WICHITA, Kan. (KSNW) – The Wichita Police Department received a subpoena from the Osage County Sheriff’s Office to review evidence they have linked to Dennis Rader, BTK.

The OSCO is looking into connections he may have to cold case investigations.

In April, the OCSO visited the lot in Park City, where Rader’s home once stood. They say they dug up “pantyhose ligature” they believe Rader used to tie up victims.

KSN asked Captain Christian Cory with WPD how the OCSO found evidence connected to BTK over 18 years after WPD investigated.

“I think that’s the question, and that’s the assumption, but we don’t know,” said Captain Cory.

When asked to clarify what he meant by “that’s the assumption,” Captain Cory said, “Well, you’re saying it’s evidence. Is it? That’s my answer. I don’t know.”

KSN asked if the items found by the OCSO aren’t evidence, what is it?

“I don’t know. Like I said, I don’t know how that little park (house lot), or whatever, was created. If it’s just something that was there,” said Captain Cory. “As an investigator, you have to go where the evidence leads you, and you can’t ignore other evidence.”

There is no timeline for when the OCSO will look at evidence from WPD.