The Fact Checker obviously takes no position on proposed gun-control laws. But given the attention of recent mass public shootings, is Rubio correct that none of the major shootings in recent years would have been prevented by new gun laws?

Rubio was not specific in his time frame — and a spokesman declined to elaborate — but for the purposes of this fact check we will go back as far as the Newtown shooting in 2012, which touched off the current gun debate.

The Facts

First of all, we should note that there is an unbridgeable gap in opinion about efficacy of various gun proposals, particularly regarding assault weapons and high-capacity magazines.

“The common thread that binds most mass shootings is semiautomatic firearms with the ability to accept a high-capacity detachable ammunition magazine,” said Avery Palmer, communications director at the Violence Policy Center, which supports restrictions on guns. “These can range from assault rifles, pistols, and shotguns, to compact, high-capacity pistols marketed for concealed carry. Today’s gun industry has embraced increased lethality as its marketing lodestar, and one key element in reducing the occurrence and severity of mass shootings lies in ratcheting down the firepower in civilian hands.”

By contrast, gun-rights supporters argue that bans on certain weapons and large-capacity magazines would accomplish little. There are already more than 5 million AR-type rifles in circulation in the United States, ownership of which would have been grandfathered under proposed bans.

A previous nationwide assault-weapons ban, which lasted 10 years and lapsed in 2004, was easily circumvented by gun manufacturers, in part because of various loopholes. The evidence is mixed on how effective that ban was, with both sides often cherry-picking from the most comprehensive report on that law, written in 2004 by Christopher Koper of George Mason University. “The ban did not appear to affect gun crime during the time it was in effect, but some evidence suggests it may have modestly reduced gunshot victimizations had it remained in place for a longer period,” Koper wrote in 2013.

John R. Lott Jr., at the pro-gun Crime Prevention Research Center, notes that such bans would target .223-caliber weapons but would not affect more powerful semiautomatic rifles using .30-06 caliber, which are used for hunting deer. (This video demonstrates the difference.)

Meanwhile, an experienced shooter, as shown in this video, can change a magazine in just two to four seconds. That calls into question whether such a ban would significantly reduce the death toll.

A new study by Gary Kleck of Florida State University studied news accounts of 23 shootings between 1994 and 2013 in which more than six people were killed or wounded and large-capacity magazines were used. In only one case was a shooter stopped as he tried to reload. In all of these 23 incidents, the shooter possessed either multiple guns or multiple magazines, indicating that a determined shooter would not have been deterred by smaller magazines.

Now let’s look at the facts behind Rubio’s statement. Is there evidence that gun law proposals would have prevented the recent high-profile mass shootings?

We developed the following list of 12 mass shootings since 2012 catalogued in the Mother Jones database of U.S. mass shootings, with details obtained from various news and official reports. We will look at whether proposals might have made a difference in how the guns were obtained, or whether existing laws worked as intended.

Mass Shootings since 2012

Dec. 2, 2015: Syed Farook and Tashfeen Malik killed 14 people in San Bernardino, Calif., using a Smith & Wesson M&P AR-15 type rifle, a DPMS Panther Arms AR-15 type rifle, a Smith & Wesson semiautomatic pistol and a Llama semiautomatic pistol. The guns were purchased legally and the rifles were purchased legally by a former neighbor. (The transfer of the rifles to the suspects may have violated California and federal laws.) Four high-capacity magazines were found, perhaps holding as many as 30 rounds.

Analysis: California has some of the strictest gun laws in the nation, dating from 1989, and specific types of AR-15 and AK-47 style rifles are banned. Ammunition magazines that hold more than 10 bullets are also outlawed, though older, larger magazines are grandfathered. A proposal to pass a federal version of California’s law was defeated in the Senate in 2013. There are California has some of the strictest gun laws in the nation, dating from 1989, and specific types of AR-15 and AK-47 style rifles are banned. Ammunition magazines that hold more than 10 bullets are also outlawed, though older, larger magazines are grandfathered. A proposal to pass a federal version of California’s law was defeated in the Senate in 2013. There are indications that the suspects illegally modified their California-compliant weapons. In any case, the laws did not thwart them. (Gov. Jerry Brown, a Democrat, in 2013 vetoed a bill that would have toughened the law, but the guns used in the attack were purchased before the law would have taken effect.)

