Ruben “Nemesio” Oseguera Cervantes, widely recognized as “El Mencho,” the formidable leader of Mexico’s Jalisco New Generation Cartel (CJNG), was killed on Sunday during a military operation, according to Mexican authorities. Oseguera gained significant influence following the capture of Joaquin “El Chapo” Guzman, the former leader of the competing Sinaloa Cartel.

Under Oseguera’s command, the CJNG rapidly expanded its influence throughout Mexico, fiercely competing with the Sinaloa Cartel for control over critical drug trafficking routes into the United States. This expansion solidified the CJNG’s reputation as one of the most powerful drug trafficking organizations globally.

The death of Oseguera signifies the downfall of one of the most powerful and elusive cartel leaders since the era of El Chapo. Both U.S. and Mexican officials had long considered him a key player in the trafficking of fentanyl and methamphetamines.

Deputy Secretary of State Christopher Landau announced that Mexican security forces had successfully eliminated Oseguera, describing it as a significant triumph.

Oseguera, known as El Mencho, was killed during a military operation in the state of Jalisco on Sunday. (Source: Drug Enforcement Administration)

“I have just received confirmation that Mexican security forces have taken down ‘El Mencho,’ one of the most violent and merciless drug lords,” Landau wrote on X. “This development is a major victory for Mexico, the United States, Latin America, and the entire world. The forces of good have prevailed over evil.”

A senior State Department official separately confirmed Oseguera’s death and referred to Landau’s remarks.

The State Department issued a travel alert Sunday for multiple areas of Mexico, urging U.S. citizens to shelter in place due to “ongoing security operations and related road blockages and criminal activity,” including parts of Jalisco, Tamaulipas, Michoacan, Guerrero and Nuevo León.

A soldier stands guard by a charred vehicle after it was set on fire, in Cointzio, Michoacán state, Mexico, Sunday, Feb. 22, 2026, following the death of the leader of the Jalisco New Generation Cartel, Nemesio Oseguera, known as “El Mencho.”  (Armando Solis/AP Photo)

Oseguera, a former police officer, helped found CJNG around 2009 after splintering from the Sinaloa Cartel. In the years that followed, the group evolved from a regional faction into one of the most dominant trafficking networks in the world.

U.S. authorities steadily increased the reward for information leading to his capture, at one point offering up to $15 million, placing him among the most wanted fugitives globally.

Former U.S. Drug Enforcement Administration official Paul Craine once described Oseguera as “public enemy No. 1” and said he commanded an “army of thousands.”

The Drug Enforcement Administration in Atlanta seized more over 1,000 pounds of meth linked to the violent ‘Cartel Jalisco New Generation.’ (Fox News)

Authorities have linked him to coordinated attacks on Mexican security forces, including a 2015 assault in Jalisco in which cartel gunmen used rocket-propelled grenades to bring down a military helicopter.

Over time, CJNG gained a reputation for projecting strength through public displays of force and social media messaging, reinforcing its position as one of Mexico’s most feared criminal organizations.

His death removes one of the most dominant figures in Mexico’s criminal underworld and could reshape the balance of power among rival cartels.