Authorities in Kansas say they have found “items of interest” in several cold case investigations during a search of “BTK killer” Dennis Rader’s former home. Osage County Sheriff Eddie Virden told Fox News that investigators had dug up Rader’s former property in Park City over two days this week after linking him to unsolved missing person cases. “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,” Mr Virden told the news site. He said officers “did a dig in the area, and we did recover some items of interest”. Rader is serving 10 consecutive life terms after his 2005 confession to the brutal murders of 10 women in the Wichita area between 1974 and 1991. Investigators have reportedly linked Rader to the unsolved disappearance of Cythia “Cyndi” Dawn Kinney, a 16-year-old cheerleader who disappeared from a laundromat in Pawhuska, Oklahoma, in 1976. Rader’s daughter Kerri Rawson said in a press release that she had been assisting law enforcement with an investigation into Kinney’s disappearance and several other unsolved murders. Ms Rawson said she had recently learned of Kinney’s cold case, and the separate unsolved murder of Shawna Garber, whose remains were found near Pineville, Missouri, in 1990. She said she contacted the law enforcement in Missouri and after being put in touch with the Osage County Sheriff’s Office she was flown to Kansas to work as a volunteer in both cases. As part of that work, she said she visited her father twice at the El Dorado Correctional Facility where he is incarcerated. “Beyond these two cases that have been released publicly, I’m not at liberty to discuss other possible missing persons and unsolved murder cases that are being actively investigated as possibly committed by my father, nor can I comment on my direct assistance in the investigations,” Ms Rawson said. “Multiple law enforcement agencies are seeking long-sought answers in decades-old missing persons and unsolved murder cases in the tri-state area of Kansa, Missouri and Oklahoma. And possibly locations that extend beyond the tri-state area,” she added. Ms Rawson also revealed that Rader had this year been offered immunity to confess to any violent crimes he may have committed between the early 1960s and his arrest in 2005. She called on local, state and federal law enforcement agencies to form a BTK killer special task force “to fund and power these vital ongoing tasks”. Read More BTK killer makes chilling comparisons between himself and Gilgo Beach murders suspect Rex Heuermann Bryan Kohberger defence hints at alibi in Idaho murders - but won’t reveal what it is as deadline passes Four students stabbed to death, a weeks-long manhunt but no motive: What we know about the Idaho murders