PHOENIX (AP) — An appeals court on Friday overturned the conviction and life sentence of a man found guilty of killing a U.S. Border Patrol agent whose death revealed the botched federal gun operation known as “Fast and Furious,” a U.S. appeal that said the court on Friday.

The 9th US Circuit Court of Appeals vacated the convictions of Heraclio Osorio-Arellanes, saying his constitutional due process rights had been violated, and sent the case back to the US District Court in Arizona for further proceedings.

Osorio-Arellanes was convicted in 2020 in the December 14, 2010 shooting death of Agent Brian Terry while on assignment in Arizona.

Osorio-Arellanes was convicted of first-degree murder and other charges after being extradited from Mexico. He was among seven defendants tried and convicted of Terry’s murder.

The appeals court said Osorio-Arellanes had admitted to “substantial parts” of the US government’s case against him when he was questioned in a Mexico City prison.

On appeal, he argued that he was entitled to a new trial because his confession was taken in violation of his Fifth Amendment right against self-incrimination, as well as his Sixth Amendment right to the effective assistance of counsel. He also claimed he did not have a fair trial, and his lawyer said he is illiterate and did not understand the proceedings.

The Obama administration was widely criticized for Operation Fast and Furious, in which US federal agents allowed criminals to purchase firearms with the intention of tracing them to criminal organizations. But the US Bureau of Alcohol, Tobacco, Firearms and Explosives lost track of most of the guns, including two found at the scene of Terry’s death.

Terry, 40 and a former U.S. Marine, was part of a four-man team in an elite Border Patrol unit that took to the southern Arizona desert on a mission to find so-called “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 shoot bean bags at them. Members of the group responded by firing AK-47 assault rifles. Terry was struck in the back and died shortly afterwards.

“Our holding does not determine Osorio’s ultimate responsibility for his actions. The government can still retry this case,” the appeals court said in its new ruling. “Nevertheless, his direct appeal affirms the strength of our Constitution’s procedural protections for criminal defendants, which are “awarded both innocent and guilty.”

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