired .223-caliber ammunition, law enforcement officials said.

Those rounds — similar to the ammunition used in American M-16 and M-4 rifles — are smaller than the rounds fired by Afghan insurgents wielding Kalashnikov rifles, but pack far more power than .22-caliber rounds, even though they are only a hair’s-width larger in circumference.

Law enforcement officials said the 12-gauge shotgun used by Mr. Holmes was a Remington 870. The gun, which can be purchased for around $400, requires the user to pump a handle underneath the barrel to chamber new cartridges after each shot.

The handgun was a Glock .40-caliber semiautomatic pistol, the officials said. The weapon is similar to the 9-millimeter handgun made famous in gangster films and rap music. The 9-millimeter has also been adopted by many police forces that had used .38-caliber revolvers and felt that they were being outgunned by criminals.

The .40-caliber Glock, versions of which sell for about $400, has become increasingly popular partly because its larger round makes it potentially more deadly than a 9-millimeter, Mr. Cerar and other experts said. Yet it has less recoil and is thus easier to handle than a .45-caliber handgun.

The pistols typically come with magazines capable of holding 13 to 17 cartridges.

Pistols are less accurate than rifles at longer distances and are widely considered harder to use because they cannot be braced against the shoulder. But in close quarters, they are plenty lethal.

Correction: July 25, 2012

A picture on Tuesday with an article about the weapons used in the Aurora, Colo., shooting was published in error. It showed a Les Baer .45 — not a Glock .40-caliber semiautomatic pistol, which was used in the shooting. And the article referred incompletely to the availability of fully automatic weapons for sale. While the sale of new machine guns to civilians has been outlawed since 1986, older machine guns were grandfathered into the law and can be sold to civilians in certain states.

http://www.nytimes.com/2012/07/24/us/aurora-gunmans-lethal-arsenal.html?_r=1