For the first time, Mexican victims of crimes tied to the botched Operation Fast and Furious are being identified, including teenagers killed in a 2010 massacre.

A new report finds dozens of weapons recovered in Mexico have been connected with the ill-fated and ill-conceived anti-gunrunning program. While some Mexican authorities estimate 300 of their citizens have been injured or killed by Fast and Furious guns, little has been known about those weapons south of the U.S. border until now.

Through the Mexican Freedom of Information Act, Spanish-language network Univision and Fox News obtained a list of 100,000 weapons recovered in Mexico in 2009 and 2010. The guns were then compared with the serial numbers of the 2,000 guns sold in Fast and Furious.

Univision identified a total of 57 more previously unreported firearms that were bought by straw purchasers monitored by ATF during Operation Fast and Furious, and then recovered in Mexico in sites related to murders, kidnappings and other actions by Mexican hit men and drug cartels.

In an investigative special that aired Sunday, Univision revealed one such massacre that was later found to be linked with Fast and Furious.

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It happened in January 2010 in Juarez, Mexico, where cartel members burst into a home killing 16 people -- mostly teenagers -- at a birthday party. While the gunmen were targeting members of a rival gang attending that party, some of the victims were innocent bystanders.

Family members of those killed have appeared before the Mexican government demanding to know what happened.

"They are waiting for an answer," said Gerardo Reyes, head of Univision's investigative unit. "They want to know what happened. And why they didn't stop these guns from leaving the U.S. and ending up in these crimes?"

"They feel helpless," added Reyes. "They don't know what to do. We interviewed one of them and they said ... 'Who's going to pay for this?'"

It might end up being the U.S. government, should the family of Brian Terry prevail in its wrongful death claim. Terry is the U.S. Border Patrol agent killed in December 2010 in the Arizona desert, and whose murder scene contained weapons linked to Fast and Furious.

"The people can go and sue in the United States with support of American lawyers and that will be a very interesting development certainly," said former Mexican prosecutor Samuel Gonzalez.

The report also reveals the botched operation may have played a role in a 2009 massacre, where 18 young men were killed at a rehabilitation center also in Juarez. The massacre was reportedly ordered and carried out by Mexican hit men.

According to a Mexican Army document obtained by Univision, three of the high-caliber weapons used in the attack were linked to a gun-tracing operation run by the ATF. The partial transcript obtained by Fox News did not specify whether this was Operation Fast and Furious.

The Fast and Furious program caught the attention of Congress and the rest of the country after weapons from the operation were found at Terry's murder scene.

One Justice Department official resigned and another retired after an inspector general report on the probe faulted multiple agencies for letting it get out of hand. Fourteen officials were forwarded for possible disciplinary action.

Republican presidential running mate Paul Ryan has also joined Republicans -- including Mitt Romney -- calling for Attorney General Eric Holder's resignation, with a spokesman telling The Daily Caller Holder should step down or President Obama should ask him to do so.

Fox News' William LaJeunesse contributed to this report.