EXCLUSIVE: Dennis Rader, the BTK serial killer, says Oklahoma investigators have interviewed him a second time about a cold case kidnapping of a 16-year-old cheerleader named Cynthia Dawn Kinney.
Kinney, known to friends as Cyndi, was last seen June 23, 1976, in Osage, Oklahoma.
Her last known sighting came as she left a laundromat and entered a beige 1965 Plymouth with two women, according to the National Missing and Unidentified Persons System. She was 16 at the time.
Rader, 78, told Fox News Digital Wednesday investigators from the Osage County Sheriff's Office visited him for a second time about the case last week.
Cynthia Dawn Kinney was last seen June 23, 1976, in Osage, Oklahoma. Dennis Rader, also known as the serial killer BTK for his method of using "bind, torture, kill" on victims, was active about two hours away in Wichita at the time and says he has now been questioned twice in the case. (National Missing and Unidentified Person System, Jeff Tuttle-Pool/Getty Images)
"Sheriff from Oklahoma … is pursuing a case against me … regarding a missing girl on June 23, 1976," he told Fox News Digital. "Her name is Cynthia Dawn Kinney, presumed a kidnapped and missing case. I signed the Miranda on Friday. Yet to be arrested."
Osage County Sheriff Eddie Virden, however, said it was premature to talk about an arrest in the case.
"I can't tell you whether we're going to come up with anything or whether we’re not," he told Fox News Digital. "We won't leave anything uninvestigated."
It's unclear what brought his investigators to Rader's prison cell in Kansas. The sheriff said he could not discuss specific details of the open investigation.
Dennis Rader, pictured at right during his own trial, has been following current events from prison in Kansas. He has publicly weighed in on the Bryan Kohberger investigation. Kohberger, who like Rader majored in criminal justice, also studied under serial killer expert Katherine Ramsland, who has worked extensively with Rader over the years. (The Image Direct for Fox News Digital, Bo Rader-Pool/Getty Images)
But he said detectives were following up on all possible leads.
"We're investigating a cold case," he said. "We're doing our followups."
Kinney was 5 feet, 1 inch tall and 97 pounds when she vanished, according to authorities. She had brown eyes and brown hair.
She had worked at the laundromat, which her aunt and uncle owned at the time, according to The Charley Project, which compiles and republishes information on missing person cases. Possible sightings were reported in Kansas, according to the outlet, but she was never found.
"We hope we come up with something for closure and justice for victims," Virden said. "But an investigation is an investigation; sometimes they go places.
"There may be some things that we felt like we need to look into, and we're following up on those."
Rader told TMZ in February he had been visited by Osage investigators for the first time, claiming investigators may have been exploring a potential connection because he had been active about two hours away in Wichita, Kansas, at the time. He denied any involvement in Kinney's disappearance.
Cynthia Dawn Kinney in a black-and-white photo from 1976. She was last seen wearing blue jeans and a peach blouse leaving the Osage Laundromat and entering a beige Plymouth with two women in 1976. (National Missing and Unidentified Persons System)
He is serving multiple life sentences in the El Dorado Correction Facility in Kansas for 10 brutal murders committed between 1974 and 1991.
Rader's daughter, Kerri Rawson, told Fox News Digital she does not believe the Kinney case fits the distinct patterns of her father's other murders, which involved stalking his victims, home invasion attacks and taking "trophies." And she said she has no knowledge of him having reason to be in Oklahoma in June 1976.
"While it is my hope and prayer this missing person cold case gets solved for the family and friends of Kinney, in no way do I believe my father is connected. And, in fact, I believe he’s telling the truth on this, as he has done since 2005 on the 10 he did commit," she said.
Rader said he has been following current events and high-profile crime stories from prison, including the Alex Murdaugh murder trial and the University of Idaho student stabbings and the arrest of suspect Bryan Kohberger.
Kohberger, like Rader, studied criminal justice. As part of his master's degree in the field from DeSales University, he took classes under Dr. Katherine Ramsland, an expert on serial killers who has worked extensively with Rader.
"It appears to me serial killers and others follow criminal justice like some people follow sports and political issues," Rader told Fox News Digital. "There may be a fine line between [criminal justice] and extreme bad behavior. Someone ought to do a book on that."