Updated

A federal judge in Arizona barred from the courtroom any testimony touching on why two guns involved in the killing of Border Patrol agent Brian Terry in 2010 were part of the U.S. government-sanctioned program "Fast and Furious."

In a victory for the prosecution, the U.S. government will not have to discuss or explain how federal gun agents allowed rifles to illegally fall into the hands of Mexican drug cartels.

U.S. District Court Judge David Bury said the "Fast and Furious" program was not relevant to the trial at hand and prohibited either side from mentioning the operation “unless the government should open the door by eliciting testimony regarding the history of rip crews and drug trafficking and … a named cartel where the guns wound up.”

The trial for two of the alleged cartel members charged in the shooting, Jesus Leonel Sanchez-Meza and Ivan Soto-Barraza, is set to start in Tucson Tuesday.

Terry was killed in a 2010 gun fight between border patrol agents and members of a of a “rip crew” that robbed drug smugglers wandering in the Arizona desert. Authorities later determined that the gang's weapons were part of the Justice Department's botched "gun-walking" program.

More On This...

The co-defendants were apprehended in Mexico in 2012 and 2013, respectively.

The other members mentioned by the authorities are the brothers Manuel, Heraclio and Rito Osorio-Arellanes; and Jesus Rosario Favela-Astorga. The rip crew's ringleader, Rosario Rafael Burboa-Alvarez, was sentenced to 30 years in prison as part of a plea deal in August.

Manuel Osorio Arellanes was wounded during the fight and arrested near the scene. He pled guilty to first-degree murder and was sentenced to 30 years in prison in 2014. His brother Rito pled guilty to conspiracy to interfere with commerce by robbery and was sentenced to eight years in prison in 2013.

Jesus Rosario Favela-Astorga and Heraclio Osorio-Arellanes remain at large.