Samantha Spiegel, 19, says while engaged to John Mark Karr he tried to get her to recruit girls ages 4 to 8 into a sex cult, NBC reported Wednesday.
"His mission is to create a cult that he wants to call 'The Immaculates,'" Spiegel said, "of little girls that would have sexual relationships with him and do whatever he wanted and just, like, be his little minions."
Police in California and Washington say they want to talk to him but can't find him, NBC said.
Karr is reportedly living as a woman under the name Alexis Valoran Reich, with a group of "minions" who help him hide and provide him with food and money.
In 2006 Karr confessed to the sensational 1996 murder of 6-year-old beauty contestant JonBenet Ramsey in Colorado.
Police rejected Karr's confession when his DNA did not match a sample from the Colorado crime scene.
Authorities dismissed him as "a kook hungry for attention," NBC said.