EXCLUSIVE: You've heard this shocking "fact" before -- on TV and radio, in newspapers, on the Internet and from the highest politicians in the land: 90 percent of the weapons used to commit crimes in Mexico come from the United States.
-- Secretary of State Hillary Clinton said it to reporters on a flight to Mexico City.
-- CBS newsman Bob Schieffer referred to it while interviewing President Obama.
-- California Sen. Dianne Feinstein said at a Senate hearing: "It is unacceptable to have 90 percent of the guns that are picked up in Mexico and used to shoot judges, police officers and mayors ... come from the United States."
-- William Hoover, assistant director for field operations at the Bureau of Alcohol, Tobacco, Firearms and Explosives, testified in the House of Representatives that "there is more than enough evidence to indicate that over 90 percent of the firearms that have either been recovered in, or interdicted in transport to Mexico, originated from various sources within the United States."
There's just one problem with the 90 percent "statistic" and it's a big one:
It's just not true.
In fact, it's not even close. The fact is, only 17 percent of guns found at Mexican crime scenes have been traced to the U.S.
What's true, an ATF spokeswoman told FOXNews.com, in a clarification of the statistic used by her own agency's assistant director, "is that over 90 percent of the traced firearms originate from the U.S."
But a large percentage of the guns recovered in Mexico do not get sent back to the U.S. for tracing, because it is obvious from their markings that they do not come from the U.S.
"Not every weapon seized in Mexico has a serial number on it that would make it traceable, and the U.S. effort to trace weapons really only extends to weapons that have been in the U.S. market," Matt Allen, special agent of U.S. Immigration and Customs Enforcement (ICE), told FOX News.
Video:Click here to watch more.
A Look at the Numbers
In 2007-2008, according to ATF Special Agent William Newell, Mexico submitted 11,000 guns to the ATF for tracing. Close to 6,000 were successfully traced -- and of those, 90 percent -- 5,114 to be exact, according to testimony in Congress by William Hoover -- were found to have come from the U.S.
But in those same two years, according to the Mexican government, 29,000 guns were recovered at crime scenes.
In other words, 68 percent of the guns that were recovered were never submitted for tracing. And when you weed out the roughly 6,000 guns that could not be traced from the remaining 32 percent, it means 83 percent of the guns found at crime scenes in Mexico could not be traced to the U.S.
So, if not from the U.S., where do they come from? There are a variety of sources:
-- The Black Market. Mexico is a virtual arms bazaar, with fragmentation grenades from South Korea, AK-47s from China, and shoulder-fired rocket launchers from Spain, Israel and former Soviet bloc manufacturers.
-- Russian crime organizations. Interpol says Russian Mafia groups such as Poldolskaya and Moscow-based Solntsevskaya are actively trafficking drugs and arms in Mexico.
- South America. During the late 1990s, the Revolutionary Armed Forces of Colombia (FARC) established a clandestine arms smuggling and drug trafficking partnership with the Tijuana cartel, according to the Federal Research Division report from the Library of Congress.
-- Asia. According to a 2006 Amnesty International Report, China has provided arms to countries in Asia, Africa and Latin America. Chinese assault weapons and Korean explosives have been recovered in Mexico.
-- The Mexican Army. More than 150,000 soldiers deserted in the last six years, according to Mexican Congressman Robert Badillo. Many took their weapons with them, including the standard issue M-16 assault rifle made in Belgium.
-- Guatemala. U.S. intelligence agencies say traffickers move immigrants, stolen cars, guns and drugs, including most of America's cocaine, along the porous Mexican-Guatemalan border. On March 27, La Hora, a Guatemalan newspaper, reported that police seized 500 grenades and a load of AK-47s on the border. Police say the cache was transported by a Mexican drug cartel operating out of Ixcan, a border town.
'These Don't Come From El Paso'
Ed Head, a firearms instructor in Arizona who spent 24 years with the U.S. Border Patrol, recently displayed an array of weapons considered "assault rifles" that are similar to those recovered in Mexico, but are unavailable for sale in the U.S.
"These kinds of guns -- the auto versions of these guns -- they are not coming from El Paso," he said. "They are coming from other sources. They are brought in from Guatemala. They are brought in from places like China. They are being diverted from the military. But you don't get these guns from the U.S."
Some guns, he said, "are legitimately shipped to the government of Mexico, by Colt, for example, in the United States. They are approved by the U.S. government for use by the Mexican military service. The guns end up in Mexico that way -- the fully auto versions -- they are not smuggled in across the river."
Many of the fully automatic weapons that have been seized in Mexico cannot be found in the U.S., but they are not uncommon in the Third World.
The Mexican government said it has seized 2,239 grenades in the last two years -- but those grenades and the rocket-propelled grenades (RPGs) are unavailable in U.S. gun shops. The ones used in an attack on the U.S. Consulate in Monterrey in October and a TV station in January were made in South Korea. Almost 70 similar grenades were seized in February in the bottom of a truck entering Mexico from Guatemala.
"Most of these weapons are being smuggled from Central American countries or by sea, eluding U.S. and Mexican monitors who are focused on the smuggling of semi-automatic and conventional weapons purchased from dealers in the U.S. border states of Texas, New Mexico, Arizona and California," according to a report in the Los Angeles Times.
Boatloads of Weapons
So why would the Mexican drug cartels, which last year grossed between $17 billion and $38 billion, bother buying single-shot rifles, and force thousands of unknown "straw" buyers in the U.S. through a government background check, when they can buy boatloads of fully automatic M-16s and assault rifles from China, Israel or South Africa?
Alberto Islas, a security consultant who advises the Mexican government, says the drug cartels are using the Guatemalan border to move black market weapons. Some are left over from the Central American wars the United States helped fight; others, like the grenades and launchers, are South Korean, Israeli and Spanish. Some were legally supplied to the Mexican government; others were sold by corrupt military officers or officials.
The exaggeration of United States "responsibility" for the lawlessness in Mexico extends even beyond the "90-percent" falsehood -- and some Second Amendment activists believe it's designed to promote more restrictive gun-control laws in the U.S.
In a remarkable claim, Auturo Sarukhan, the Mexican ambassador to the U.S., said Mexico seizes 2,000 guns a day from the United States -- 730,000 a year. That's a far cry from the official statistic from the Mexican attorney general's office, which says Mexico seized 29,000 weapons in all of 2007 and 2008.
Chris Cox, spokesman for the National Rifle Association, blames the media and anti-gun politicians in the U.S. for misrepresenting where Mexican weapons come from.
"Reporter after politician after news anchor just disregards the truth on this," Cox said. "The numbers are intentionally used to weaken the Second Amendment."
"The predominant source of guns in Mexico is Central and South America. You also have Russian, Chinese and Israeli guns. It's estimated that over 100,000 soldiers deserted the army to work for the drug cartels, and that ignores all the police. How many of them took their weapons with them?"
But Tom Diaz, senior policy analyst at the Violence Policy Center, called the "90 percent" issue a red herring and said that it should not detract from the effort to stop gun trafficking into Mexico.
"Let's do what we can with what we know," he said. "We know that one hell of a lot of firearms come from the United States because our gun market is wide open."