He was the leader of the assassins but he needed to marry Rosalinda to move up in the cartel: who was “El Mencho”

Although he is now dead, he continues to cause fear among the living, due to the riots that ensued after his death.

Dead. Who was “El Mencho”, the feared cartel leader accused of flooding the US with fentanyl

_{by Gonzalo Zegarra e Rocío Muñoz-LedoCNN}

Nemesio “El Mencho” Oseguera Cervantes was a feared Mexican drug lord and leader of a ruthless cartel accused of masterminding efforts to introduce fentanyl into the United States.

A former police officer, Oseguera became one of the most wanted fugitives in the world, with the United States offering a reward of 15 million dollars (about 13.8 million euros) for information leading to his capture.

Oseguera, who founded and led the Jalisco Cartel New Generation (CJNG), was an elusive figure and was considered Mexico’s most powerful cartel boss since Sinaloa Cartel leader Joaquín “El Chapo” Guzmán was detained last decade.

Born in July 1966 in the western state of Michoacán, Oseguera later moved to the United States and has been deeply involved in drug trafficking since the 1990s, according to the U.S. Drug Enforcement Agency (DEA). In 1994, he was convicted in California of conspiracy to distribute heroin and served three years in a US prison.

After returning to Mexico, he worked as a police officer in the western state of Jalisco, but quickly resumed criminal activities, consolidating his influence in the drug trafficking underworld until he became the leader of one of the most powerful and violent criminal empires in the country.

Wanted by authorities in Mexico and the USA, Oseguera, or “El Mencho”, maintained a low profile — to the point that only a few photographs of him exist.

on Sunday, in a Mexican military operation in Tapalpa, in the western coastal state of Jalisco, .

On the most wanted list

Oseguera built a long career marked by brutality before forming the CJNG. For a time, he was chief killer — the main enforcer — of the Milenio Cartel, before overseeing the security and operational violence of the notorious Sinaloa Cartel, whose former leader, Guzmán, is serving a life sentence in the United States.

According to the DEA, the CJNG emerged in the 2010s from the remnants of the Milenio Cartel, which fragmented into a power vacuum following the capture of its leader, Óscar Nava Valencia, in 2009.

Oseguera built the group together with Abigael González Valencia, leader of Los Cuinis — a family-based cartel operating in Michoacán that served as the financial and logistical arm of the CJNG and oversaw its “diverse network of money laundering operations,” according to the DEA.

But it was through his marriage to Abigael’s sister, Rosalinda González Valencia, that Oseguera gained true influence in the new structure.

“In reality, El Mencho came to lead the cartel through a strategy of diplomacy via marriage,” explained public security analyst David Saucedo to CNN en Español. “He was, in fact, the leader of ‘Nacho’ Coronel’s assassins. [líder do Cartel de Sinaloa]but he didn’t have the lineage that Rosalinda, his wife, had”, he added.

The rising cartel quickly expanded its sphere of influence, securing a significant presence throughout Mexico and becoming a central player in the global drug trade.

It is an extremely violent organization, responsible for assassination attempts against Mexican government officials and for homicides against rival drug trafficking groups and agents of the Mexican security forces, according to the US State Department.

The cartel demonstrated its firepower in May 2015, when it responded to a security operation with simultaneous roadblocks in several municipalities and shot down a military helicopter. Three soldiers died in the clashes.

The following year, the group was identified as responsible for the audacious kidnapping of one of Guzmán’s children, in a popular restaurant in Puerto Vallarta. He was released a week later.

Shortly thereafter, the DEA placed “El Mencho” on its most wanted list.

International Drug Network

The CJNG is heavily involved in the production and trafficking of methamphetamine and fentanyl, with links to suppliers of precursor chemicals in China, and controls several seaports for importing these chemicals, according to US authorities.

The cartel is “one of the leading suppliers of illicit fentanyl” to the United States, raking in “billions of dollars in profits,” as well as being one of the largest suppliers of cocaine, according to the DEA.

The group has contacts in more than 40 countries, including the Americas, as well as Australia, China and Southeast Asia, according to the US State Department.

Mexico was under pressure from US President Donald Trump to do more to limit the flow of drugs into the United States.

The US classified the CJNG as a terrorist organization in February 2025, and Oseguera has previously been charged several times in the United States, including in 2022, when he was formally charged with conspiracy to manufacture and distribute methamphetamine, cocaine and fentanyl intended for importation into the US.

The death of “El Mencho”, on Sunday, caused instability in the country. But this does not necessarily mean that the CJNG’s multimillion-dollar drug trade will come to a standstill.

According to the DEA, the group is structured as a franchise model and, according to Eduardo Guerrero, director of the Mexican consultancy group Lantia Intelligence, it is made up of around 90 organizations.

“This fragmentation means that a more complex and sophisticated strategy will be needed to weaken and dismantle them,” Guerrero told CNN earlier this year.

The Mexican Armed Forces and police, with the support of information and equipment from the United States, have already tried to neutralize major drug trafficking leaders in the past. But others emerged to take their place, and tons of drugs continued to cross the North American border.