Cop-Turned-Drug Lord: Mexico’s ‘El Mencho’ and a Bloody Legacy

Nemesio Oseguera Cervantes — better known as “El Mencho” — rose from a troubled youth and former police officer to become one of Mexico’s most feared drug lords. As the leader of the powerful Jalisco New Generation Cartel (CJNG), Oseguera built a criminal empire marked by extreme violence, rapid expansion, and direct confrontations with Mexican security forces.

Early Life and Arrest in the United States

Born in the rural state of Michoacán, Oseguera migrated to the United States as a young man in search of work. During his time there, he was arrested on drug-related charges and later served several years in a U.S. prison. After completing his sentence, he was deported back to Mexico.

His deportation marked a turning point.

From Police Officer to Cartel Operative

Upon returning to Mexico, Oseguera briefly joined local law enforcement — a move that would later help him understand the inner workings of police operations. However, he soon left the force and entered the criminal underworld.

He became affiliated with the Milenio Cartel, a criminal group that operated as a satellite organization of the powerful Sinaloa Cartel. Through strategic alliances and calculated violence, Oseguera steadily climbed the ranks.

Rise of the Jalisco New Generation Cartel (CJNG)

After internal fractures weakened the Milenio Cartel, Oseguera seized the opportunity to form what would become the CJNG around 2010. Under his leadership, the group rapidly expanded across multiple Mexican states and established international trafficking routes.

The CJNG became known for:

• Highly militarized tactics

• Public displays of force

• Attacks on security personnel

• Control over synthetic drug production, particularly methamphetamine and fentanyl

Mexican authorities and the U.S. government have labeled CJNG as one of the most dangerous and fastest-growing criminal organizations in the world.

Violent Confrontations with the State

El Mencho’s cartel gained notoriety for its direct attacks on government forces. In 2015, CJNG fighters shot down a Mexican military helicopter during a security operation — a rare and shocking escalation in cartel violence.

Oseguera remains one of the most wanted fugitives, with multi-million-dollar rewards offered for information leading to his capture. Despite numerous operations, he has managed to evade arrest for years.

A Legacy Written in Blood

Under El Mencho’s command, the CJNG has been linked to mass killings, forced disappearances, and territorial wars with rival groups. His rise reflects a broader shift in Mexico’s organized crime landscape — from older cartel hierarchies to more aggressive and decentralized networks.

While several of his family members and associates have been arrested, Oseguera himself continues to symbolize both the resilience and brutality of modern cartel power.