A Mexican drug lord was released from custody after being convicted in the 1985 killing of Drug Enforcement Administration agent Enrique ‘Kiki’ Camarena. 

Ernesto ‘Don Neto’ Fonseca Carrillo, one of the co-founders of the Guadalajara Cartel, was freed last weekend after completing his 40-year sentence, a federal agent confirmed to the Associated Press. 

Fonseca, 94, had been serving the remainder of his sentence under home confinement outside Mexico City since being moved from prison in 2016. The DEA did not immediately respond to a request for comment Thursday from Fox News Digital. 

Rafael Caro Quintero, another Guadalajara Cartel co-founder who also was convicted in the murder, was one of 29 cartel figures Mexico sent to the United States in February. It’s unclear if the U.S. is now looking to bring Fonseca into custody. 

At the time of his murder, the DEA and Camarena had been utilizing a series of wiretaps to make sizeable drug busts inside Mexico. 

In February 1985, as Camarena left to meet his wife for lunch outside the U.S. consulate in Guadalajara, he was surrounded by officers from the DFS, a Mexican intelligence agency that no longer exists. 

‘Back in the middle 1980s, the DFS, their main role was to protect the drug lords,’ former DEA agent Hector Berrellez, who led the investigation into Camarena’s murder, told Fox News in 2013. 

The DFS agents then took Camarena, blindfolded and held at gunpoint, to one of Caro Quintero’s haciendas nearby. 

For more than 30 hours, Caro-Quintero and others interrogated Camarena and crushed his skull, jaw, nose and cheekbones with a tire iron. They broke his ribs, drilled a hole in his head and tortured him with a cattle prod. As Camarena lay dying, Caro-Quintero ordered a cartel doctor to keep the U.S. agent alive. 

The 37-year-old’s body was found dumped on a nearby ranch about a month later. 

In 2013, Caro Quintero walked free after serving 28 years in prison.  He was released after a court overturned his 40-year sentence for the kidnapping and killing of Camarena. 

Caro Quintero was arrested again by Mexican forces in July 2022 after he allegedly returned to drug trafficking. 

Fox News’ Greg Wehner, William La Jeunesse, Lee Ross and the Associated Press contributed to this report.