PARK CITY, Kan. – FIRST ON FOX: Authorities looking into cold case murders and unsolved disappearances have uncovered "items of interest" in a new search conducted over the past two days at the former Park City, Kansas home of Dennis Rader, the BTK serial killer.
"The short version is, through the investigation, we developed information of some possible trophies of Dennis Rader's, and we followed up on those leads and worked with Park City," Osage County Sheriff Eddie Virden told Fox News Digital. "Did a dig in the area. And we did recover some items of interest."
Investigators have been eyeing Rader's possible connection to the unsolved 1976 disappearance of Cynthia "Cyndi" Dawn Kinney in Osage County, Oklahoma, for months – and they've expanded their scope to look at possible connections with other unsolved cases in the region.
Cynthia Dawn Kinney was last seen on June 23, 1976, in Pawhuska, Oklahoma. Dennis Rader, also known as the serial killer BTK for his method of using "Bind, Torture, Kill" on victims, was active about 2 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)
Kinney was last seen leaving her aunt and uncle's laundromat in Pawhuska, about a 2-hour drive from where Rader lived at the time.
Rader has denied involvement in any cases aside from the 10 murders he pleaded guilty to after his capture in 2005.
"We weren’t looking for bodies, we were looking for items," Virden said. "We did find some items. We can't release what they are."
SERIAL KILLER BTK SAYS PRISON CELL SEARCHED AMID COLD-CASE PROBES; DENIES INVOLVEMENT
It was also not yet clear whether the newly recovered evidence is connected to the 10 known murders or other cases, the sheriff added.
Serial killer Dennis Rader stands before Sedgwick County District Court Judge Greg Waller as sentencing is read Aug. 18, 2005 in Wichita, Kansas. Rader received nine life terms and a "hard 40" for the 10 murders he committed over nearly 30 years. (Bo Rader-Pool/Getty Images)
"I don’t know yet if they're related to new crimes," the Oklahoma sheriff said. "With the information we developed where these items were, items that were never located, I absolutely believe they're related to Dennis’ crimes."
On Tuesday, with the search underway, Rader's daughter Kerri Rawson told Fox News Digital she believed investigators were searching for trophies her father may have hidden on the property.
In this handout image provided by the Sedgwick County Sheriff's office, BTK murder suspect Dennis Rader stands for a mug shot released Feb. 27, 2005 in Sedgwick County, Kansas. Rader is the suspect whom police have arrested on suspicion of first-degree murder in connection with the 10 deaths now tied to the serial killer known as BTK. (Photo by Sedgwick County Sheriff's Office via Getty Images) (Getty Images)
"The theory is he could have placed evidence of cases under stone pavers under the metal shed he built early to mid '90s, like drivers licenses in jars," she said.
Authorities are expected to release more information this afternoon.
"Our concern is more for the families," he said. "I hate tearing open old wounds, but we've still got to follow the leads we've got, where they go, and we'll try and be as respectful as we can to everybody involved and still do our job."
This is a breaking news story. Check back with Fox News Digital for updates.