In March 1989, twenty-one-year-old University of Texas student Mark Kilroy and some friends traveled south of the border to Matamoros, Mexico to celebrate the end of spring break, along with thousands of other American students that year. After drinking all night at a bar on the night of March 10, Kilroy got separated from his friends when they decided to call it a night a little after 2:00 am. No one would see Mark Kilroy alive again.

As one of several towns bordering the United States, Matamoros was popular with American tourists; however, by the late 1980s, it was beginning to develop a reputation for drug-related crime. In fact, Mark Kilroy was just one of sixty people who went missing in Matamoros in just the first three months of 1989 alone. When Kilroy’s friends reported him missing to the Brownsville, Texas police a massive search began, with investigators fearing Mark might have been kidnapped by one of the local gangs. It turned out, the truth was far worse than anyone had feared.

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Associated Press. 1989. "Leader in cult slayings ordered own death, two companions say." New York Times, May 8: 14.

Assocoated Press. 1989. "Hypnosis tried in hunt for student." Fot Worth Star-Telegram, March 17: 24.

Bragg, Roy. 1989. "Cult 'godfather' ordered killing." Houston Chronicle, April 13: 1.

—. 1989. "Fateful party is re-enacted." Houston Chronicle, March 25: 1.

Cartwright, Gary. 1989. "The Work of the Devil." Tecas Monthly, June 1.

Douglas, Jack, and Major Garrett. 1989. "13th victim pulled from killing field." Houston Post, April 14: 1.

Garcia, Guy. 1989. "The Believers: Cult Murders in Mexico." Rolling Stone, June 29.

Humes, Edward. 1991. Buried Secrets: A True Story of Serial Murder, Black Magic, and Drug-Running on the U.S. Border. New York, NY: Dutton.

Kreps, Mary Ann. 1989. "Machete blow reportedly killed Kilroy instantly." Houston Chronicle, April 12: 1.

Mishra, Upendra Nath. 1989. "Police search properties owned by alleged cult leader." United Press International, April 20.

Perez-Trevino, Emma. 2009. "Remebering Mark J. Kilroy." Brownsville Herald, March 8: 1.

Sanders, Kathy. 1989. "Rumors of Satanists kidnapping children have parents terrified." Fort Worth Star-Telegram, April 15: 1.

Schutze, Jim. 2023. Cauldron of Blood: The Matamoros Cult Killings. New York, NY: Open Road Media.

United Press International. 1989. "Parents of missing student seek help from state." United Press International, March 29.

Warren, Susan. 1989. "Kilroys say drug users 'to blame' for son's killing." Houston Chronicle, April 13: 1.

Cowritten by Alaina Urquhart, Ash Kelley & Dave White (Since 10/2022)

Produced & Edited by Mikie Sirois (Since 2023)

Research by Dave White (Since 10/2022), Alaina Urquhart & Ash Kelley

Listener Correspondence & Collaboration by Debra Lally

Listener Tale Video Edited by Aidan McElman (Since 6/2025)

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