Sara María Aldrete Villareal (born September 6, 1964) is a Mexican serial killer who was convicted of murder while heading a drug-smuggling and human sacrifice cult with Adolfo Constanzo.

The members of the cult, dubbed by the media as The Narcosatanists (Spanish: "Los Narcosatánicos"), called her The Godmother ("La Madrina"), with Constanzo as "The Godfather" ("El Padrino").

[1] Adolfo Constanzo, a Cuban American serial killer and religious cult leader, introduced her to witchcraft and dark magic.

He gave her the nickname "La Madrina", Spanish for "godmother", and initiated her into his cult, which was a conglomeration of Santería, Aztec warrior ritual, and Palo Mayombe, complete with blood sacrifices.

In 1989, the killings grew more frequent and gained attention when American tourist Mark J. Kilroy, a University of Texas student on Spring Break, was abducted.