2 More Inmates Killed in a New Fight at Mazatlán’s El Castillo Prison, a Day After 10 Died — El Financiero Says Thursday’s Gunmen Were After Los Chapitos’ ‘El Owen’
A second fight inside El Castillo prison in Mazatlán, Sinaloa, killed two more inmates on Friday, Oct. 9, 2026, a day after a shooting there left 10 dead, Sinaloa’s Public Security Secretariat (SSP) said, according to Milenio, Excélsior and Crónica. That brings the toll to 12 in two days. El Financiero, citing unnamed security sources, reported that Thursday’s attackers were after Eduardo Jonathan Martínez Larios, “El Owen,” whom it describes as a member of the Los Chapitos faction of the Sinaloa Cartel. His name was on the state’s list of the nine inmates killed Thursday.
What the state says about Friday’s fight
In a post on X quoted by Milenio, the SSP said “a fight was recorded inside a module in which, regrettably, 2 persons deprived of liberty lost their lives.” The prison’s management reported the clash, Milenio said. Excélsior reported it happened in the same module as Thursday’s violence. Officials said an interagency security group brought the situation under control, the rest of the inmates are “fine,” and the state prosecutor’s office was notified. The SSP did not give the victims’ names, the time, or a cause, Milenio and Crónica reported.
At her morning news conference, President Claudia Sheinbaum said, “We are in contact with the governor (Graciela Domínguez) and security will be reinforced,” El Financiero reported. Federal officials are helping state authorities, Excélsior said.
Who ‘El Owen’ is, per El Financiero
El Financiero’s Mazatlán correspondent, Carlos Velázquez, wrote that El Owen belongs to the “Hermanos Martínez” clan, which it says is blamed for rising violence in Mazatlán, Concordia, Escuinapa and Rosario. His brother Óscar Luciano Martínez Larios, “El Casco,” is described as the alleged Los Chapitos regional boss in southern Sinaloa and is a fugitive. Another brother, Gabriel Nicolás Martínez Larios, “El Gabito,” was arrested in June, the outlet said. Sinaloa officials have not publicly confirmed that El Owen was the target. They have described Thursday’s shooting as a fight between inmates.
El Financiero also reported the prison holds 2,217 inmates, above its official capacity of 1,800. Excélsior and Sinaloa officials said the child killed Thursday was 2 years old. One earlier El Financiero headline said 11.
Línea Directa’s Oct. 8 video report on Thursday’s clash:
Sources
- Milenio (Manuel Aceves): Nueva riña al interior del penal de Mazatlán deja dos muertos; suman 12 en dos días (Oct. 9, 2026)
- Excélsior (Jimena Campuzano): Nueva riña en penal de Mazatlán deja 2 muertos (Oct. 9, 2026)
- Crónica (Eidalid López): Segunda riña en penal de El Castillo, Sinaloa en menos de 24 horas (Oct. 9, 2026)
- El Financiero (Carlos Velázquez): Balacera en penal de Mazatlán: El objetivo era asesinar a ‘El Owen’ (Oct. 9, 2026)
- El Financiero: Nueva riña en penal El Castillo deja 2 reos muertos (Oct. 9, 2026)
- El Financiero: Sheinbaum ‘meterá en cintura’ a penales de Sinaloa tras nueva riña (Oct. 9, 2026)
- Photos: Cuartoscuro, via Excélsior and El Financiero. Video: Línea Directa.
Reported Oct. 9, 2026, from the outlets above. The Narco Blog has not independently confirmed these details. The report that El Owen was the target comes from El Financiero’s unnamed security sources, not an official statement. No one has been charged, and the names of Friday’s two victims had not been released.