Michelle Balogh, right, and Kelly Willis speak to reporters Wednesday, Jan. 8, 2020 following the sentencing of the Mexican man…
Michelle Balogh, right, and Kelly Willis speak to reporters Wednesday, Jan. 8, 2020 following the sentencing of the Mexican man who killed their brother, U.S. Border Patrol agent Brian Terry, in December 2010, outside court in Tucson, Ariz.

TUCSON, ARIZONA - A man convicted of shooting a U.S. Border Patrol agent nine years ago in a case that exposed a botched federal gun operation known as ``Fast and Furious'' was sentenced Wednesday to life in prison. 

U.S. District Judge David C. Bury sentenced Heraclio Osorio-Arellanes to the mandatory life sentence after hearing tearful statements from the sisters of Brian Terry, the agent who was fatally shot while on a mission in Arizona on December 14, 2010. 

Osorio-Arellanes is one of seven defendants who were charged in the slaying of Terry. Osorio-Arellanes was convicted of first-degree murder and other charges last year after being extradited from Mexico in 2018. 

Terry's death exposed the ``Fast and Furious`` operation, in which U.S. federal agents allowed criminals to buy firearms with the intention of tracking them to criminal organizations. But the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives lost track of most of the guns, including two found at scene of Terry's death. 

The Obama administration was heavily criticized for the operation. Former Attorney General Eric Holder was held in contempt by Congress for refusing to turn over documents related to the sting. 

Terry, 40, was part of a four-man team in an elite Border Patrol unit staking out the southern Arizona desert on a mission to find ``rip-off`` crew members who rob drug smugglers. They encountered a group and identified themselves as police. 

The men refused to stop, prompting an agent to fire bean bags at them. They responded by firing AK-47-type assault rifles. Terry was struck in the back and died soon afterward. 

Five of the seven men charged in Terry's killing are serving prison sentences after pleading guilty or being convicted. Only one, Jesus Rosario Favela-Astorga, has not been tried. He was arrested in October 2017.