The Washington PostDemocracy Dies in Darkness

The 1989 search for missing American in Matamoros led to ‘slaughterhouse’

Updated March 9, 2023 at 1:47 p.m. EST|Published March 9, 2023 at 5:43 a.m. EST
Mark Kilroy, a 21-year-old University of Texas student who disappeared in Matamoros, was found dead in a mass grave in Mexico in April 1989. ((AP Photo/Houston Post))
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For nearly a month in 1989, family members and officials in Mexico and the United States frantically searched for Mark Kilroy.

The 21-year-old Texas college student had been seen last with friends during a spring break trip. They’d crossed the U.S.-Mexico border into Matamoros on March 14, 1989, to go bar hopping. Then Kilroy vanished without a trace — until his remains were found that April 11 on a ranch some 20 miles from the border city, along with those of 14 other people.

It wasn’t just an American’s mysterious death that brought an onslaught of global news crews to Matamoros. It was also the entanglement of a drug-smuggling satanic cult and its violent rituals that thrust the Mexican town into the spotlight.

Now, almost 34 years later, media outlets have again descended on Matamoros to cover the aftermath of a grisly scene: the violent kidnapping of a group of travelers from South Carolina. The four Americans, who’d crossed into Mexico last week so one of them could get a cosmetic procedure, were shot by a group of armed men on Friday. Two of them died. A fifth person, “an innocent Mexican citizen,” was also killed in the confrontation, the U.S. ambassador to Mexico said.

U.S., Mexico search for kidnappers after two Americans found dead

Video shows what happened after the Americans’ white minivan came under gunfire. Armed men, believed to be connected with the Gulf cartel dragged the four Americans into the back of a truck.

On Tuesday, officials announced that the two surviving victims had been moved to an American hospital. The incident, which authorities say might have been a case of mistaken identity, has sparked calls for accountability from both sides of the border.

What we know about Matamoros and the kidnapped Americans

In different decades and through varying circumstances, the two cases have brought international attention to Matamoros, a city where killings and disappearances are so common they rarely make headlines. The specter of drug-related violence has surrounded both kidnappings.

Some three weeks after Kilroy disappeared on March 14, 1989, Mexican police arrested a man on a marijuana charge. After that encounter, authorities searched his family’s ranch for more drugs but instead found what officials would later describe as a “human slaughterhouse,” the Los Angeles Times reported that year.

On April 11, officials uncovered a bloodstained altar fit with candles, animal skulls and human remains. The air smelled strongly of death. Among the dozen bodies was Kilroy’s dismembered corpse, The Washington Post reported in 1989. His legs were severed, and his spine had been removed. Human brains, hearts and blood were found in an iron cauldron — rituals of a cult that “believed human sacrifice ensured supernatural protection for their drug-smuggling operation,” according to local news reports.

The cult, dubbed Los Narcosatánicos, or the NarcoSatanists, operated on the family ranch, which they allegedly used as a base to smuggle approximately 1,000 pounds of marijuana a month to the United States, The Post reported.

Its leader was Adolfo de Jesús Constanzo, a Cuban American whom cult members referred to as “El Padrino” — the godfather. Constanzo “introduced various forms of mind control in the guise of religious mumbo jumbo. As Charles Manson had used the Beatles song ‘Helter Skelter,’ the Cuban used a movie called ‘The Believers,’ in which a father and his son are caught in a web of black magic,” Gary Cartwright wrote in the June 1989 edition of Texas Monthly.

Authorities suspected Constanzo killed Kilroy with a machete after torturing him. But he never faced a trial.

After an international manhunt to find the perpetrators behind the killings of at least 15 people discovered on the ranch, Constanzo and his followers fled to Mexico City, the New York Times reported. There, Constanzo allegedly ordered his own shooting in May 1989 — asking to be killed alongside his right-hand man. Police, who had been outside planning a raid on the apartment, found the men’s bodies peppered with gunshot wounds.

While Constanzo managed to evade the justice system, his followers did not. Mexican authorities’ investigation into the killings resulted in decades-long sentences for at least five narco-satánicos, according to the Associated Press.

Meanwhile, Kilroy’s parents, James and Helen, channeled their grief into creating a nonprofit to fight substance abuse in Kilroy’s name — a testament to the honor student who had hoped to become a doctor.

“We’re definitely putting our energy into the fight against drugs,” James told Rolling Stone months after his son’s death. “For that reason, we don’t look back. We try to look forward.”

Is it safe to travel to Mexico? What to know ahead of spring break.

Kilroy’s friends and family have for years warned Americans about safety when traveling to Mexico. After last week’s kidnappings, State Department officials raised the warning for travel to Matamoros to its most severe level, urging Americans not to visit the region.

Christina Hickson, whose son Zindell Brown was one of the Americans killed in Matamoros last week, told South Carolina TV station WPDE that if she had known the group was heading to the border city, “I would have never allowed them to get in that truck.”