Mark Kilroy, a teenage boy from Chicago who was kidnapped in 1989 over spring break in Matamoros by a satanic cult. | Courtesy of Brownsville Herald

Picture this: It’s 1989. Big crowds by the beach, parties all day, and festivals at night—that’s the thrilling sound of Spring Break. What people don’t talk about, though, are the dangers that come with too much booze and strangers all around. Mark Kilroy was a college student at the University of Texas at Austin who went to Matamoros, Mexico for Spring Break with his friends. Mark was kidnapped by men in a red truck and held at gunpoint, while his friends used the bathroom in an alley right before they were to cross back across the border of Mexico to South Padre Island. Mark’s friends thought that he had gone off with a girl somewhere, but the next morning, he wasn’t to be found. Adolfo de Jesús Constanzo, the leader of a satanic cult, had wanted someone selected at random, preferably a white man, for his next murder. Adolfo de Jesús Constanzo, a man on the hunt, wanted to kill someone, and he was successful. And after Mark Kilroy had been missing for a long time, the police decided to step in and look for him. Although they were not able to save Kilroy from death, they did find Adolfo and the members of his cult, to bring them to justice.

Spring Break for Mark Kilroy lived up to the hype, but little did he know, his Spring Break would include being taken by a twisted cult in need of human sacrifice. Constanzo, the cult leader, ordered his members to find a man, and this time, Mark was the unfortunate victim. Constanzo just felt like killing someone.1

Multiple graves that held the bodies of ritually sacrificed murder victims in Matamoros, Mexico from a cult. Twelve bodies were found here at this place, including the body of Mark Kilroy, a missing college student all under ground and in small pieces | Courtesy of Murderpedia

Mark Kilroy was just a teenage boy, who wanted to have fun with his friends over Spring Break. When they took a detour to Matamoros, Mexico before they headed home that night, they stopped by a bar. They were able to go to clubs and bars, because it was legal to drink at 18 in Mexico. It was outside of this bar that the crime was committed, and Mark wasn’t seen again. Before the Kilroy incident, it was unknown to the valley police that they had a group of “narcosatanicos,” or satanic drug dealers, among them. This group was led by Adolfo de Jesus Constanzo, and its members were drug traffickers and murderers. In Constanzo’s early life, he was baptized Catholic, and had even been an alter boy. He was born in Miami, Florida, but moved to Mexico shortly after his mother got remarried. Later, his father had passed away and he started to study a religion called “Palo Mayombe,” which was the study of animal sacrifices. His mother would partake in committing petty crimes with Constanzo, like shoplifting and a little vandalism. He then moved to Mexico and became friends with the people who eventually became followers in his cult. After that, he fell into the bad life of murderers with these members. Adolfo and his members would cast spells and use animals like chickens, goats, and snakes to perform their sacrifices. They would also get human bones from graveyards and mix them into a cauldron. This large witch-like pot was the “prized possession” of their cult. Constanzo believed that the cauldron brought power and protection when certain contents were mixed into it. In his case, the “contents” included human body parts and blood. The cult believed that the more they would kill and do terrible things, the more powerful the protection would be for them. The cult members gave him the nickname of “godfather” (El Padrino). On one night during that Spring Break in Matamoros, Constanzo felt the need to feed the cauldron, and for this, he needed a human corpse. Constanzo gathered a few of his members, including “godmother” (La Madrina) Sara Maria Aldrete, who was made high priestess of the cult and second-in-command, and sent them all to commit the crime. Coincidentally, they pulled up to the same bar that Kilroy stood outside of alone, where they took him as their human sacrifice.2

All of this information about Constanzo and his cult was unknown to the police before the disappearance of Mark Kilroy. Earlier that night, Mark and his friends were in the bar until about two in the morning. Right before leaving to go back to South Padre, Mark found himself alone outside of the bar waiting as his friends, who were drunkenly urinating in an alley nearby. This is when the Narcosatanico members took action. By the time Mark’s friends came back to look for him, he was gone. His uncle, Ken Kilroy, happened to work at the United States Customs Service. Because of Ken, the case was brought to the police’s attention quickly, and soon the low-key satanic cult was exposed. Investigators found a shack on Rancho Santa Elena, and they discovered the cauldron that seemed to be holding blood, a brain, and other human organs. That same day, fifteen torn-up bodies were also identified, including Kilroy’s. He was one of the very few random victims, as most of them had been targeted for being drug dealers, whereas he had been just an innocent man outside of a bar. They said that by doing this, they got some type of justice with the devil and protection. They felt that they needed to do this, and they found some type of comfort in doing such a cruel thing to these innocent people.3

Adolfo de Jesús Constanzo (The Godfather) was the leader of a satanic cult in Matamoros, Mexico, serial killer, and a drug dealer | Courtesy of Alchetron

After the police were alarmed and the cult had been found out, the members split apart and fled Mexico as soon as their crimes hit the news. Shortly after, the members, Constanzo, Quintana, and De Leon, were found in a house and cornered by the police, and were immediately arrested. After trying to find other ways to escape, they figured that it was going to be impossible, so De Leon was ordered by Constanzo to shoot him and Quintana so they could have an easy way out rather than go to prison for the rest of their lives. Constanzo was then murdered, along with Quintana, two of the many members responsible for the death of Kilroy. The police walked in to find De Leon, and took him in for thirty years in prison for the murder of Kilroy, as well as for the murders Constanzo and Quintana. Soon all other members were caught and locked up with the exception of two, who were still wanted for Kilroy’s murder, but were unable to be found at the time. 4

