He was known as “El Mencho” and was one of the most wanted men on the continent. The leader of the Jalisco New Generation Cartel, whose full name was Nemesio Rubén Oseguera Cervantes, was killed Sunday in a military operation in western Mexico.
Violent clashes broke out following the operation that led to Oseguera Cervantes’ death, during which six other people were killed and several arrested. Mexican authorities said they seized armored vehicles, rocket launchers and other weapons from alleged cartel members. Three members of Mexico’s military were also wounded in the operation.
The violence that broke out Sunday is part of a long pattern of clashes between Mexican authorities and the cartel, CJNG.
Oseguera Cervantes had been wanted for years by the United States, which has alleged that he and CJNG traffic large quantities of fentanyl and other drugs into the U.S. At the time of his death, the State Department was offering a $15 million reward for information leading to his arrest.
U.S. Drug Enforcement Administration
Who is Nemesio Rubén Oseguera Cervantes?
Born in Mexico, Oseguera Cervantes entered the U.S. illegally in the 1980s and lived in California for years. He was eventually arrested on drug charges and deported back to Mexico, but he returned to the U.S. illegally.
He was again arrested on drug charges in 1992 and, after serving three years in prison and being released on parole, was deported to Mexico a second time, according to BBC News and other reports.
Back in Mexico, he began his rise to the top of one of the country’s most powerful cartels.
El Mencho and CJNG’s violent history in Mexico
After splintering off from the Milenio Cartel, U.S. officials say Oseguera Cervantes and others formed CJNG around 2011.
“CJNG is heavily involved in the manufacturing, trafficking, and distribution of illicit drugs, such as fentanyl, methamphetamine, and cocaine, as well as maintaining a vast money laundering operation,” according to the U.S. Drug Enforcement Administration.
In 2019, the DEA estimated CJNG was responsible for at least one-third of all the drugs entering the U.S. from air and sea.
Former DEA agent Matthew Donahue told CBS News at the time that Oseguera Cervantes was “the number one priority for DEA and frankly for federal law enforcement in the United States.”
President Trump, in February of last year, signed an executive order designating CJNG and seven other cartels as foreign terrorist organizations. Then, in May, federal prosecutors used that designation to charge 39-year-old Maria Del Rosario Navarro-Sanchez for allegedly providing grenades to CJNG.
“He has got an enormous amount of weapons, RPGs, 50 caliber weapons. He basically has his own SWAT teams,” Donahue said.
Those kinds of weapons have been used to assert, expand and maintain the cartel’s control throughout the country in violent and often bold fashion.
In 2020, the cartel attempted to assassinate Mexico City Police Chief Omar García Harfuch, who now serves as Mexico’s secretary of Security and Civilian Protection. While traveling to a meeting in an armored SUV, García was attacked by CJNG members who had high-powered rifles, grendades and body armor, according to Mexico News Daily. He survived, but two of his bodyguards and an uninvolved woman were killed.
U.S. prosecutors have also alleged that in 2015, the cartel shot down a Mexican military helicopter with an RPG during a campaign by Mexico to target cartels in Jalisco.
CJNG’s violence was also often more targeted.
Cristian Fernando Gutierrez-Ochoa, a former high-ranking cartel leader, is alleged to have kidnapped two Mexican Navy members in 2021 in an effort to get El Mencho’s wife released after she herself had been arrested by Mexican authorities. According to prosecutors, El Mencho told people that he killed Gutierrez-Ochoa for lying, but Gutierrez-Ochoa actually faked his death and fled from Mexico to Riverside, California. Oseguera Cervantes’ wife was eventually released from prison in February 2025.
CJNG has been accused of using fake job advertisements in an attempt to lure new members, then forcing the unsuspecting applicants to join the cartel. The cartel is alleged to have tortured or killed those who tried to resist or escape. In March, charred bones, shoes and clothing were found by a group of people looking for missing relatives found at what is believed to be a training ground for CJNG.
El Mencho’s son, Rubén Oseguera — known as “El Menchito” — was sentenced in March 2025 to life in prison after he was convicted in the U.S. on drug and weapons charges.
“El Menchito led the Jalisco Cartel’s efforts to use murder, kidnapping, and torture to build the Cartel into a self-described ’empire’ by manufacturing fentanyl and flooding the United States with massive quantities of lethal drugs,” former U.S. Attorney General Merrick Garland said in September 2024.
Prior to his death, Oseguera Cervantes had also been indicted in the U.S. multiple times. His most recent indictment came in April 2022, when he was charged with conspiracy to manufacture and distribute methamphetamine, cocaine, and fentanyl for importation into the U.S. and use of a firearm during and in relation to drug trafficking crimes, according to the State Department.
