Ritualistic torture and human sacrifices are the things nightmares are made of, which is what one terrifying cult was all about.
The group was called "Los Narcosatánicos," which, translated into English, means The Narco-Satanists.
Led by cult leader Adolfo Constanzo and his "witch," Sara Aldrete, they are responsible for at least 15 murders.
Constanzo was born in Miami, Florida, in 1962. His family immigrated from Cuba, and both his mother and grandmother were "Santeras," or priestesses in the Santeria religion.
This syncretic religion blends Christianity with religions brought from West Africa to the Caribbean, such as Haitian Voodoo. According to the BBC, ritualistic sacrifices of things like chickens are common in this religion. He was raised practicing witchcraft, and it only escalated as he got older.
Constanzo moved to Mexico City in 1984 and offered spiritual cleansings and magic spells to the city's elite, including members of drug cartels.
He had male and female lovers he began recruiting into his cult, and members called him "El Padrino," which means The Godfather. One of his followers was Sara Aldrete, who would become his second in command and was known as "La Madrina," The Godmother.
Constanzo and his followers moved their operation to property owned by the Hernande cartel family in Matamoros and less than a mile from the border of the USA.
Soon he was demanding his followers sacrifice human victims to the gods, believing these acts would impose supernatural powers on them and their associates. Their first victims were members of other gangs and corrupt cops, who were tortured and ritualistically killed.
They boiled body parts into a stew that they drank, believing it made them invincible.
In March 1989, Constanzo demanded an "Anglo male" for his next human sacrifice, according to Salt Lake City's Deseret News.
Unfortunately, 21-year-old Mark James Kilroy of Santa Fe, Texas, fit that order. He attended the University of Texas in Austin, studying to become a doctor.
Kilroy and three friends traveled to South Padre Island, Texas, for spring break. Cult members abducted Kilroy when he was barhopping and took him back to the ranch, where Costanzo killed him.
Kilroy's uncle was a special agent with the U.S. Customs Service, and officials from both countries started a detailed investigation within days of his disappearance.
One cult member who believed he was invincible drove through a roadblock on April 1, 1989, leading police directly to the ranch.
Authorities immediately found 65 pounds of marijuana and a ritual shed. Eventually, 15 bodies were exhumed from the site, including that of Kilroy. Victims had either been burned, shot, or hacked to death with a machete. Many were missing body parts, like legs, hearts, ears, or eyes. Kilroy's brain was found boiled in a pot inside a shed.
Several cult members were arrested and confessed to several murders within two weeks.
Mexican police eventually tracked Constanzo to an apartment building in Mexico City. He picked up a machine gun and began firing when he saw them outside.
Constanzo ordered one of the cult members to kill him rather than let him be arrested, and the cult member did as he was told.
Aldrete was arrested as she tried to flee the apartment. According to the Associated Press, she was sentenced to 62 years in prison, and several of the other prominent cult members were also sentenced to lengthy prison sentences.
