Fox News' Sean Hannity falsely claimed that a background check occurs on every gun sale in America to attack an ad that calls for action on gun violence in memory of the December 2012 mass shooting at Sandy Hook Elementary School in Newtown, Connecticut.

The December 10 edition of Hannity included a segment on a new ad called “No More Silence” from gun violence prevention groups Moms Demand Action for Gun Sense in America and Mayors Against Illegal Guns (MAIG). The ad depicts a moment of silence for victims of the Newtown tragedy while also advocating for action to be taken on gun violence to prevent future tragedies. Asking if the ad was “politicizing tragedy,” Hannity made a number of false claims about gun violence during the segment:

After American Values Institute Executive Director Alexis McGill Johnson said that action on gun violence would include reforms so that “every gun sold has a background check,” Hannity replied, “We already have that.” (Both MAIG and Moms Demand Action make expanding checks a major component of their advocacy.)

In fact, a significant number of firearms are sold without background checks through so-called private sales, often at gun shows or over the Internet. Gun shows and websites that specialize in private sales have been linked to illegal trafficking operations, both narcoterrorismand international terrorism, and serve as conduits for individuals who would fail a background check because they are prohibited by law from owning a gun. Indeed, research has shown that a large percentage of criminals obtain firearms through private transactions.

What makes Hannity's claim about background checks even more surprising is that a bill to expand checks to all commercial gun sales was the centerpiece of legislation debated in the United States Senate after Newtown. While exempting firearms transfers between family members and friends from the check requirement, the legislation would have essentially required individuals selling guns to strangers for profit to have the purchaser undergo a background check. Despite receiving a majority vote, the bill was blocked largely by Republican Senators, although gun violence prevention advocates hope the legislation will receive another vote in the future.

Hannity also touted the National Rifle Association's canard that armed guards at schools are a panacea to school shootings, in one instance claiming, “If every criminal knew that every school had armed guards, I think a message is sent that, you know what, we are not going to take this anymore. We're not going to have sitting ducks, these gun-free zones that prevent people from even thinking of defending themselves.”

A signification portion of schools already have armed guards but research suggests it is unclear whether guards in schools actually stop school shootings. An armed guard exchanged fire with the shooters during the 1999 Columbine High School massacre but was pinned down by the shooters' superior firepower, and the 2007 Virginia Tech massacre occurred at a school that had an emergency response team described as “like a SWAT team.”

Despite Hannity's suggestion, places where guns are not allowed do not invite mass shootings. For example, schools -- where guns are typically prohibited -- are actually typically safer for young people than the surrounding community, despite tragedies like Newtown. Hannity's fixation on armed guards also discounts that it makes more sense to find solutions to prevent gun violence prior to the moment when a gunman shows up at a school.

Hannity also misled on high-capacity magazines -- sometimes imprecisely called “clips” -- like the 30-round magazines used in the Newtown shooting by suggesting that because he could “drop a clip and put another clip in my gun” in “seconds,” there was no point to restricting magazine size as a reaction to Newtown.

Two recent mass shootings demonstrate how seconds can mean the difference between life and death when a shooter uses a high-capacity magazine. During the January 2011 mass shooting in Tucson, Arizona, that killed six and gravely wounded then-Rep. Gabrielle Giffords among others, the shooter was only stopped when he was tackled as he paused to reload after firing 31 bullets in 16 seconds from a high-capacity magazine. Parents of some of the children killed at Sandy Hook Elementary School were told by authorities that a number of children were able to escape the shooter when he paused to reload. At a press conference in support of a Connecticut proposal to ban high-capacity magazines in that state, Mark Barden, whose son was killed in the mass shooting, explained, “The more times you have to reload the more opportunities there are to escape and to stop the shooting. In the amount of time -- it was somewhere around four minutes -- he was able to fire 154 rounds. I think that speaks volumes about reducing the size [of magazines].”

Hannity previously attacked calls for action on gun violence following the Newtown shooting by characterizing some parents of children who died in the attack as “props” for Obama's gun policy agenda.