Gildardo Lopez Astudillo, alias “El Gil,” is an alleged leader of the Guerreros Unidos cartel, accused of being behind the disappearance and suspected murders of the students from Ayotzinapa teachers’ college in 2014.
Lopez Astudillo had been arrested in September 2015 in the southern city of Taxco, Guerrero state, about 35 kilometers (21 miles) north of the town of Iguala from where the students vanished.
“Gildardo Lopez Astudillo was detained,” a federal security source with knowledge of the case told reporters Friday, asking for his name not to be used because he was not authorized to speak to media.
Lopez Astudillo had been transferred to the Altiplano maximum security prison in Mexico state, the source said.
He was arrested on charges of “organized crime,” although the investigation could be expanded, the source said.
In September 2014, the 43 students had been traveling to a political demonstration in Mexico City when investigators believe they were kidnapped by the drug cartel in collusion with corrupt police.
The exact circumstances of their disappearance are still unknown, but a truth commission set up by the government has branded the case a “state crime,” saying the military shared responsibility, either directly or through negligence.
Arrests have been made or ordered for dozens of suspects, including military personnel and a former attorney general who led a controversial investigation into the mass disappearance.
The remains of only a few of the victims have been identified.
Lopez Astudillo was released in 2019 — a move condemned by family members of the missing students — after a judge found the evidence against him was obtained illegally.
His arrest comes as relatives are preparing demonstrations to mark the anniversary of the students’ disappearance.