How El Mencho built a global cartel before his death in Jalisco

Mexico City: Like many drug lords, Nemesio Oseguera Cervantes kept a low profile until he was killed by the Mexican army Sunday in the western state of Jalisco.

Despite building one of Mexico's most powerful criminal organisations over two decades, the only known photographs of the man known as “El Mencho” come from his earlier arrests on robbery and drug charges in California in the 1980s and early 1990s.

The Mexican army killed Oseguera Cervantes on Sunday in Tapalpa, Jalisco state, as special forces attempted to capture him.

From Michoacan to California

Oseguera Cervantes, 59, was originally from the farming community of El Naranjo, in the neighbouring state of Michoacan.

He was born Rubén Oseguera Cervantes, but for unknown reasons later added Nemesio, the origin of his nickname “El Mencho,” said Carlos Flores, a researcher with the Centre for Research and Higher Education in Social Anthropology.

When he was young, Oseguera Cervantes migrated to the United States and settled in California. There, he married into the “Cuinis” gang led by his new brother-in-law, Abigael González Valencia, also known as “El Cuini.”

Return to Mexico

After serving three years in prison for heroin trafficking, Oseguera Cervantes was deported to Mexico. Back in Michoacan, he began working more closely with “Los Cuinis,” which were tied to drug lord Armando Valencia Cornelio, alias “El Maradona,” leader of the now defunct Milenio cartel.

That's when in the 1990s, Oseguera Cervantes “was in contact with a significant organization” that trafficked cocaine with Colombians and had ties to traffickers in Sinaloa state, Flores said. He began working as a gunman for Valencia Cornelio.

As conflict grew with other groups in Michoacan, Valencia Cornelio and González Valencia moved their operations to Jalisco and strengthened their relationship with Sinaloan drug traffickers.

The rise of El Mencho

After Valencia Cornelio's arrest in 2003, González Valencia's crew and Oseguera Cervantes began to work for Ignacio “Nacho” Coronel, a finance operator for the Sinaloa Cartel and associate of Joaquín “El Chapo” Guzmán, the former cartel leader now serving a life sentence in a U.S. prison.

Óscar Nava Valencia took control of the Milenio cartel and they became the enforcers for the Sinaloa Cartel against the hyperviolent Zetas.

In an example of how taking out cartel leaders can generate more gangs, Nava Valencia's capture in 2009 and the Mexican military's killing of Coronel a year later, deepened divisions within the organisation. A faction led by Oseguera Cervantes joined with Erik Valencia Salazar, alias “El 85,” to form the Jalisco New Generation Cartel around 2009.

Jalisco Cartel's explosive growth

In less than two decades, Oseguera Cervantes consolidated a powerful criminal organisation with thousands of members, which, according to the U.S. Drug Enforcement Administration, has a presence in 21 of Mexico's 32 states. Mexican authorities say the cartel operates in 36 countries.

Flores attributed that rapid growth to various factors, including the security policies of former President Enrique Peña Nieto that weakened the Sinaloa Cartel, including the final capture of Guzmán and his extradition to the US. That opened more space for the Jalisco cartel to expand.

The cartel's growth alarmed the United States. In May 2016, it added Oseguera Cervantes to its most wanted list. Two years later, the US State Department offered a $10 million reward for information leading to his arrest. In 2024, they raised it to $15 million. Last year, U.S. President Donald Trump designated the Jalisco New Generation Cartel and five other Mexican cartels as foreign terrorist organisations.

Flores said that even with a secondary education, Oseguera Cervantes had the savvy and intelligence to build an organisation that had the support of local and federal officials, and that diversified beyond drug trafficking into extortion, real estate, fuel theft and other businesses.

As his death demonstrated, he also had “a capacity for violent action” that helped him build his empire, Flores said.