Mexican authorities tracked down and killed Nemesio Oseguera Cervantes, the notorious leader of the Jalisco New Generation Cartel known as "El Mencho," by surveilling one of his romantic partners, who led them to a secluded mountain cabin where the operation unfolded fatally on February 22, 2026.

El Mencho
El Mencho

Defense Secretary General Ricardo Trevilla Trejo detailed the events during a February 23 press conference, revealing that intelligence efforts focused on a trusted associate of one of Oseguera's romantic partners. On February 20, this individual escorted the woman to a property in Tapalpa, Jalisco, for a meeting with the cartel boss. The woman departed the next day, but Oseguera remained with his security detail.

Trevilla described the location as a wooded mountainous area, accessible primarily by ground forces with limited air support to avoid detection. When special forces raided the site on February 22, a firefight erupted. Oseguera was mortally wounded and died en route to medical care in Mexico City. Four cartel members were killed on site, and others were injured.

The operation stemmed from years of pursuit by Mexican and U.S. authorities. Oseguera, 59, headed the CJNG—one of the world's most powerful and violent cartels—responsible for trafficking fentanyl, methamphetamine, cocaine, and heroin into the United States and beyond. He faced multiple U.S. indictments for drug trafficking and organized crime, with a $10 million reward offered by the State Department.

Mexican officials credited U.S. intelligence with providing "very important additional information" that helped pinpoint the location after tracking the romantic partner's movements. The partner has not been publicly identified or charged, though some reports and leaked documents from past Guacamaya Leaks hacks have linked a woman named Guadalupe Moreno Carrillo to Oseguera's inner circle following the 2021 arrest of his wife, Rosalinda González Valencia.

González Valencia, arrested twice on money laundering and organized crime charges, was reportedly released in 2025 after serving time. She had played a key role in the cartel's financial arm, Los Cuinis. Authorities have not confirmed whether Moreno or another partner was involved, emphasizing operational security.

The raid triggered immediate violence across Jalisco and neighboring states. Cartel gunmen torched vehicles, blocked highways, set fires in Guadalajara and Puerto Vallarta, and clashed with security forces. Dozens of businesses were looted or burned, and several deaths were reported in the initial chaos. President Claudia Sheinbaum condemned the retaliation and pledged continued operations against organized crime.

Oseguera's death marks a significant blow to the CJNG, which rose to dominance through extreme violence, territorial expansion, and fentanyl production. Analysts warn of potential fragmentation or power struggles. Possible successors include stepson Juan Carlos Valencia González (alias "El 03"), who oversees operations, or other family members. González Valencia could influence leadership decisions, though her public profile and legal history complicate any direct role.

The U.S. welcomed the development, with officials noting it disrupts a major fentanyl pipeline. The DEA and State Department had long prioritized Oseguera's capture or death. His killing follows similar high-profile operations against other cartel figures, though CJNG's decentralized structure may allow it to persist.

As investigations continue, Mexican forces remain on high alert for reprisals. The government has not released further details on the romantic partner's identity or current status, citing ongoing security concerns. The case underscores the role of personal relationships in intelligence gathering against elusive high-value targets in Mexico's drug war.