[UPDATE, 4:42 p.m.: The shooter has been identified as 20-year-old Adam Lanza. Initial reports identified the gunman as his brother, 24-year-old Ryan Lanza, who is being questioned but not a suspect.]

Police said they recovered a Sig Sauer rifle and a Glock, used by a suspected gunman, identified as a Ryan Lanza, at a shooting Friday at Sandy Hook Elementary School in Connecticut.

The Sig Sauer is a semi-automatic rifle, while the Glock has been identified as 9mm handgun.

The suspected gunman reportedly was carrying both weapons during the shooting in Connecticut. Police have said that at least 27 people, including children, were killed as a result of the shooting spree.

Lanza, who has been identified as the gunman, was pronounced dead at the scene of the shooting, according to multiple news reports.

NBC News, which picked up an article from the Associated Press, said that of the two guns recovered, one of them was a .223 caliber rifle. Earlier, CNN had identified the two guns as a Sig Sauer and a Glock.

Twitter was quick to identify the potential weapon used in the shooting at the elementary school. The Sig Sauer is a semi-automatic rifle, that is possibly part of the Sig Sauer SIG556 series of semi-automatic rifles. They can be bought retail starting at about $1,266 for a SIG556 Classic, which features a 16” barrel length and a magazine capacity of 30 rounds, according to some reports.

While these semi-automatic rifles use 5.56mm NATO rounds, the bullets are derived from .223 Remington bullets, and the two can be used with the same rifle, although it may not be as accurate, gun experts said.

The SIG556 HOLO comes with several different sighting options and weighs 7.8 pounds. The SIG556 Classic weighs 8.2 pounds.

According to the manufacturer's description, “The SIG 556 Classic brings back the look and feel of one of the world’s most sought after military rifles but on a platform available for law enforcement and responsible citizens.”

According to Nation Master, the SIG556 can fire up to 700 rounds a minute.

A video review from American Rifleman TV of the SIG556 can be viewed below.