
Volume 15 · Chapter 1
The Sacrificial Shack
Adolfo Constanzo, Serafín Hernández García, Elio Hernández Rivera
Victim: Mark Kilroy
Case at a glance
- When
- March 1989
- Where
- Matamoros and Rancho Santa Elena, Tamaulipas, Mexico
- Perpetrator
- Adolfo de Jesús Constanzo, with followers Serafín Hernández García and Elio Hernández Rivera
- Victim
- Mark Kilroy
- Outcome
- Constanzo died on May 6, 1989, during a police siege in Mexico City; Hernández García and Hernández Rivera were each sentenced in 1994 to 67 years
The case
Mark Kilroy was a 21-year-old pre-med student at the University of Texas at Austin. In March 1989 he and three friends went to South Padre Island for spring break, and like many students that week they crossed the border to spend an evening in Matamoros, Mexico.
In the early hours of March 14, Mark became separated from his friends and was forced into a vehicle. He was taken to Rancho Santa Elena, a ranch outside the city used by a drug-smuggling group led by Adolfo de Jesús Constanzo, who mixed Palo Mayombe ritual with trafficking and believed human sacrifice protected his operation. Held there through a day and a night of torture, Mark was then killed by Constanzo with a machete. On April 9, group member Serafín Hernández García drove through a federal police checkpoint, and officers followed the trail to the ranch. Two days later they began digging up bodies near a wooden shack, and Mark was among 15 victims found there.
Constanzo fled to Mexico City. On May 6, 1989, with police surrounding his hideout, he ordered follower Álvaro de León Valdez to shoot him and his companion, Martín Quintana Rodríguez, and both men died. In 1994 a Mexican court sentenced Elio Hernández Rivera, Serafín Hernández García and two other followers to 67 years each, and gave Sara Aldrete, whom prosecutors called the group’s priestess, 62 years.
Read the full story
This case is told in full in True Crime Case Histories, Volume 15 by Jason Neal.
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Where it happened
Why this case
“Mark was doing what thousands of college students did every spring, and a night across the border was part of the routine. That ordinariness is what I keep coming back to. The case broke because a smuggler ignored a checkpoint, not because of a clever lead, and readers should notice how close it came to going unsolved.”
— Jason Neal, author of True Crime Case Histories










