BROWNSVILLE, TEX., APRIL 15 -- A bizarre sect of suspected drug smugglers was influenced by a movie called "The Believers" about the time they began performing human sacrifices to protect their illegal business, police said today. The 1986 movie, starring Martin Sheen and directed by John Schlesinger, is about rich, influential families who protect their prominence with rites including human sacrifice. The motives of the movie's characters are similar to those of the members of the cult accused of killing at least 13 people on a ranch west of Matamoros, Mexico, police said. "They keep bringing the movie up," Cameron County Sheriff's Lt. George Gavito said after interviewing two suspects. "They talk about it like that had something to do with changing them." Thirteen bodies were found this week on a ranch 20 miles west of Matamoros, across the Rio Grande from Brownsville. Police said most of the cult's victims died either from blows dealt with a machete or a hammer. Some of the victims were mutilated, and their brains, hearts and other organs were removed and boiled with blood in what suspects have described as sacrificial rites to seek magical protection for their drug smuggling, police said. Authorities said the gang smuggled a ton of marijuana a week into the United States. Four suspects are in custody in Matamoros. Four others -- including a man and woman whom sect members called "the godfather" and "the godmother" -- are at large. U.S. federal authorities videotaped interviews Friday with two of the suspects in custody in Matamoros, said Oran Neck, agent in charge of U.S. Customs in Brownsville. Serafin Hernandez Garcia and Elio Hernandez Rivera told the U.S. officials the cult's "godmother," Sara Maria Aldrete, recruited them into the group early 1988, Neck said. Aldrete, 24, and the cult's Cuban-born leader, Adolfo de Jesus Constanzo, 26, at first practiced a widespread Afro-Cuban religion called Santeria, or "the way of the saints," the suspects told authorities. Santeria assigns Roman Catholic saints the characteristics of West African deities. Like many religions originating among poor, farming people, Santeria sometimes calls for the sacrifice of animals, but never humans. The smuggling group's rites turned sinister late last summer, about the time Aldrete began urging members to watch videotapes of "The Believers," Gavito said. The movie did not in itself incite group members to perform human sacrifice, Gavito said, but it reinforced their desire to begin killing people in an attempt to provide a magical shield for their alleged drug activities.