Upon discovery of the remains, the Kansas City Police Department classified the case as a homicide, according to the news station. The remains - both human skulls - were found Monday and Tuesday, the sheriff's office said. Searchers found a second skull in the same area on Tuesday.
Kara Kopetsky, 17, went missing in May 2007 and has never been found. Jessica Runions, 21, another Missouri native, went missing in September 2016 and has endured a similar fate since.
Yust is now in custody on charges of setting Runions' auto on fire, but he has not been charged in either girls' disappearance.
Police only called Kopetsky's family, but when they found out Runions' mother was with them, they said to bring her too.
Runions, described by family as sweet and someone who rarely got mad, was last seen leaving a gathering of friends in south Kansas City. He said identification could take quite awhile.
Because the second skull appears to be much older, it could take months to identify.
"I'm hoping for a resolution after 10 long years of waiting", Beckford said.
"In my heart of hearts, I believe it's Kara", Beckford said.
Due to the decomposition of the second set of remains, it could be up to a year before they are positively identified.
"Right now, we really don't have a time frame of when we will have results on the other victim", Capt. Kevin Tieman, of the Cass County Sheriff's Office, said Wednesday evening. The teen later went to the office and picked up the book her mom had dropped off, but later that morning was seen on a surveillance camera inexplicably leaving the school. His trial on that charge is set for October. The host of that party told her family she left with Yust.
Kopetsky's family firmly believe that Yust is responsible for her disappearance. I'm glad they were together'. He insisted he didn't know where she was. Good or bad, we just want them home, ' Beckford told Fox 4 KC. "The only thing I can say is we're nearly there".
It was not immediately clear whether Yust, 28, will face additional charges now that the remains have been found. He has been charged in Jackson County with "knowingly burning" in connection to Jessica Runions' case and auto. And after the brief hearing, Linda Runions, her grandmother, pleaded for anyone with information to come forward.