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 organizations over two decades, the only widely known photographs of the man known as “El Mencho” date to earlier arrests on robbery and drug charges in California in the 1980s and early 1990s.
From Michoacan to California
Oseguera Cervantes, 59, was originally from the farming community of El Naranjo in the neighboring state of Michoacan.
He was born Rubén Oseguera Cervantes but later added Nemesio to his name, the likely origin of his nickname “El Mencho,” said Carlos Flores, a researcher at the Center for Research and Higher Education in Social Anthropology.
As a young man, he migrated to the United States and settled in California, where he married into the “Los Cuinis” group led by his 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 worked closely with Los Cuinis, who were linked to drug lord Armando Valencia Cornelio, known as “El Maradona,” leader of the now-defunct Milenio cartel.
In the 1990s, Oseguera Cervantes had contact with a significant organization that trafficked cocaine with Colombian suppliers and had ties to traffickers in Sinaloa state, Flores said. He began working as an armed enforcer for Valencia Cornelio.
As conflicts intensified with rival groups in Michoacan, Valencia Cornelio and González Valencia moved operations to Jalisco and strengthened ties with traffickers in Sinaloa.
The rise of 'El Mencho'
After Valencia Cornelio’s arrest in 2003, González Valencia’s group and Oseguera Cervantes began working for Ignacio “Nacho” Coronel, a financial operator for the Sinaloa Cartel and associate of Joaquín “El Chapo” Guzmán, who is serving a life sentence in the United States.
Óscar Nava Valencia later took control of the Milenio cartel, and the group became enforcers for the Sinaloa Cartel in its fight against the Zetas.
The 2009 capture of Nava Valencia and the 2010 killing of Coronel by the Mexican military deepened divisions within the organization. A faction led by Oseguera Cervantes joined forces with Erik Valencia Salazar, known as “El 85,” to form the Jalisco New Generation Cartel around 2009.
Rapid expansion
In less than two decades, Oseguera Cervantes built a powerful criminal organization with thousands of members. According to the U.S. Drug Enforcement Administration, the cartel operates in 21 of Mexico’s 32 states. Mexican authorities say it has a presence in 36 countries.
Flores attributed the group’s rapid growth in part to security policies under former President Enrique Peña Nieto that weakened the Sinaloa Cartel, including the final capture and extradition of Guzmán to the United States. That shift created space for the Jalisco cartel to expand.
The cartel’s rise alarmed U.S. authorities. In May 2016, Oseguera Cervantes was added to the most wanted list. In 2018, the U.S. State Department offered a $10 million reward for information leading to his arrest, later increasing it to $15 million in 2024. Last year, President Donald Trump designated the Jalisco New Generation Cartel and five other Mexican cartels as foreign terrorist organizations.
Flores said that despite having only a secondary education, Oseguera Cervantes had the skill and intelligence to build an organization that secured support from local and federal officials and diversified beyond drug trafficking into extortion, real estate, fuel theft and other ventures.
As his death underscored, Flores said, he also had “a capacity for violent action” that helped him build his criminal empire.