The woman called the "godmother" of a drug-smuggling cult that killed 15 people along the U.S. border has confessed to taking part in ritual slayings, U.S. and Mexican authorities say.

Sara Aldrete Villarreal, 24, and two other alleged cult members were charged Wednesday in the weekend deaths of their leader and his right-hand man, authorities said. Police say the two had ordered their own deaths.A source in the Mexico City attorney general's office said Aldrete has a split personality, and U.S. Customs Agent Oran Neck told a news conference that she "confessed to conspiracy and involvement" in ritual killings.

The three were not charged in those killings.

Neck returned to Brownsville, Texas, on Wednesday from a 72-hour trip to Mexico City after assisting Mexican authorities in the case.

Aldrete, a Mexican who attended college in Texas, was wanted on both sides of the border after police, acting on a tip, dug up 15 mutilated bodies at a desolate ranch near the border town of Matamoros on April 11.

Cult members boiled brains and other human organs as part of their belief that human sacrifice would give them occult protection when they smuggled marijuana into the United States, authorities have said.

One body was identified as that of Mark Kilroy, 21, of Santa Fe, Texas, a student at the University of Texas.

Aldrete told reporters at two news conferences earlier this week that she knew nothing about the killings.

"She's giving a lot of data with great detail to investigators working this case right now," Neck said.

The source in the attorney general's office, speaking on condition of anonymity, said that when Aldrete talks to police about cult rituals she loses that "charming aspect" she exhibits when she faces television cameras.

"I would say she has three personalities," he said.

One personality comes out when she faces the cameras and denies any involvement in the human slayings, another emerges when she talks to police and "the third one comes out when she talks to herself," the source said.