It’s been nearly a year since her younger sister Cecilia disappeared, and Nadia Berrelleza barely sleeps.
Instead, she spends her nights seeking clues, retracing Cecilia’s last movements and scrutinizing messages, photographs and videos claiming to reveal her fate.
One image she received showed a young woman with long, curly black hair — just like Cecilia’s — kneeling and blindfolded, her hands bound, surrounded by armed men. Investigators said the image was generated by A.I. Another video sent on Facebook showed a woman being sexually assaulted. The sender demanded a reward.
“I know her face perfectly; I could never have believed it was her,” Ms. Berrelleza said. “But it’s still so horrible to see that.”
Cecilia Berrelleza, 31, went missing in July 2025 after going to lunch with friends in Mazatlán, a coastal city in the Mexican state of Sinaloa. Since then, Nadia has appealed to the authorities and the public, even offering her car in desperation as a reward for Cecilia’s return. The attention, she said, has brought a stream of tips, but also opportunists trying to extort her with false claims about Cecilia’s fate.
The disappearance is part of a wave of violence that has made Sinaloa state the most dangerous in the country for women. It also coincides with a cartel war between two factions of the Sinaloa Cartel that has weakened security and terrorized the state for two years. The fighting has become so pervasive that the boundaries between domestic violence, gender violence and cartel retaliation often overlap.
Last year, 105 women were killed in Sinaloa, the highest toll in 14 years and nearly double the previous year’s total, while an additional 299 disappeared. Seventy-three of those killings were investigated as femicides, the term for gender-motivated killings. As of July, Sinaloa again led the country in the killings of women, while 153 women have disappeared.
Across the state, women are killed by their husbands or partners inside their homes. Girls are gunned down intentionally in broad daylight or caught in the crossfire as henchmen from rival factions wage war. Some disappear. Others are abducted, tortured and found in clandestine graves, or never found at all.
Most of these deaths and disappearances remain unsolved, as investigators stretched thin by the cartel war struggle to keep pace, experts say. Lydia Ojeda, a researcher at the Autonomous University of Sinaloa who studies femicides, found in an analysis that only 8 percent of all femicide cases between 2015 and 2026 resulted in a conviction.
That figure mirrors a broader crisis in Mexico, where roughly 95 percent of violent crimes, including homicides, go unsolved, according to research groups.
This impunity often pushes relatives to become investigators, detectives and search parties themselves, which can be dangerous work.
Once, following a tip that Cecilia was being forced to work for the cartel, Ms. Berrelleza said she had driven to a ranch outside Mazatlán disguised as a man, only to find herself surrounded by armed lookouts on motorcycles. She left immediately.
Another time, after hearing that her sister was being held in a stash house, Ms. Berrelleza said she had disguised herself as a homeless person, pushing a cart while pretending to talk to herself to investigate the house. The police later raided the house and found guns and drugs, but no sign of Cecilia, Ms. Berrelleza said.
“This is a nest of the snakes,” she said. “The good guys are outnumbered by the bad guys, and the good guys and the authorities are afraid. No one can really help us.”
Ms. Berrelleza has put together a theory of what happened to her sister.
On the day she disappeared, Cecilia went to lunch with three female friends. One of them then drove the group to her boyfriend’s house, according to Ms. Berrelleza, where Cecilia and another of the friends were recorded by street cameras being handcuffed and driven away in a car.
Ms. Berrelleza said she believes the woman who drove Cecilia worked for one of the Sinaloa Cartel factions. She believes the woman recruited young women with promises of luxury, travel and money before delivering some of them to cartel members for sexual exploitation. But the woman is not being investigated as a suspect. According to the case file, she claims she too was kidnapped and released after three days.
The local police and attorney general’s office in Sinaloa declined to comment on the case.
The circumstances surrounding Cecilia’s disappearance remain unclear. But her sister’s account shows how women are increasingly drawn into the cartel underworld as recruiters, couriers or accomplices while also becoming targets, sometimes blurring the line between victim and perpetrator.
Researchers and women’s rights advocates say that Mexico’s broader security crisis has resulted in violence against women slipping down the state’s list of priorities, creating more opportunities for perpetrators to act with greater impunity and giving victims fewer places to turn.
