CASS COUNTY, Mo. -- (WDAF) -- The man long-believed to be a killer is now suspected of murder. On Thursday Cass County prosecutors formally charged Kylr Yust with two counts of first-degree murder and two counts of abandoning a corpse related to the disappearances and killings of Kara Kopetsky in 2007 and Jessica Runions in 2016.
Runions disappeared after she left a party with him in September 2016. Kopetsky vanished more than 10 years ago after she was last seen walking out of Belton High School.
A decade separated the disappearances, but their remains were found near each other, just a few days apart in April 2017 when a mushroom hunter stumbled upon bones in rural Cass County. Yust has been in jail and charged with burning Runions' car in Jackson County, where he is still in custody.
Court papers show that the prosecutor's case started back on April 28th of 2007 -- days before Kopetsky disappeared. She told police that Yust kidnapped her after they broke up.
A judge granted her request for a restraining order on April 30th, four days before it's believed that she was killed. Kopetsky was just 17 years old when she disappeared, and was last seen leaving Belton High School in May of 2007.
Court records show that over the years investigators tried to crack Yust multiple times.
Between April of 2010 and June of 2012, multiple people who knew him called police saying Yust admitted to choking Kopetsky to death.
Yust was sentenced to federal prison for drug distribution in November of 2013, and put on supervised release on September 2, 2016. That court order reads:
"You shall serve one weekend confined at a facility designated by the Bureau of Prisons. You shall report to the designated facility, as instructed by the probation officer, on Friday at 7:00 p.m. and will be released the following Sunday at 7:00 p.m. You are to pay subsistence as directed."
On September 9, 2016, Runions was reported missing a day after leaving a party with Yust where he was behaving possessive of Runions and acting aggressively towards others according to witnesses. They said Yust was drinking heavily at the party and arguing with Runions.
Police found her burned-out car on September 10. A man who was with Yust that same day told police that he drove Yust to his home in Edwards, Mo., and he was recovering from burns he received setting Runions' SUV on fire. The SUV was found in the area of 95th Street and Blue River Road. That man told police that Yust said he strangled Runions and "she was gone." Yust added that he had dragged her body into the woods.