BTK murderer Dennis Rader stands for a mug shot released February 27, 2005 in Sedgwick County, Kansas.Photo:Sedgwick County Sheriff’s Office via Getty

In this handout image provided by the Sedgwick County Sheriff’s office, BTK murder suspect Dennis Rader stands for a mug shot released February 27, 2005 in Sedgwick County

Sedgwick County Sheriff’s Office via Getty

Dennis Rader, the notorious murderer known as the “BTK” killer, is the “prime suspect” in two unsolved murders, according to a release from the Osage County Sheriff’s Office in Oklahoma.

The sheriff’s office, which recentlydug up the former property of Raderin Park City, Kan., said “items of interest were recovered at the residence,” according to thestatement.

In an exclusive interview with PEOPLE, Undersheriff Gary Upton tells PEOPLE, “Our next steps are to work in collaboration with the FBI to identify pieces of evidence in their possession that match pieces of clothing that we’ve seen in polaroid pictures that Dennis Rader took, and see if those items match the DNA of our victims.”

BTK Serial Killer Dennis Rader Named as Prime Suspect in 2 Unsolved Murder

Osage County Sheriff’s Office

“One item in particular is a red blanket seen in one of those polaroids that we believe belonged to Shawna Beth Garber,” Upton says. “That would help to advance our case further."

According toTheAssociatedPress, Garber, 22, was raped and strangled to death in 1990. Her body remained unidentified until 2021.

Convicted serial killer Dennis Rader, known as the BTK strangler walks into the El Dorado Correctional Facility with two Sedgwick County sheriff’s officers on Friday, Aug. 19, 2005 in El Dorado, Kansas.Jeff Tuttle/The Eagle via AP

Convicted serial killer Dennis Rader, known as the BTK strangler walks into the El Dorado Correctional Facility

Jeff Tuttle/The Eagle via AP

Sheriff Eddie Virden visited the Kansas prison where Rader is currently serving multiple life sentences, according to12 News. He told the outlet the convicted killer spoke to him about his life — starting at age three — and the events leading up to him being in prison, including his 10 murders in the Wichita area.

According to Virden, Rader denied involvement in Kinney’s disappearance, but confessed to a fantasy about kidnapping a girl from a laundromat, per the outlet.

“He explained to me that he would watch the laundromat ‘til she was in there alone,” Virden told 12 News. “He’d go in with a rouse and get her to his vehicle, and he’d have her and nobody would see or hear anything.”

An auction sign stands at the driveway of the house at 6220 N. Independence were Dennis Rader, the admitted BTK serial killer, lived with his wife and two children July 11, 2005 in Park City, Kansas.Larry W. Smith/Getty

An auction sign stands at the driveway of the house at 6220 N. Independence were Dennis Rader, the admitted BTK serial killer, lived with his wife and two children July 11, 2005 in Park City, Kansas.

Larry W. Smith/Getty

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Last February, Virden toldFOX 23"We never close the door on a case just because it goes cold. And we didn’t want to rule him out, and we’re still not ruling him out."

Kerri Rawson, Rader’s daughter, previously spoke toPEOPLEabout her father’s 2005 arrest.

“It took more than 10 years before I could even sit across from someone and even talk about this,” Rawson said at the time. “Nobody wants to believe their father could be capable of such monstrous things.”

“I was just trying to stay alive and breathe,” she added. “Trying to recover from the shock, telling myself over and over that I’d do anything not to be the daughter of a serial killer.”

Virden did not immediately respond to PEOPLE’s request for comment.

source: people.com