One of the women depicted in drawings done by the self-proclaimed BTK serial killer, Dennis Rader, has possibly been identified, according to a sheriff in Oklahoma.
Osage County Sheriff Eddie Virden would not disclose further details on the possible ID of the woman, who was depicted in one drawing as wearing green and being bound in a barn.
He said his team is poring through "very, very good tips," from the public regarding possible additional victims following CNN's exclusive reporting on Rader's detailed colored drawings of barns with female victims, which were first recovered by law enforcement after his arrest in 2005.
"It's going to be a busy week," Virden added, saying the tips so far have "provided more information."
With the help of experts, Virden's team believes a few rare color images among hundreds of sketches in Rader's belongings may depict more crimes he committed not only in Oklahoma, but also Kansas and Missouri.
"We have a lot of follow ups to do, of course, a lot of interviews to do," Virden said. "Barn-wise we've got a lot of things sent to us for us to check out."
Rader pleaded guilty to 10 murders that took place from the 1970s to the 1990s in Wichita, Kansas, for which he's serving 10 consecutive life sentences in a state prison.
He suggested in a letter found long before his capture that he should be called "BTK," short for "bind, torture, kill."
In recent prison interviews, Rader told Virden and other local authorities he did not commit any other murders. Rader's public defender told CNN he has no comment at this time.
Investigators hope that in releasing Rader's drawings, "someone might recognize one of these barns or the unique features in them, or the closeness of the silo to the barn, or possibly might have even found items that they didn't know why were there that could be very important in this case," Virden told CNN.
Law enforcement recently intercepted communications from Rader in prison revealing there might still be some hidden items in old barns, according to the sheriff.
Rader's daughter, Kerri Rawson, said on "CNN This Morning" that authorities believe they had identified the "young woman in the green shirt" in her father's drawings but could not disclose further, citing the open and active case.
Rawson has been volunteering with investigators, walking old haunts and recalling childhood memories that may be significant, she said. And she confronted her father for the first time in 18 years, visiting him in prison twice in recent months.
Rawson also told CNN she agrees with her father recently comparing himself to Rex Heuermann, who has been charged with the murders of three women found on New York's Long Island.
"There are similarities. They both were the same age... They were both arrested at 59. They both had a wife. They both had two children," Rawson said.
"We are still waiting to find out a lot more on Heuermann. Now we are finding out a lot more on dad. It's just an ongoing process to see where we're going to land on both of them," she said. "It's going to be a long-term event for both cases and both families and the victim families, unfortunately."
A possible connection to missing persons case
In January, the sheriff's office launched an investigation, poring over Rader's writings, sketches and other evidence they obtained from Wichita police, finding what they believe are potential connections to several unsolved cases in the area.
Authorities have said they believe the killer may have buried 16-year-old Cynthia Dawn Kinney -- last seen at a laundromat in Oklahoma in 1976 -- in a barn near the Kansas-Oklahoma border.
Months after Cynthia disappeared, the Osage County Sheriff's Office documented an anonymous call from a man claiming the teen's body could be found in an old barn along the Oklahoma-Kansas border, Virden told CNN.
Although investigators recently were able to track down the deputy who took the call, the barn is still a mystery.
Rader is known for his cat-and-mouse games, sending clues about his murders to law enforcement in the years before he was eventually arrested.
Virden's team believes a barn closely positioned next to a silo was likely a favored haunt of Rader's.
Rader often sketched, according to Rawson. He honed the skills in a college drafting class, she told CNN.
"My father did drafting at our house, he drew up plans for the gardens," Rawson said. "And my dad needed to always be outside and be in the air and winter was hard for him. And so we had to find things for him to do because when he got inside and he was too cooped up, he would get all angry."
And he loved barns and silos.
"My father absolutely loves barns and silos. Every time we drove around going camping, fishing, to college, he'd absolutely say this one -- like he said, I want to retire here. And he would tease my mom about it," Rawson said. "And then after he was arrested, we found out later that he had massive fantasies about those specific locations. So now we're driving around trying to find those by my memory and noting them because we need to go see, is there anybody missing or buried there."
A fascination with barns
Rader's disturbing sketches show three bound women in what investigators believe to be barns.
One drawing shows what looks like a young female gagged and bound at her arms and legs. Officials point to the black piping running through the barn walls.
"The reason you would have that is if you were moving livestock through there, that those bars would keep the livestock from hitting probably the tin or the wood on the outside of the barn so that if an animal hit it, you know, they wouldn't go through and dent up the tin or knock the wood off the outside," Virden, the sheriff, told CNN.
Osage County investigators believe the sketch could be linked to a missing woman last seen in Southeast Kansas in 1991.
"We know from things Dennis said on this exact photograph that it was a drawing he created from an actual barn," Virden said.
Another color drawing depicts a female victim bound and gagged in a red top.
"That would be a barn that had wood slats. You know, possibly a rounded post but in that area of the barn what would have possibly a wooden floor, you know and a lot of times in tack rooms inside of barns or in feed rooms or storage. They wouldn't leave a dirt floor because they didn't have livestock in that area."
A third drawing Rader penned in black ink shows an angle glaring down at a female lying in a barn loft space bound by the neck to a staircase post. The staircase construction caught the attention of law enforcement.
"The support post appears to have a bracket and then a bolt that bolts through that to hold everything together," Virden said.
Newly discovered evidence
Last month, Virden's team uncovered what Rader called a "hidey hole" containing new evidence not previously discovered by law enforcement on the lot that was once his family home. Bondage materials were among the recovered items.
City officials demolished the home in Park City, Kansas, in the years after his arrest, but the reinforced hole, according to Virden, remained intact nearly 2 feet in the ground.
Rader himself led the investigators back to the scene: Virden's team uncovered a letter he wrote in 2008 from prison describing items he hid under the floor of a shed behind his home.
Now, Osage County investigators hope state and federal agencies will intervene to help process the evidence that could still contain DNA to connect the serial killer to the unsolved cases or rule him out as a suspect.
They also hope to test "trophies" recovered in 2005, matching the description of items last seen with the victims in the unsolved cases.
A spokesperson for the FBI's Kansas City field office said they were unaware of the bureau actively assisting in any current BTK-related investigations.
The Kansas Bureau of Investigations has met with Osage County authorities but has not assisted in any property searches, according to Melissa Underwood, the agency's communications director.
Rader, 78, is incarcerated at the El Dorado Correctional Facility in Kansas.