Can gunmaker be held responsible for Newtown shooting?

Can the manufacturer of the assault rifle wielded by Adam Lanza be held responsible for the Sandy Hook Elementary shooting?

The families of nine of the 26 people killed at the school, as well as a wounded teacher, have filed a civil suit that charges just that. According to the plaintiffs, the Bushmaster AR-15 never should have been sold to a civilian because it is a military rifle.

“The AR-15 was specifically engineered for the United States Military to meet the needs of changing warfare,” attorney Josh Koskoff said in a release. “In fact, one of the Army’s specifications for the AR-15 was that it has the capability to penetrate a steel helmet.”

Indeed, the AR-15 was originally developed for military use by ArmaLite Rifles. However, the company later sold the prototype to Colt, which reconfigured the design for civilian use. Today, several manufacturers produce AR-15s, including Bushmaster Firearms International.

At the crux of the lawsuit lies the same question that divides the increasingly embittered gun-control debate: Should it be legal to sell military-style weaponry to civilians?

Gun control advocates have long advocated for a ban on semiautomatic assault weapons. While the 1994 Violent Crime Control and Law Enforcement Act prohibited sale of semiautomatic weapons and large capacity ammunition magazines, the ban expired in 2004. So far, efforts to re-institute the ban have been unsuccessful.

A 2005 law shields gun manufacturers from most lawsuits over criminal use of their products, but it does leave room for cases where the manufacturer knows the weapon is likely to be used in a way that risks injury to others. This lawsuit seeks to capitalize on that loophole.

No one sold Lanza the gun he used to kill his mother, Nancy Lanza, and 26 other people. Before going to the elementary school on Dec. 14, 2012, Lanza obtained the weapon from his mother's home.

The National Rifle Association and gun rights advocates have argued that such weaponry is protected under the Second Amendment as a valuable tool for self-defense and hunting.

“AR 15s are good for hunting,” former National Rifle Association President David Keene wrote in a 2013 blog post on the conservative website HumanEvents.com. “These guns are not the weapon of choice for this nation’s criminals or killers.”

A 2004 analysis of gun-related deaths conducted by the University of Pennsylvania’s Jerry Lee Center of Criminology for the Justice Department found no clear evidence that the decade-long ban made much difference in terms of saving lives.

“Should it be renewed, the ban’s effects on gun violence are likely to be small at best and perhaps too small for reliable measurement,” according to the report. Assault weapons “were rarely used in gun crimes before the ban.”

Family members of the victims of the Sandy Hook shooting say that such statistics offer little consolation.

“My little Daniel’s death was preventable,” Mark Barden, the father of a seven-year-old who was killed during the attack, told reporters during a press conference Monday.

This report includes material from the Associated Press.

[Editor's note: A previous version of this story misidentified the name of the Bushmaster AR-15 on its first use and incorrectly identified the year of the shooting at Sandy Hook Elementary School.]