After El Mayo: Murders in Sinaloa rise 400% the year after

After El Mayo: Murders in Sinaloa rise 400% the year after

Mexico had a quiet Sunday on August 10, but things were anything but usual in the northwestern state of Sinaloa. 17 murder cases were recorded that day, which is one murder every 85 minutes. According to Mexican government statistics, this was the most violent day of 2025 in Sinaloa, surpassing all other states. Sunday's killings are part of a worrying wave of violence that has swept the region following the surprise arrest of Ismael "El Mayo" Zambada, one of the longtime leaders of the Sinaloa Cartel - one of Mexico's oldest and most violent criminal organizations.

Rise in violence in Sinaloa

Since his arrest, murder cases in Sinaloa have increased by more than 400%, a CNN analysis of public data shows. This analysis also reveals discrepancies between the figures provided by the Sinaloa Prosecutor, the Mexican federal authorities, and the monitoring organization ACLED (Armed Conflict Location & Event Data). Historically, Mexican authorities have often underreported the number of casualties during violent conflicts in the region.

Even behind closed doors, U.S. defense and law enforcement officials remain wary of Mexico's murder numbers, according to a source familiar with those conversations. El Mayo's arrest on July 25, 2024 in El Paso, Texas, sparked an internal conflict between rival factions of the Sinaloa Cartel, pushing the people of Sinaloa between the battle lines in a dispute that is disrupting daily life and forcing major chains and family-owned businesses to close.

Internal conflicts after the arrest of El Mayo

The rise in violence in Sinaloa stems from fighting between rival factions of the Sinaloa cartel that broke out after Zambada's arrest, explains Victoria Dittmar, investigator and project manager at InSight Crime. Intense fighting broke out between his followers – the Mayitos – and the allies of Joaquín “El Chapo” Guzmán. These fights have been compounded by ongoing clashes between the Sinaloa Cartel's smaller factions, which is also reflected in ACLED's data.

In a statement issued by his lawyer, El Mayo claimed that he was deceived by one of El Chapo's sons, Joaquín Guzmán López, and a leader of the Sinaloa Cartel, who lured him to the United States under false pretenses. According to Zambada, the meeting presented as a real estate investment opportunity ended with his arrest in El Paso.

The daily life of the residents of Culiacán

The violence in Sinaloa has not only had a statistical impact, but has significantly disrupted the daily lives of residents. In Culiacán, the constant fear of armed conflict is forcing large chains and small family businesses to reduce their opening hours or close completely. A small business owner who ran her grandmother's decades-old restaurant was forced to close.

“There were days when a customer might come, if at all... because people don't go out at night anymore, even today,” says Sonia, who wishes to remain anonymous for security reasons. Like many others in Culiacán, she had to adapt to a new reality and implement a “self-curfew.” “We, the citizens, decided a few months ago to only go out at certain times,” she explains.

The violence in Sinaloa has also resulted in a number of violent incidents in urban areas. Videos on social media show shootings in broad daylight and clashes between armed groups and security forces.

Political reactions and security strategies

On the first anniversary of El Mayo's arrest, Mexican President Claudia Sheinbaum said her government was taking action: "We are working on it and we will bring peace to Sinaloa." Still, for Sonia, this commitment feels distant: "You see military convoys everywhere, but there is no real strategy. In some areas there are shootings every day, and the authorities only come hours later."

Sinaloa remains the weak point in Mexico's security strategy, with at least 571 civilian casualties in 2025. Targeted killings of civilians have already surpassed the 2024 total, ensuring this year will be one of the deadliest in Sinaloa's history.

For many residents, August Sunday was another expression of the ongoing war that continues with no hope of ending.