(NewsNation) — Mexican authorities on Wednesday arrested Néstor Isidro Pérez Salas, one of the lead assassins in the Sinaloa drug cartel, the U.S. Justice Department announced.

Salas, known as “El Nini,” led security operations for the Chapitos and is accused of kidnapping, torturing and killing rivals, witnesses and others who opposed the Chapitos, the Justice Department said in a statement.

Attorney General Merrick Garland said his agency will seek to have Salas extradited to face charges in the U.S.

“The Justice Department is grateful to our Mexican counterparts for their work in that effort, and we remain committed to doing everything in our power to dismantle the dangerous drug trafficking cartels that are responsible for death and devastation in both the United States and Mexico,” Garland said in a statement.

Salas was indicted in 2021 by a federal grand jury on drug trafficking and other charges, according to the State Department, which was offering a $3 million reward for information leading to his arrest. Salas was indicted a second time in April 2023 on drug and money laundering charges, among others.

His arrest follows that of Ovidio Guzman Lopez, the youngest son of notorious drug lord Joaquin “El Chapo” Guzman, who ran the Sinaloa Cartel.

Pérez Salas allegedly protected the sons Joaquín Guzmán, and also helped in their drug business. The sons lead a faction of the cartel known as the little Chapos, or “Chapitos” that has been identified as one of the main exporters of fentanyl, a deadly synthetic opioid, to the U.S. market.

Pérez Salas commanded a security team known as the Ninis, “a particularly violent group of security personnel for the Chapitos,” according to the indictment unsealed in April. The Ninis “received military-style training in multiple areas of combat, including urban warfare, special weapons and tactics, and sniper proficiency.”

The nickname Nini is apparently a reference to a Mexican slang saying “neither nor,” used to describe youths who neither work nor study

The Associated Press contributed to this report.