As the police were searching the Rancho Santa Elena, they found this “cauldron” that had blood, animal parts, and Mark Kilroy’s brain. They would do this to torture people | Courtesy of PA Photos

When the police notified Kilroy’s parents, they were devastated and sad because their son was just starting his life. He was a premed student and all he was doing was standing outside of a bar waiting for some friends. The cult had no reason for their kidnapping and murder. They spent many days looking for him only to be found brutally murdered and his body in bits and pieces with animal remains, and for no reason. They weren’t seeking revenge, and all his parents wanted was to have his body for proper burial with his friends and family. The police started to search for Mark for the burial and all they had found was his body in bits and pieces, not able to be taken back to his family. When the police broke the news, Mark Kilroy’s parents reached out for support and found comfort in the Christian community. They grew closer to God and found some type of peace, but they were still very devastated at this and did not quite understand why this happened to their son. The arrests of the members involved put Kilroy’s parents in a state of ease, but nothing made up for the murder of Mark Kilroy as well as for the families of the other murder victims.5

  1. Matt Davis, “Voodoo cult raided by police after more than 60 people disappeared,” Life! Death! Prizes! (website), June 19, 2017, https://www.lifedeathprizes.com/real-life-crime/adolfo-de-jesus-constanzo-killer-who-sacrificed-people-24129.
  2. Emma Perez-Trevino, “Remembering Mark J. Kilroy,”  Brownsville Herald, & Brownsville Herald (website), https://www.brownsvilleherald.com/news/local/remembering-mark-j-kilroy/article_dfad19e2-ad2b-51a9-8f49-a3a38dd7939f.html.
  3. “Friends Remember Spring Break Murder of Mark Kilroy in 1989,” ABC13 Houston (website), March 20, 2016. https://abc13.com/news/friends-remember-murder-of-mark-kilroy-in-1989/1253858/.
  4. “Leader in Cult Slayings Ordered Own Death, Two Companions Say,” The New York Times, May 8, 1989. https://www.nytimes.com/1989/05/08/us/leader-in-cult-slayings-ordered-own-death-two-companions-say.html.
  5. Guy Garcia, “The Believers: Cult Murders in Mexico,” Rolling Stone (website), June 25, 2018, https://www.rollingstone.com/culture/culture-features/the-believers-cult-murders-in-mexico-53577/.

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36 Responses

  1. This story is so sad and bizarre, and also incredibly interesting. I had never heard of this cult until now, and it’s even more bizarre hearing that Adolfo was so involved in the Catholic Church, yet decided that doing evil works was his way of life. I found it so disrespectful how his group took bones from the graveyard for their cauldron. Even more upsetting next to killing an innocent boy is how Adolfo took the easy way out.

  2. What happened to Mark Kilroy was devastating to read about, he was just a young man trying to enjoy spring break. This is a prime example of being at the wrong place at the wrong time. I had never heard about this satanic cult before led by Adolfo De Jesus Constanzo, it is a real tragic that they sacrificed Marks life. My condolences to his family for having to have faced this terrifying situation.

  3. Hey Briana, your article was so interesting to me because I had never heard about Adolfo De Jesus Constanzo and his Cult before. What happened to Mark Kilroy that night is such a tragedy, he was an innocent man and he had so much ahead of him. What people can learn from this story is to always watch your surroundings and try to never stay by yourself in a place you’re not familiar with.

  4. This was a really interesting article; very unsettling and sad. I can’t believe that the valley was involved in an investigation of a Satanic cult and it just isn’t something that people talk about. I can’t imagine what his friends were thinking when they couldn’t find Mark or his parents when they heard the news. I hope they all found some closure.

  5. Great article Briana! What a tragic story to hear, but I am glad to see that his murders were arrested, and received punishment for their heinous crime. I had never heard of Marc Kilroy or this satanic cult, but after reading this article I will never forget them.

    I do have a few questions though. First, how long was this cult around before the murder of Kilroy? And secondly, how many people were murdered before all the members either died or were arrested?\

    Great article!

  6. As soon as I read the title of this article I just knew I had to read it. After reading this, I am scared because I had no idea, satanic drug dealers, were a thing as if being a drug dealer was not bad enough alone. They also had to be satanic and make human sacrifices. It is so sad that he had to end up being the victim, I hope he didn’t suffer too much…RIP

  7. I didn’t know of this cult nor did I know about this case prior to reading this article however I found it to be interesting. It’s interesting how Adolfo turned nothing into something with his cult and how he managed to get individuals to actually follow him and partake in such activities. It’s also very saddening to see that there was no motive for Marks’ murder other than it was just for the sake of a satanic ritual.

  8. This is such a sad and very disturbing story. I am from Mexico and I had never heard about this, and it is absolutely disgusting. It is very sad that this happened, but unlike many other deaths, I am glad that this one was solved and that there was a clear end to it. Although it must be very confusing and devastating for the family, at least they got some sort of closure, and the story shows how crazy people can be and how you should always be careful.

  9. This article was so interesting and scary. I cannot imagine how scared that boy must’ve been. It’s crazy to think about how an innocent trip could take a horrifying turn. I had never heard about this story before, but it’s very dark and sad. Another interesting part of this article was how Constanzo grew up in a nice environment but eventually went down a dark path.

  10. This was a very interesting article! It made me realize that anything can happen to anyone especially to a man since only cases of woman being kidnapped are more frequently shown. Also its very sad that such a young man, ready to do something big , was killed on spring break. Just knowing that he was waiting for his buddies and not joining them would mean his life being taken away. Another thing that I found interesting in this article is when it was describing why they killed people and what it meant for the people in the cult.

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