Remains found last week in a Southeast Texas pasture are those of missing University of North Texas student Kelli Cox, according to Denton police.
Cox was 20 years old when she disappeared in July 1997. No one has been charged in her disappearance or death, but 56-year-old William Reece, an imprisoned kidnapper linked to several other cases, led police to her skeleton.
It was the second time in two months Reece was temporarily released from prison so he could lead Texas authorities to a set of human remains. The other body, which has not yet been identified, may belong to Jessica Cain, who was 17-years-old when she disappeared in 1997, authorities said.
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Denton police said Monday the remains found last week in Brazoria County belonged to Cox.
"Through forensic analysis of dental records by The University of North Texas – Center for Human Identification and Laboratory of Forensic Anthropology and the Galveston County Medical Examiner's office, an identification has been made from the human remains recovered by Investigators in Brazoria County on April 5, 2016. Those remains have been positively identified as Kelli Ann Cox," officials said in a news release.
The investigation into Cox's death is ongoing, according to Denton police. Her remains will undergo further DNA analysis.
Reece is cooperating with investigators and will have more conversations with Denton detectives assigned to the case, Denton Police spokesman Shane Kizer said. Kizer added he expects formal charges to come in the near future.
In an interview with NBC 5 on Monday, Cox's mother, Jan Bynum, said a Denton police detective confirmed with her the discovered remains belonged to her daughter.
"I have not completely processed it," Bynum said. "I'm trying to get my head and my heart wrapped around it. I've dealt with it for 19 years with an element of hope, then that hope has been pulled away and becomes reality."
Bynum said she had planned to drive down to the search area.
"She's in God's arms and now I can deal with other things that I need to deal with. I need to get her home and figure out the next steps. I know I want to drive down to the Houston area," Bynum said.
Reece is currently serving a 60-year sentence for kidnapping another woman — 19-year-old Sandra Sapaugh — but hasn't been charged in the disappearances of Cain or Cox, his attorney, Anthony Osso, said last week.
Reece faces first-degree murder and kidnapping charges in Oklahoma for the slaying of 19-year-old Tiffany Johnston, who was abducted from a car wash northwest of Oklahoma City in 1997. He was also previously named the prime suspect in the April 1997 abduction and killing of a 12-year-old girl in Friendswood, near Houston, but has not been charged.
Reece was sent to prison the following year for abducting Sapaugh in the Houston area in May 1997. Sapaugh told authorities Reece forced her at knifepoint into his truck after first pretending to help her with a flat tire. She escaped after jumping from the truck.
Asked why Reece decided to help authorities find Cox's remains, Osso said his client realized he already faced decades more in prison and had a serious heart condition.
"He wants closure for the families involved," Osso said. "I think he's at peace with the fact that he's going to remain in prison, probably die in prison."
Whether Reece has information on any other cases is unclear. Osso said authorities in other parts of Texas or elsewhere with similar cold cases might speak to Reece in the near future.
NBC 5's Caroline Connolly, Chris Jose and The Associated Press contributed to this report.