NEW YORK (AP) — Ismael “El Mayo” Zambada, the powerful longtime leader of Mexico’s Sinaloa drug cartel, is scheduled to be arraigned Friday in New York on a 17-count indictment accusing him of narcotics trafficking and murder.

Sought by American law enforcement for more than two decades, Zambada has been in U.S. custody since July 25, when he landed in a private plane at an airport outside El Paso in the company of another fugitive cartel leader, Joaquín Guzmán López, according to federal authorities.

Zambada later said in a letter that he was forcibly kidnapped in Mexico and brought to the U.S. by Guzmán López, the son of the imprisoned Sinaloa co-founder Joaquín “El Chapo” Guzmán.

U.S. prosecutors in Brooklyn have asked the judge to detain Zambada permanently while he awaits trial. If convicted on all charges, Zambada, 76, faces a minimum sentence of life in prison and would be eligible for the death penalty.

In a letter to the judge, prosecutors called Zambada “one of the world’s most notorious and dangerous drug traffickers.”

“The defendant maintained an arsenal of military-grade weapons to protect his person, his drugs, and his empire,” they wrote. “His heavily armed private security forces were used as his personal bodyguards and as protection for drug shipments throughout Mexico, Colombia, Ecuador, and beyond. Moreover, he maintained a stable of ‘sicarios,’ or hitmen, who carried out gruesome assassinations and kidnappings aimed at maintaining discipline within his organization, protecting against challenges from rivals, and silencing those who would cooperate with law enforcement.”

That included ordering the murder, just months ago, of his own nephew, the prosecutors said.

Zambada pleaded not guilty to the charges at an earlier court appearance in Texas.

His surprise arrest has touched off fighting in Mexico between rival factions in the Sinaloa cartel. Gunfights have killed several people. Schools in businesses in Culiacan, the capital of Sinaloa, have closed amid the fighting. The battles are believed to be between factions loyal to Zambada and those led by other sons of “El Chapo” Guzmán, who was convicted of drug and conspiracy charges and sentenced to life in prison in the U.S. in 2019.

It remains unclear why Guzmán López surrendered to U.S. authorities and brought Zambada with him. Guzmán López is now awaiting trial on a separate drug trafficking indictment in Chicago, where he has pleaded not guilty to drug trafficking and other charges in federal court.