Four Arizona residents have pleaded guilty in a sweeping federal drug trafficking case tied to a transnational criminal organization, according to the U.S. Department of Justice on Wednesday.

Federal prosecutors say the group was part of a Phoenix-based operation moving fentanyl, methamphetamine, and cocaine across the U.S., including into western Pennsylvania.

The defendants — ranging in age from 25 to 43 — admitted to drug trafficking and money laundering charges in federal court. Authorities say 26-year-old Marcos Monarrez Jr. co-led the operation with his father, working with a Mexican drug supplier to distribute massive quantities of illegal drugs nationwide.

Investigators say Monarrez Jr. was caught on a federal wiretap coordinating shipments of hundreds of pounds of meth, millions of fentanyl pills, and kilograms of cocaine. He also funneled drug proceeds — over $10,000 at one point — back into Mexico through cash couriers to support the criminal network.

The three other defendants — Jesus Aaron Garcia, Erivan Guerrero, and Donald Garwood — also conspired to traffic large quantities of drugs and move bulk cash through laundering schemes. Guerrero is accused of helping disguise drug money through financial transactions and delivering it to suppliers for transport back to Mexico.

Monarrez Jr. also pleaded guilty to a separate fentanyl conspiracy charge in Michigan dating back to 2019.

Sentencing is set for late 2025. Monarrez Jr. faces mandatory life in prison, while the others face up to life and multimillion-dollar fines.

This case is part of Operation Take Back America, a national effort targeting cartels and transnational drug operations.