Seven months after she went missing, the remains of 21-year-old Jessica Runions were positively identified on Wednesday, PEOPLE confirms. 
 
 According to Kansas City authorities, a civilian stumbled upon the remains in a rural area of Cass County. With the grisly discovery, Runions’ case has become a homicide investigation, authorities said in a statement. 
 
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 Jessica Runions was a baker at a retirement home. She was last seen on Sept. 8, 2016 when she left a party in Kansas City with Kylr Yust, a friend of her boyfriend’s. Days later, her empty vehicle was found abandoned and burned. Yust was arrested and charged with intentionally burning her vehicle. He has pleaded not guilty. 
 
 It was not immediately clear whether Yust, 28, will face additional charges now that the remains have been found. 
 
 Yust was once a suspect in the disappearance of his former girlfriend, Kara Kopetsky, the Kansas City police have said. She was last seen at Belton High School in May 2007. She was 17. 
 
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 Authorities tell PEOPLE that a second set of remains has been found in the same location as Runions’, but it could take weeks or even months to identify them — and that it’s premature to speculate whether they belong to Kopetsky. 
 
 Captain Kevin Tieman with the Cass County Sherriff’s Office tells PEOPLE that investigators are still searching for additional remains at the scene. 
 
 Yust’s attorney, Molly Hastings, has not returned PEOPLE’s request for comment. 
 
 This is not the first time that Yust has been in legal trouble. 
 
 In September 2011, Yust pleaded guilty to domestic violence after choking and striking his then-pregnant 18-year-old girlfriend, according to a police report obtained by PEOPLE. The victim claimed Yust told her, “I’ve killed people before, even ex-girlfriends out of sheer jealousy. I will kill you.” 
 
 The victim also alleged Yust told her he had killed her three kittens and would kill her family if she went to police. A Kansas City judge filed an order of protection, which was later dismissed, court records state. 
 
 Yust is currently in custody. ||||| KANSAS CITY, Mo. -- A Missouri man connected to two Kansas City-area women who disappeared about 10 years apart was charged Thursday with their murders. 
 
 Cass County authorities charged Kylr Yust with two counts of first-degree murder and two counts of abandoning a corpse in the deaths of Kara Kopetsky, 17, of Belton, and 21-year-old Jessica Runions of Raymore. He is being held on $1 million bond. 
 
 Authorities had long suspected Yust was involved in Kopetsky's and Runions' disappearances. Runions was seen leaving a gathering with Yust before she disappeared in September 2016 and Kopetsky had filed a protection order against Yust in April 2007, a month before she went missing after walking out of Belton High School. 
 
 In the protection order, Kopetsky said Yust had kidnapped and restrained her, choked her and threatened to cut her throat during their nine-month relationship. 
 
 KCTV 
 
 "I'm unsure what he will do next, because the abuse has gotten worse over time," the application for the court intervention read, alleging Yust stalked Kopetsky and inflicted emotional and physical abuse. 
 
 A hearing was scheduled for May 10, 2007 but Kopetsky went missing six days before the hearing. 
 
 In April, a mushroom hunter found human remains that were quickly identified as Jessica Runions in a wooded area south of Belton. The next day, Kopetsky's remains were discovered nearby but not positively identified until August. 
 
 Yust was already jailed on a charge that he burned Runions' car. Online court records do not indicate that Yust has an attorney. 
 
 In the years after Kopetsky disappeared, Yust confessed to friends, roommates and cellmates that he killed her because he was upset that she wanted to end their on-and-off relationship, according to a probable cause statement released Thursday. He allegedly kidnapped Kopetsky as she left her job about a week before she disappeared and drove around for several hours arguing before she was allowed out of the car. 
 
 Phone records showed Yust and Kopetsky exchanged phone calls within minutes of her leaving Belton High School on May 4, 2007, the last time she was seen alive, the statement said. 
 
 A friend told police in April 2010 that Yust had told him about his volatile relationship with Kopetsky. 
 
 "(The witness) stated Yost then told him the victim K.E.K. wouldn't love him and that he was angry with her because he didn't want her to love someone else," according to the statement. "Yust then told (the witness) that he had just snapped, and that something bad happened to the victim." 
 
 Other witnesses told investigators that Yust confessed to choking Kopetsky to death and said he stared at her body for a long time before putting the body in a car and taking it to the woods. He also said no one would ever find the body, the statement said. 
 
 In the Runions case, witnesses told police she and Yust were arguing and he was drunk and being possessive toward her before they left a party in Grandview. Two days later, Kansas City firefighters responded to a burning vehicle report and determined the car belonged to Runions. 
 
 A friend told police he was with Yust when he burned the vehicle and took him to his house to recover after Yust suffered burns on his hands and face. The friend notified Belton police that Yust told him he had strangled Runions and taken her body into a wooded area, according to the statement. 
 
 Yust was arrested on Sept. 11, 2016 at an Edwards, Missouri, mobile home. 
 
 Kopetsky's mother Rhonda Beckford and Runions' mother Jamie Runions have long suspected Yust in their daughters disappearances, reports CBS affiliate KCTV. 
 
 "I can't put it any other way but I hate him," Beckford told the station after his arrest. "I hate him for taking not only my child, but now possibly taking another." 
 
 The families said they'll work together to seek justice for their daughters and thanked the community for their support. 
 
 "Their strength, their support, their prayers – it's just unbelievable how much they love our girls," Jamie Runions said.
– Police in Missouri have had to give the parents of Jessica Runions the news they dreaded: One of two skulls found outside Kansas City this week is that of their 21-year-old daughter, who disappeared in September. Police say the case is now a homicide investigation, People reports. Authorities say that identifying the other human remains could take weeks or months. The area in rural Cass County is still being searched for additional remains. The family of Kara Kopetsky, a 17-year-old who disappeared in 2007, was notified when the remains were found. Both Runions and Kopetsky were linked to the same man, 28-year-old Kylr Yust, who was charged with "knowingly burning" Runions' car after she vanished. It's not clear whether Yust will face additional charges now that Runions' remains have been found. "Kylr has not been charged with anything, with anything outside of knowingly burning a car, again ... and that we intend to fight," his attorney told ABC News before the remains were identified. Runions was last seen leaving a party with Yust, who was a friend of her boyfriend. Yust was also a suspect after Kopetsky, his ex-girlfriend, disappeared. In 2011, he pleaded guilty to domestic violence after choking another girlfriend. She told police he threatened to kill her, telling her he had "killed people before, even ex-girlfriends, out of sheer jealousy."