Óscar Luciano Martínez Larios—alias “El Casco” or “El 81”—is the last fugitive member of the Martínez Larios brothers’ clan, a family structure that maintained control over southern Sinaloa for the *Los Chapitos* faction of the Sinaloa Cartel for at least a decade.
The operation launched this weekend by the Navy in the municipalities of El Rosario and Concordia—which resulted in 10 alleged cell members killed, three arrests, and the death of a marine—had his capture as a priority objective.
According to reports by *Milenio*, the operation targeting the *Los Chapitos* operative began on Saturday, July 4, after residents reported the presence of armed civilians near communities located between Agua Verde and Chametla, in the municipality of Rosario. Navy personnel responded to the report and encountered members of an armed group, sparking a confrontation.
A priority objective lay behind the deployment: locating “El Casco” or “El 81.” Following the shootout, federal forces expanded the operation to include aerial reconnaissance and ground patrols in mountainous areas used as transit routes by armed cells in southern Sinaloa.
The mobilization involved the coordinated participation of the Navy, the Mexican Army, the National Guard, and the Secretariat of Security and Citizen Protection, as well as state law enforcement agencies. Clashes between rival groups in the area had already caused the displacement of families and involved attacks using improvised explosives and drones as part of the criminal conflict.
President Claudia Sheinbaum confirmed at a press conference on Monday that Navy personnel had been the target of two consecutive attacks. She explained that several officers were wounded in the first incident and that the personnel were attacked again the following day. Details regarding the exact number of injured personnel, he said, would be provided by the Security Cabinet.
