U.S. Attorney General Eric Holder testifies during a hearing on the "Oversight of the Justice Department" held by the Senate Judiciary Committee on Capitol Hill
U.S. Attorney General Eric Holder Reuters

Attorney General Eric Holder appeared before a Senate Judiciary Committee hearing, on Tuesday, to discuss Operation: Fast and Furious and Border Patrol Agent Brian Terry. In his statements, Holder said he regretted the incident that led to the death agent Brian Terry.

I regret what happened to Brian Terry, and I can only imagine the pain that his family has to deal with, said Holder. Sen. John Cornyn (R-Texas) has asked the Attorney General whether he wanted to apologize to the family of Terry. But it's not fair to say that the mistakes in Fast and Furious led directly to the death of Brian Terry.

Terry was killed in a firefight last December. The fallout from his death shined light into the covert operation known as Fast and Furious.

Fast and Furious was an attempt by the ATF to track weapons purchased in the US that fell into the hands of Mexican drug lords. The plan was to build a case against the high ranking members in the drug cartels.

However, a major problem occurred. The ATF lost track 1,400 guns, two of which appeared at the scene of Terry's death.

Under questioning, Holder acknowledged the mistakes of Fast and Furious saying it must never happen again. He told the Senate Judiciary Committee that he wants answers from his own department about how the guns ended up in the hands of Mexican drug cartels.

However, Holder also painted a bleak outlook for the future.

Unfortunately, we will feel its effects for years to come as guns that were lost during this operation continue to show up at crime scenes both here and in Mexico, he said.

The program was shutdown last year. Many more missing guns have been linked to hundreds of crimes and dozens of death across Mexico. Fast and Furious weapons were also linked to the death of Jaime Zapata, Immigration and Customs Enforcement agent, who was killed in February outside Mexico City.

Both Terry's and Zapata's families are demanding answers from the Obama administration about the events surrounded the deaths.

The latest hearing was the 17th congressional inquiry related to botched ATF operation. Republican Sen. Charles Grassley and Republican Rep. Darrell Issa said the Justice Department has smeared whistleblowers, misled Congress and denied accountability.

While the story unfolds and allegations continue to arise, Mexico has now threatened to extradite U.S. officials who approved the failed operation. This puts political strain on the two nations.

Mexican President Felipe Calderon criticized the United States saying much of the violence in his country stems from guns bought and sold in the U.S.

In August, the Justice Department replaced three officials who played critical roles in the arms trafficking probe, while the Inspector General, Cynthia Schnedar, is still actively looking into the matter.