A Missouri teenager, implicated in the fatal shooting of a decorated U.S. Marine during a Facebook Marketplace scam, has reportedly made threatening remarks to another individual just weeks before the incident, according to court documents. The teenager allegedly warned this person in text messages and phone calls that he would “shoot up his house.”

The accused, 18-year-old Kobe Aust, faces charges of second-degree murder, first-degree robbery, and armed criminal action for the killing of 42-year-old Ryan Burke. The shooting occurred on January 18 at Burke’s residence in Columbia, Missouri. In addition to these charges, Aust now confronts a first-degree harassment charge stemming from the alleged threats made to another local resident.

A probable cause affidavit filed by Boone County police outlines the case against Aust. He is accused of committing the murder alongside Joseph Crane, Alexis Baumann, both 18, and a juvenile accomplice. The affidavit reveals that on December 14, 2025, Aust threatened the harassment victim, indicating he would “crunch” him, which the victim interpreted as a threat to his life.

Authorities were provided with messages where Aust allegedly threatened to physically harm the victim, claiming he would “beat” him up and that the victim would face severe consequences if they ever engaged in a fight. The victim informed police of his belief that Aust possessed a firearm.

The affidavit includes statements from the victim, who mentioned seeing videos of Aust displaying a firearm online. The document notes that police reviewed a video on Aust’s personal Facebook page, where he is seen handling a gun with an extended magazine.

Fearing for his safety, the victim reportedly hid in his basement following the threats, expressing to law enforcement his belief that Aust intended to “shoot and kill” him, as per the affidavit.

“Aust knows where [the victim] resides and where [the victim] works,” the affidavit notes.

Aust, who is being held without bond for Burke’s murder, was informed Monday about the felony harassment charge and is scheduled to appear for a preliminary hearing on March 26.

For the murder case, cops say Aust and the others went to Burke’s home “under the ruse” of them wanting to buy his iPhone 15 Pro, which is valued at about $585, according to court documents.

“I’m here,” the juvenile suspect allegedly texted Burke after arriving with the group.

The teens arrived at Burke’s house around 8:10 p.m. after coordinating the meeting on Facebook, according to police. Baumann allegedly confessed during police interviews to riding with the teens to Burke’s home in her vehicle, with Crane and the juvenile suspect going inside to retrieve the iPhone while Baumann waited outside with Aust.

“Alexis advised she heard three gunshots from inside,” the court documents say. “Juvenile suspect #1 and [Crane] ran back out to her vehicle, and she drove away from the scene.”

Baumann allegedly told police that Crane and the juvenile “were both armed with pistols, and once back inside of her car” they admitted to shooting Burke and stealing his phone, “which they sold at the ecoATM at the Conley Rd. Walmart directly after the murder,” per the court docs.

“Hey, I’m dying and I love you,” Burke texted his mom and sister after being shot, according to family friend and fraternity brother Jerry Reifeiss, who spoke to local CBS affiliate KRCG about Burke’s death.

“He texted them saying that,” Reifeiss recounted. “That was just Ryan. He always put people in front of him and wanted to make sure people knew how he felt. He didn’t want to go on to the next life and pass away without providing some information to us here that would bring justice to these people and let people know he always loves them.”

Police say Burke, who reportedly did missionary work in Uganda, also managed to call police after being shot and “reported someone came to buy a phone from him, and the suspect shot him.”

While fleeing, Baumann alleged that Crane and the juvenile “threw their sweatshirts out of her car window,” which Aust corroborated in police interviews as well, according to police. He, too, allegedly said Crane and the juvenile were armed and went inside Burke’s home.

The group is accused of going on a robbery spree before killing Burke, during which they targeted at least two others for their phones.

“If you touch me I’ll shoot you,” the juvenile suspect told one of the victims after swiping her phone “when she showed it to him,” police say.

Surveillance footage obtained by police shows the teens allegedly selling the phones they stole at the same Walmart on Conley Rd. following all three robberies. Detectives were able to track down the group on Monday using Flock license plate cameras to locate Baumann’s car. She and Aust were taken into custody and interviewed about what happened, with Crane and the juvenile being arrested later in the day.

All four individuals are being held without bond.