# Violence at El Castillo Penitentiary in Mazatlán

> Live situation record from CLSTR: https://clstr.news/situations/violence-at-el-castillo-penitentiary-in-mazatln
> Updated: 2026-10-10T16:04:09.000Z. Sources: 81. Developments: 3.

On September 24, 2026, a verbal dispute escalated into a physical confrontation in the workshop area of the El Castillo Penitentiary Center in Mazatlán, Sinaloa, resulting in the deaths of two inmates. On October 8, 2026, the facility experienced a violent riot involving gunfire that caused significantly higher casualties. Ten people died, including nine inmates and a visiting minor, reported to be a two-year-old boy visiting with family. The riot also left 16 inmates injured. An inter-institutional group, including the Mexican Army, Navy, and National Guard, intervened to secure the facility. Authorities have since regained control but suspended all visits to the penitentiary as a preventive measure while investigations continue. In a separate incident at the same facility on the following Friday, two additional inmates were reported dead following another clash. This brings the total death toll at the prison to 12 within a 48-hour period. Security forces reported that inmates utilized both firearms and knives during the unrest. The Sinaloa State Prosecutor's Office has launched an investigation into intentional homicide to determine the causes of the clashes. Additionally, the Sinaloa State Human Rights Commission is conducting an inquiry into potential rights violations. These events occur amid sustained violence in Sinaloa driven by internal conflicts between Sinaloa Cartel factions, specifically ‘Los Chapitos’ and ‘La Mayiza.’ In response to the escalating violence, the Mexican federal government, supported by President Claudia Sheinbaum, has announced plans to construct a new, modern penitentiary in Sinaloa using federal investment to address the ongoing security crisis and prevent further cartel-related influence within the correctional system. Security Secretary Omar García Harfuch stated the new facility is being built to provide the infrastructure necessary to ‘increase control and reduce violence.’ Interim governor Graciela Domínguez Nava has agreed to provide the land for the new construction.

## Claims

- Ten people died in a fight at the El Castillo Penitentiary Centre, including nine inmates and one minor visitor. (disputed by 28 sources)
- Two violent clashes occurred in a Sinaloa prison this week, resulting in 12 deaths. (disputed by 5 sources)
- Security forces, including the army and National Guard, restored control of the El Castillo Penitentiary. (corroborated by 26 sources)
- Prison visits have been suspended as a precaution. (corroborated by 26 sources)
- Inmates reportedly used firearms during the riot. (corroborated by 15 sources)
- Two inmates died in a separate fight at the El Castillo prison on Friday. (corroborated by 5 sources)
- The state prosecutor opened investigations for intentional homicide following the prison violence. (corroborated by 5 sources)
- The Mexican government will build a new detention center in Sinaloa. (corroborated by 5 sources)
- The clashes took place in a prison in the city of Mazatlán. (corroborated by 5 sources)
- The National Guard and prison service personnel are being deployed to enhance security at the current facility. (corroborated by 5 sources)

## Timeline

### 2026-10-10: Sinaloa to receive new prison after 12 deaths in Mazatlán clashes

Mexico will build a new prison in Sinaloa following two violent clashes at Mazatlán's El Castillo facility that left 12 people dead, including a child visitor.

11 sources. https://clstr.news/cluster/sinaloa-to-build-new-prison-after-deadly-clashes-kill-12

### 2026-10-08: El Castillo Penitentiary: 12 dead in Sinaloa prison violence

At least 12 people, including nine inmates and a minor visitor, died in two separate violent clashes at the El Castillo Penitentiary in Sinaloa, Mexico, within 48 hours.

70 sources. https://clstr.news/cluster/mazatln-prison-riot-leaves-10-dead-including-a-visiting-child

### 2026-09-24: Mazatlán prison: Two inmates die after fight in workshop area

Two inmates died following a physical altercation in the workshop area of the El Castillo Penitentiary Center in Mazatlán, Sinaloa.

3 sources. https://clstr.news/cluster/mazatln-prison-two-inmates-die-after-fight-in-workshop-area

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Cite as: Violence at El Castillo Penitentiary in Mazatlán. CLSTR, https://clstr.news/situations/violence-at-el-castillo-penitentiary-in-mazatln