Nearly 30 years after the death of her 3-year-old daughter, a mother has been arrested in Mexico by U.S. law enforcement officers on first-degree murder charges.

Anna Marlene Somoza, 60, was arrested by the U.S. Marshals Service after more than 12 years as a fugitive in Mexico. Her close connections to cartels allowed her to avoid apprehension, authorities said.

Somoza will be extradited to the United States to face charges for allegedly murdering her daughter, Crystal Reyes, according to the U.S. Marshals Service. Before her death, Reyes was subjected to severe abuse, torture and starvation, the agency said.

Confined to a small dog kennel, Reyes was bound by her hands and feet, gagged and left for weeks at a time. On Jan. 30, 1997, Reyes was bound, suffocated with a towel taped to her face, and left to die inside a sealed cardboard box, the agency said.

Authorities began investigating after human bone fragments were found in a deserted area of Arizona by a hunter in November 1998. Almost two decades passed.

Then in August 2014, forensic DNA analysis identified the fragments of bone as remains of Reyes.

Detectives interviewed the child’s biological father and confirmed her identity using his DNA. Then, they said, they had sufficient grounds to charge Somoza and Avelino Tamala, her boyfriend at the time of Reyes’ death, with first-degree murder in December 2014. Tamala was found guilty of Crystal’s murder in 2016. He was sentenced to life in prison. But Somoza had been deported years earlier.

Somoza had an extensive criminal history before being charged in her daughter’s death. She had been connected to a major transnational drug trafficking network active along the southern Arizona border throughout the 1980s and 1990s.

After her 1993 arrest for the sale and transportation of marijuana, she agreed to act as a confidential informant for an Arizona law enforcement agency.

Through that, she met Tamala, a narcotics detective, and began "an improper romantic relationship," according to the U.S. Marshals Service.

Not long after Reyes’ birth in Mexico in 1993, the mother and daughter began living with Tamala in Arizona, according to the agency. Tamala was not the father of Reyes.

The abuse Reyes endured likely wasn’t caught because she wasn’t attending school, said Stacy Vaughan, vice president of growth and prevention at Childhelp, a child abuse prevention organization.

"The majority of reports come from the education system in our country, from teachers, counselors, schools," Vaughan told Fox News Digital. But a case like this may be prevented with the modern legislation in the United States, she said.

"In the past 20 years, many states have passed laws not only mandating that professionals report any suspected abuse, but…every adult over the age of 18 is considered a mandated reporter." In 1999, the year after Reyes’ remains were found, Somoza and Tamala were arrested on drug- and weapon-related charges. Somoza served eight years in federal prison and was deported in 2008.

After the child’s remains were connected to her as the mother in 2014, investigators from five state and federal agencies began to search for her.

She’d "taken deliberate and extensive measures to evade detection by law enforcement while remaining at large," according to a statement from the U.S. Marshals Service.

In October 2022, authorities obtained an arrest warrant that would allow them to extradite her back to the United States. But they still needed to find her.

In 2026, the search for Somoza was designated a major case, "dedicating additional manpower and resources to the investigation," according to the U.S. Marshals Service.

In early September, the agency learned that Somoza was "actively evading detection" in Cuernavaca, Mexico, the agency said. On Oct. 18, Mexican law enforcement officers caught her in Xochitepec, Mexico. The U.S. Marshals Service now will work with the Mexican government to extradite Somoza to the United States, Russell Lorfing, a former federal prosecutor, told Fox News Digital.

They have "diplomatic assurances," Lorfing said. "But she will physically be handed over, and U.S. marshals will have to fly to Mexico. Or they'll arrange a coordinated kind of border handover." The extradition process usually takes 14 days when it’s within the United States, Lorfing said. But international operations can take months. And they can stretch into years, if the defendant challenges the charges. Somoza "has a right to challenge it under the federal system," he said.

That's done through an amparo, an appeal that challenges her fundamental constitutional rights. "These amparos are a big deal in Mexico," he said.

"It hits the pause button, too. So a three-month extradition can turn into a two-year extradition."