“It is a perfect storm that turns women into easy prey,” said Ms. Ojeda. “Whether the aggressor is a cartel member or an ex-husband, the conditions are always the same: impunity, institutional neglect and a society consumed by violence.”
I interviewed Ms. Ojeda last month in Culiacán, Sinaloa’s capital. At exactly the same time, a gunman walked up to a 23-year-old woman sitting outside a flower shop across the city and shot her in the head.
Similar episodes occur routinely across the city.
In March 2025, Vivian Karely Aispuro, 26, went to a party with her sister and friends. She never made it home. Seventeen days later, Vivian’s body was found on a dirt road in Culiacán.
Her family members say they think a female acquaintance drugged Vivian and took her to the home of Vivian’s ex-boyfriend, who has been charged with her murder. Prosecutors say he struck her in the face with a beer mug and left her to bleed to death.
Her family says the authorities never investigated the woman as a possible accomplice, even though they told the police that the woman had returned Vivian’s freshly washed clothes to them days after she disappeared, claiming that Vivian had insisted on seeing her ex-boyfriend.
The attorney general’s office in Culiacán declined to comment.
Vivian’s sister, Alma Daniela, said that her sister had slowly transformed over the course of her relationship with her killer — a man who was also accused of murdering a woman in Las Vegas. Vivian became withdrawn, anxious and insecure about her appearance, undergoing cosmetic procedures, barely eating and living in constant fear.
“Her relationship with him changed her completely,” Alma Daniela said. “Things she once liked about herself and her body, she began to hate.”
In the bloody cartel war that has claimed more than 4,000 lives in Sinaloa, women have become strategic assets, and strategic targets.
Interviews with four members of the Sinaloa Cartel — three men and one woman — from the rival factions revealed some reasons behind the surge in killings and disappearances of women. Speaking on condition of anonymity because of the illegal nature of their activities, they described an organization consumed by suspicion as it faced an intensified government crackdown.
In that climate, they said, women have become targets because of what they know.
Their relationships with boyfriends, husbands, brothers, bosses and friends have long given them access to cartels’ most sensitive information: where senior operatives hide, which safe houses they use, where weapons and drugs are stored and how money is laundered, said one senior operative.
Now, the four operatives said, women in Sinaloa are increasingly abducted on suspicion of sharing that information with the authorities or rival factions. Others are targeted because they dated the wrong man, remained friends with the girlfriend of a trafficker under suspicion or even refused a cartel member’s romantic advances, the operatives said.
Earlier this year, Nemesio Oseguera Cervantes, the leader of a rival cartel called the Jalisco New Generation Cartel, was found after intelligence officials followed his lover to his hide-out. He was killed in a gunfight with Mexican security forces.
Before the cartel war, women largely laundered money, moved messages or guarded drugs and weapons. But as hundreds of gunmen have been killed or arrested, woman are now filling positions once reserved for men. They now organize kidnappings, oversee interrogations and sometimes carry out killings themselves, according to two cartel operatives, including a 40-year-old woman who distributes payroll to cartel operatives in Culiacán.
Rival factions also abduct, kill or disappear the wives, girlfriends, sisters and mothers of their enemies as retaliation or to send a message, the female operative said. Other women, she added, are killed simply because they saw or overheard something.
Before the war, the female operative said she had owned a nail salon. After violence destroyed her business, she began helping her partner transport drugs and weapons in the city, before joining the cartel full time.
“If you’re a woman driving with a child in the car, they won’t search you,” she said. “The police or the military just wave you through.”
The pervasiveness of cartel-related femicides in Sinaloa has also led some perpetrators to imitate cartel violence to mislead investigators.
Just before New Year’s Eve in 2024, Barbara Yáñez Uriarte and her 5-year-old son, Dante, were killed in their home. According to prosecutors, Dante’s estranged father came to the house and stabbed Barbara and Dante repeatedly, and then left their bodies beneath the Christmas tree and set the house on fire.
Barbara’s mother, Lucero Uriarte, said investigators had initially suspected criminal ties because setting the house ablaze was a common cartel tactic. The suspect remains in detention but has yet to face trial, according to court records.
“He killed my daughter; He killed my grandson,” Lucero said quietly, sitting in the charred living room. “And he killed me too. I’m already dead in life.”
