Via ABC News, an English captioned report by Univision on Fast and Furious.  (video embed not working, click on link to view)

First some background provided by ABC News:

On January 30, 2010, a commando of at least 20 hit men parked themselves outside a birthday party of high school and college students in Villas de Salvarcar, Ciudad Juarez. Near midnight, the assassins, later identified as hired guns for the Mexican cartel La Linea, broke into a one-story house and opened fire on a gathering of nearly 60 teenagers. Outside, lookouts gunned down a screaming neighbor and several students who had managed to escape. Fourteen young men and women were killed, and 12 more were wounded before the hit men finally fled.

Indirectly, the United States government played a role in the massacre by supplying some of the firearms used by the cartel murderers. Three of the high caliber weapons fired that night in Villas de Salvarcar were linked to a gun tracing operation run by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), according to a Mexican army document obtained exclusively by Univision News.

Univision News 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 at least one other massacre.

As part of Operation Fast and Furious, ATF allowed 1,961 guns to “walk” out of the U.S. in an effort to identify the high profile cartel leaders who received them. The agency eventually lost track of the weapons, and they often ended up in the hands of Mexican hit men….

In 2009, the northern Mexican states served as a battlefield for the Sinaloa and Juarez drug trafficking organizations, and as expansion territory for the increasingly powerful Zetas. According to documents obtained by Univision News, from October of that year to the end of 2010, nearly 175 weapons from Operation Fast and Furious inadvertently armed the various warring factions across northern Mexico….

Following the death of Border Patrol agent Brian Terry at the hands of Mexican bandits on December 14, 2010, media and Congressional investigations prompted hearings. On September 20, the U.S. Department of Justice Office of the Inspector General report, which opened the door for sanctions of 14 ATF and DOJ officials.