The suspect, Heraclio Osorio-Arellanes, is accused of carrying out, with other suspects, the killing of USA border patrol guard Brian Terry in December 2010.
Mexican authorities said Thursday they've arrested one of the fugitives wanted on murder charges in the death of Border Patrol Agent Brian Terry - a shooting that drew new attention to the risky border and exposed a botched Obama administration gun crimes probe.
Two guns found at the scene were eventually traced to a member of a gun-smuggling ring that was being monitored in a Justice Department-sanctioned, gun-tracking operation known as Fast and Furious. The operation set off a political firestorm.
Osorio-Arellanes was arrested by "a joint U.S. -Mexico law enforcement task force that included the Drug Enforcement Administration, U.S. Marshals and the Border Patrol Tactical Unit (BORTAC)", Fox News' William La Jeunesse reported.
Osorio-Arellanes, who is believed to have shot and killed Mr Terry, was detained on Wednesday at a ranch on the border of Mexican states Sinaloa and Chihuahua. The official spoke on condition of anonymity because he was not authorized to comment officially. Their illegal operation was known as a "rip crew", US authorities said. "We are sending a clear message to those who have committed serious crimes and try to enter illegally in the United States that we will vigorously pursue criminal prosecution".
The FBI had offered a $250,000 (£199,100) reward for information that led to the 38-year-old's arrest.
Osorio-Arellanes faces nine charges including first-degree and second-degree murder and assault on a federal officer, among others.
The men refused to stop, prompting an agent to fire non-lethal bean bags toward them.
Terry, 40, was struck by a single bullet and mortally wounded. Another man, Manual Osorio-Arellanes, pleaded guilty to murder and was sentenced to 30 years in prison in 2014. Rosario Rafael Burboa-Alvarez was sentenced to 27 years as part of a plea deal. They ran into five members of a "rip crew" - low-level drug cartel operatives looking for drug smugglers to rob - and attempted to arrest them.
Only Jesus Rosario Favela-Astorga remains at large.