Oct. 1, 2015: Christopher Harper-Mercer killed nine people at Umpqua Community College in Oregon. He owned 14 firearms and conducted the attack with six of them, including a Glock pistol, a Smith & Wesson pistol, a Taurus pistol and a Del-Ton AR-15 rifle. All were purchased legally.

Analysis: No proposed laws would have prevented these purchases.

July 16, 2015: Muhammad Youssef Abdulazeez killed five people and wounded two at the Navy Operational Support Center and Marine Corps Reserve Center in Chattanooga, Tenn. He used an AK-47-style rifle and 9mm handgun, and a shotgun was in his car. He had multiple 30-round magazines, news reports said. Officials said the gun was obtained legally; other weapons were obtained through Armslist.com, an online forum through which individuals can buy and sell firearms through private transactions.

Analysis: The Senate bill to extend background checks would have included online sales. But because Abdulazeez purchased his other weapons legally, thus passing a background check, a crackdown on online sales likely would not have made a difference in this case.

June 17, 2015: Dylann Roof killed nine people with a .45-caliber Glock pistol that held 13 rounds at a historic black church in Charleston, S.C. Roof legally purchased his gun from a store, but the FBI said he should have failed the background check because he had been charged with possessing Suboxone without a prescription. However, because of clerical mistakes, the FBI said the examiner did not get hold of the report before the three-day waiting period ended, and so the store went through with the purchase.

Analysis: This appears to be an example of an existing law that apparently failed, though some analysts believe Roof actually would have passed the background check if it had been done correctly. The FBI statement incorrectly referred to a felony drug charge, but it was actually a misdemeanor for possession; he did not admit to being an addict. (In a statement after this fact check was first published, the FBI said Roof would have been denied a gun based on an “inference of current use.”) There are also This appears to be an example of an existing law that apparently failed, though some analysts believe Roof actually would have passed the background check if it had been done correctly. The FBI statement incorrectly referred to a felony drug charge, but it was actually a misdemeanor for possession; he did not admit to being an addict. (In a statement after this fact check was first published, the FBI said Roof would have been denied a gun based on an “inference of current use.”) There are also reports that his parents took the gun away from him at some point, but then he took it back.

Oct. 24, 2014: Jaylen Ray Fryberg, a teenager, killed four students with a high-capacity Beretta pistol at the Marysville-Pilchuck High School cafeteria in Marysville, Wash. The pistol belonged to his father, who was the subject of a permanent protection order. That should have prevented the purchase of the gun, but the order had not been entered in the system and so his father passed the background check. The father was later found guilty of knowingly purchasing six firearms he could not legally possess.

Analysis: This is an example of an existing law that failed.

Feb. 20, 2014: Cherie Lash Rhoades killed four people and wounded two at the Cedarville Rancheria Tribal Office and Community Center in Alturas, Calif. She used a 9mm semiautomatic handgun and stabbed a person with a butcher knife when a second gun apparently jammed. It isn’t clear how the gun was obtained; her trial has not taken place. (Note: Rhoades killed her brother, niece, nephew and another tribal member, so some might say this is a family dispute, not a mass public shooting.)

Analysis: There is no indication new gun laws would have made a difference.

Sept. 16, 2013: Aaron Alexis, who had been treated for mental health issues but never committed, killed 12 people with a Remington shotgun at the Washington Navy Yard. He had tried to buy a handgun at a Virginia store but changed his mind after he was told it would have to be delivered to his home state through another federally licensed dealer. But he was able to purchase a shotgun. He passed state and federal background checks; he had been arrested three times but not convicted.

