Who is ‘el Mencho’ and the Jalisco New Generation Cartel?
CNN’s Valeria León breaks down how Nemesio “El Mencho” Oseguera Cervantes became Mexico’s most-wanted cartel boss and the head of the Jalisco New Generation Cartel and why he was killed in a Mexican military operation.
Who is ‘el Mencho’ and the Jalisco New Generation Cartel?
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Nemesio “El Mencho” Oseguera Cervantes was a feared drug kingpin, leader of the Jalisco New Generation Cartel (CJNG), one of Mexico’s most violent criminal organizations.
For years, he was among the country’s most wanted fugitives and the United States had offered a $15 million reward for information leading to his arrest.
Born in July 1966 in the state of Michoacán, Oseguera later moved to the US and, in 1994, was convicted in California for conspiracy to distribute heroin.
After serving three years in prison, he returned to Mexico where worked as a police officer in Jalisco but soon resumed criminal activities.
According to the US Treasury Department, “El Mencho” was deeply involved in drug trafficking from the 1990s.
He built up CJNG along with his brother-in-law Abigael González Valencia, leader of Los Cuinis — a family-based cartel operating in Michoacán. The US Drug Enforcement Administration said Los Cuinis served as the financial and logistical arm of CJNG and oversees its “diverse network of money laundering operations.”
Before forming CJNG, Oseguera had served as chief of hitmen for the Milenio Cartel, then affiliated with the Sinaloa Cartel, where he oversaw security and operational violence.
CJNG emerged in the 2010s from the remnants of the Milenio Cartel, according to the DEA.
Oseguera was indicted multiple times in the United States, and in 2022, he was charged with conspiracy to manufacture and distribute methamphetamine, cocaine and fentanyl for importation into the United States, among other offenses.
The DEA said CJNG is “a key supplier of illicit fentanyl” to the US, “reaps billions of dollars in profit from the manufacture of illegal synthetic drugs, as well as being one of main suppliers of cocaine to the US market” and has a presence in over 40 countries.
“It has carried out acts of intimidating violence, including attacks against Mexican military and police with military-grade weapons, the use of drones to drop explosives on Mexican law enforcement, and assassinations or attempted assassinations of Mexican officials,” the State Department said when it designated CJNG as a terrorist organization in February 2025.
