Case 123

Mark Kilroy

*** Content Warning: extreme violence, sexual assault, animal cruelty ***

When 21-year-old Mark Kilroy and a group of his friends headed to South Padre Island in Texas for Spring Break, all they had in mind was sun, sand and celebration. However, when they crossed the border into the Mexican city of Matamoros to party with their fellow college students, things soon took a dark turn. 

Mark Kilroy became separated from his friends and couldn’t be found. A large scale search commenced in both Mexico and the United States as authorities feared Mark had fallen victim to a drug-related robbery. What followed was an international manhunt that took detectives into the grisly world of Palo Mayombe rituals, sinister cult practices and human sacrifice. 



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Research – Erin Munro 

Writing – Elsha McGill and Milly Raso

Creative direction – Milly Raso

Narration – Anonymous Host



‘Flatline intro’ and ‘Come play with me’ intro and outro –

Audio production – Mike Migas 

Scoring – Mike Migas and Andrew Joslyn



Logo and website design – Paulina Szymanska



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Passport to Murder: Mark Kilroy

Deadly Cults, season 1, episode 4: Palo Mayombe 





The Believers: Cult murders in Mexico – Rolling Stone, June 29, 1989

The Work of the Devil – Texas Monthly, June 1989

Spring Breaker vanishes – The Monitor, March 17, 1989

UT student disappears in Mexico – Austin American-Statesman, March 17, 1989

Father joins in search for missing UT student – Austin American-Statesman, March 18, 1989

Reward tripled for student – Austin American-Statesman, March 22, 1989

Re-creation of UT student’s disappearance airs tonight – Austin American-Statesman, March 26, 1989

Show on missing UT student spurs calls – The Monitor, March 27, 1989

Show sparks 1,300 phone calls about Kilroy case – The Galveston Daily News, March 28, 1989

Victim mourned in home town – The Monitor, April 12, 1989

Cult slaying uncovered in Matamoros mass grave – The Marshall News Messenger, April 12, 1989

Friends end weeks of waiting – Austin American-Statesman, April 12, 1989

Family, friends mourn SF man – The Galveston Daily News, April 12, 1989

Family of cult victim praying for suspects – The Victoria Advocate, April 13, 1989

Ringleader sought in satanic killings – Chicago Tribune, April 13, 1989

Five arrested for trying to dupe Kilroys – The Galveston Daily News, April 28, 1989

Kilroy’s mother asks for prayers for murderers – The Galveston Daily News, April 14, 1989

More than 1,000 attend funeral Mass for Kilroy – The Galveston Daily News, April 16, 1989

Cult victim’s funeral held – The Victoria Advocate, April 16 1989

Suspect digs up body of 13th victim – The Galveston Daily News, April 14 1989.

2 bodies unearthed at Mexican Farm – Austin American-Statesman, April 17 1989.

Cult leader ordered his own death – Austin American-Statesman, May 8 1989

Mexico massacre: Potent mix of ritual and charisma – Los Angeles Times, May 16 1989

Satanic cult leader orders follower to kill him – The Kerrville Times, May 8 1989

Cult ‘godmother’ says she was held hostage – The Paris News, May 9 1989

Drug awareness comes out of son’s slaying – El Paso Times, March 8 1990

Spring breakers urged to be careful – The Monitor, March 8 1990

Breakers invade Padre Island – The Monitor, March 7 1990

5 sentenced for ritual slayings – Austin American-Statesman, May 4 1994

Cult members get long prison terms – The Odessa American, May 4 1994

Mexico reduces cultists’ jail time – The Brownsville Herald, March 26 1998

Judge lowers sentences in Kilroy cult murders – The Monitor, March 26 1998

U.S. Attorneys Office abruptly halted prosecutions in 1993 – The Brownsville Herald, March 7 2009

Rumors about cult frighten parents – The Galveston Daily News, April 25 1989

Parents of slain Texan keep up war on drugs – New York Times, July 17 1989

20 years after son’s death, Santa Fe couple runs foundation in his honor – Houston Chronicle, March 24 2009

Kilroy family carries on without Mark – The Brownsville Herald, March 7 2009

Kilroys thank Valley, Matamoros for their help – The Brownsville Herald, March 7 2009

Remembering Mark J. Kilroy – The Brownsville Herald, March 7 2009

Nature reclaiming death ranch a year after bodies found – AP News, April 11 1990

Helen Kilroy obituary – Galveston County The Daily News, January 1 2015




Crime Library – Adolfo Constanzo

Murder of Mark Kilroy – Wikipedia

Mark Kilroy Foundation 

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