Updated

Mexican federal police announced Friday that they have arrested a suspect in the killing of U.S. Border Patrol agent Brian Terry, the slaying at the center of the scandal over the botched U.S. gun-smuggling probe known as Operation Fast and Furious.

Jesus Leonel Sanchez Meza is one of the five men charged with killing Terry in December 2010 during a shootout in Arizona near the Mexico border. One is on trial in Arizona and the other three remain fugitives. Sanchez was arrested Thursday in Sonora state.

Two guns found at the scene were bought by a member of a gun-smuggling ring that was being monitored in the Fast and Furious investigation. Critics have knocked U.S. federal authorities for allowing informants to walk away from Phoenix-area gun shops with weapons, rather than immediately arresting suspects.

In Operation Fast and Furious and at least three earlier probes during the administration of President George W. Bush, agents in Arizona employed a risky tactic called gun-walking -- allowing low-level "straw" buyers in gun-trafficking networks to leave with loads of weapons purchased at gun shops. The goal was to track the guns to major weapons traffickers and drug cartels in order to bring cases against kingpins who had long eluded prosecution under the prevailing strategy of arresting low-level purchasers of guns who were suspected of buying them for others.

During Operation Fast and Furious, many of the weapons weren't tracked and wound up at crime scenes in Mexico and the U.S., including the Terry shooting.

In July, U.S. authorities made a rare disclosure linked to the botched gun-smuggling probe, revealing identities and requesting the public's help in capturing the four fugitives accused in the shooting death of Terry.

The release of the suspects' identities in an unsealed indictment came with the offer of a $1 million reward for information leading to their capture.

The FBI said it was seeking information related to Jesus Rosario Favela-Astorga, 31, Ivan Soto-Barraza, 34, Heraclio Osorio-Arellanes, 34, and a man identified as Lionel Portillo-Meza, which Mexican police said was an alias of the man arrested Thursday in Puerto Penasco, Sonora.

Portillo-Meza's age and birthplace were unavailable. The other three fugitives were born in Mexico, but their hometowns were not available.

Authorities had previously released the identity of the fifth suspect, Manuel Osorio-Arellanes of El Fuerte in the Mexican state of Sinaloa. He was shot during the gunfight and has been in custody since the night of the shooting. He has pleaded not guilty in the case, telling investigators that he raised his weapon toward the agents during the shootout but didn't fire, the FBI said in records. His age was not immediately available.

All five men have been charged with murder. They also face charges of assaulting four federal agents.

FBI agents declined to discuss which fugitive is suspected of firing the shot that killed Terry. They also would not comment on whether the weapon was linked to an Operation Fast and Furious purchase.

The five men, plus another who faces lesser charges in the case, went to the U.S. from Mexico in order to rob marijuana smugglers, the indictment said.