According to testimony provided to investigators with the House Committee on Oversight and Government Reform, the two guns were sold to a straw buyer watched by agents of the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, who were under orders not to stop the guns from crossing the border. The ATF surveillance program, called Operation Fast and Furious, was supposed to lead to the arrests of high-level drug cartel figures.
Gonzalez, kidnapped in October, became well-known across Mexico with the release of a video showing him handcuffed and surrounded by hooded gunmen, making a statement — under obvious duress — that alleged that his sister had been involved ordering killings and in protecting the Juarez drug cartel.
His body was found in November. Patricia Gonzalez Rodriguez, who has denied the charges, asserted that her brother had been kidnapped by members of the Sinaloa cartel.
Several municipal police officers arrested in connection with the killing were subsequently released.
"Following Rodriguez's murder, when Mexican police attempted to arrest the suspects, guns with serial numbers tracing back to Operation Fast and Furious were found at [the] scene," a brief oversight committee statement said.
Another source familiar with the investigation said ATF agents learned that the guns were Fast and Furious weapons when their serial numbers were found in a database of information on guns sold to suspect straw buyers being watched under Fast and Furious.
The Mexican government has been notified of the match, the source said. On Friday, oversight committee Chairman Darrell Issa (R-Vista), who has been leading the investigation of the ATF operation with Sen. Charles E. Grassley (R-Iowa), will travel with a bipartisan delegation to Mexico, partly in an attempt to draw the government there further into the investigation.
In a letter this week to Mexico's U.S. ambassador, Arturo Sarukhan, Issa and Grassley requested serial numbers of all firearms recovered in "substantial" violent crimes, along with the numbers of any other weapons that government officials have reason to believe may be connected to the operation.
"This information would be tremendously helpful to us in determining the full scale of the effects of Operation Fast and Furious, which includes the deaths of both Mexican and American citizens," the two lawmakers wrote. "We have a shared interest with you in getting to the bottom of this matter."
Issa will be joined by eight other U.S. lawmakers for meetings Saturday in Mexico City at the federal police command center and also with representatives of the U.S. Embassy.
Mexican officials have not commented on the latest revelations about the two AK-47s linked to the Gonzalez case.
"What I can tell you is there are investigations underway, and as a matter of policy, we don't comment on ongoing investigations. We will wait and see what comes out of those investigations," said Ricardo Alday Gonzalez, spokesman for the Mexican Embassy in Washington.