Analysis: The shooter purchased his weapon legally. There have been various legislative proposals at the federal level to help people with mental health issues and to encourage states to submit mental health data for use in background checks. But there is no indication such proposals would have made a difference in this incident. (Note: some states have The shooter purchased his weapon legally. There have been various legislative proposals at the federal level to help people with mental health issues and to encourage states to submit mental health data for use in background checks. But there is no indication such proposals would have made a difference in this incident. (Note: some states have considered or implemented measures that would bar people from buying guns if they have mental health problems but have not been legally committed.)

July 26, 2013: Pedro Vargas set fire to his apartment in Hialeah, Fla., and killed six people with a Glock 17 9mm semiautomatic handgun. Vargas bought his handgun legally and had a concealed weapons permit. (Note: Most of the deaths took place in an apartment complex, not a public space, so some say this should not be considered a public shooting.)

Analysis: No proposed laws would have prevented these purchases.

June 7, 2013: John Zawahri killed five people in Santa Monica, Calif., using a .223 semiautomatic rifle, similar in type to an AR-15. He also had multiple 30-round magazines — which are illegal in California — and during the rampage had dropped a bag which contained additional loaded magazines, a handgun and the upper receiver for a semiautomatic rifle. He also appeared to have made some weapons that are illegal. Investigators later found a 2011 letter from the Department of Justice informing Zawahri that he was not eligible to purchase a firearm.

Analysis: This is another example of where California’s strong gun laws apparently failed to prevent a tragedy. Zawahri was determined to circumvent the law.

April 21, 2013: Dennis Clark III shot and killed his girlfriend in their apartment in Federal Way, Wash., and then killed three other people using a .40-caliber Taurus semiautomatic pistol and a pistol-grip Mossberg 500 pump shotgun with a four-round saddle. The weapons were obtained legally, and he had a concealed pistol license.

Analysis: No proposed laws would have prevented these purchases.

March 13, 2013: Kurt Myers killed four people and wounded two with a shotgun in neighboring towns in Herkimer County, N.Y. The shotgun apparently was obtained legally.

Analysis: No proposed laws would have prevented these purchases.

Dec. 14, 2012: Adam Lanza killed his mother in their home with a Savage Mark II .22-caliber rifle and then killed 26 people, mostly children, with a Bushmaster XM-15 rifle (with a 30-round magazine) at an elementary school in Newtown, Conn. His weapons, which also included handguns and a 12-gauge semiautomatic shotgun, were found in Lanza’s car outside the school and had been legally obtained by his mother, a gun enthusiast. Lanza, in effect, stole his mother’s firearms.

Analysis: The Bushmaster XM-15 would have been banned under the The Bushmaster XM-15 would have been banned under the proposed assault weapons ban of 2013 which failed in the Senate. But the Savage Mark II would have been exempted, as well as the handguns. After the Newtown incident, Connecticut passed a law to bar the sale of AR-15-type rifles and magazines larger than 10 rounds. Gun-control proposals would not have prevented Lanza’s theft of his mother’s legally obtained firearms.

The Pinocchio Test

This is certainly a depressing chronicle of death and tragedy. But Rubio’s statement stands up to scrutiny — at least for the recent past, as he framed it. Notably, three of the mass shootings took place in California, which already has strong gun laws including a ban on certain weapons and high-capacity magazines.

Gun-control advocates often point to the experience in other countries that have enacted gun laws that heavily restrict gun ownership; as we have shown, quantitative measures of cross-comparative crime statistics, especially where the crime is not consistently defined (i.e., “mass shooting”), usually end up being apples-to-oranges comparisons. It is possible that some gun-control proposals, such as a ban on large-capacity magazines, would reduce the number of dead in a future shooting, though the evidence for that is heavily disputed. But Rubio was speaking in the past, about specific incidents. He earns a rare Geppetto Checkmark.

The Geppetto Checkmark

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