Kourtney Taylor Aumen pleaded guilty to second-degree murder in the death of Jessica Joy Mast. Sentencing is Dec. 21.

A guilty plea to second-degree murder and first-degree assault is an admission on those two counts. It is not the sentence, and it is not a plea to the first-degree murder count she had been facing. ABC17 reported the Monday hearing showed up on CaseNet the same morning, in front of a trial that had been set for Oct. 26. Dec. 21 is when a judge has to decide the punishment on the counts she admitted. The other three adults have their own pleas. Those pleas are not her sentence.

ABC17 reported that on Monday afternoon, Oct. 5, 2026, Kourtney Aumen, 27, pleaded guilty to second-degree murder and first-degree assault in the death of 4-year-old Jessica Mast. Law&Crime reported the same plea under the name Kourtney Taylor Aumen and identified the child as Jessica Joy Mast. ABC17 reported she will be sentenced at 1:30 p.m. Monday, Dec. 21, and that the hearing appeared on the CaseNet docket Monday morning ahead of a trial set for Oct. 26. Law&Crime reported the trial had been scheduled to begin Oct. 26 and that the online docket showed a change-of-plea hearing was held. ABC17 reported she had been charged with first-degree murder, assault, armed criminal action, child abuse, and child endangerment. The plea ABC17 and Law&Crime reported is to second-degree murder and first-degree assault. It does not, on those accounts, include a plea to first-degree murder. A change of plea on the morning the case had been headed to trial is the admission. The punishment is not imposed until Dec. 21.

KY3 and Law&Crime date Jessica's death to December 2020. ABC17's Oct. 5 story wrote December 2021. KY3's Nov. 25, 2024 account, citing investigators, reported that on Dec. 19, 2020, the 4-year-old was dunked into an icy pond and beaten, and that Benton County deputies responded at 1 a.m. on Dec. 20 to a rural home near Cole Camp and found her wrapped in a blanket on a bedroom floor, already dead. That 2024 story reported investigators described severe purple bruising and ruptured blisters, and that Sheriff Eric Knox said evidence indicated she was beaten to death, while also reporting that an autopsy would determine the cause of death. KY3's Oct. 6, 2026 story reported prosecutors say that after Jessica and another child were beaten, the 4-year-old was held under freezing water in a farm pond. The other child is not named here. KY3 reported in 2024 that Knox said a 2-year-old was also beaten and that an infant was apparently unharmed. Those children are not named in the reports used here. What a sheriff told a station in 2024, and what prosecutors are described as saying after a 2026 plea, are accounts of the accusation she admitted in part. They are not the judgment the judge has not yet imposed.

The accounts of why it happened are not the same document. KY3 reported Oct. 6 that Aumen was accused of telling Jessica's parents and another woman that the girl could be demon-possessed. ABC17 reported that court documents claim James and Mary Mast, the parents, told deputies that Aumen and their neighbor, Ethan Mast, put them through the abuse to rid them of a demon. Law&Crime reported that James Mast told investigators the neighbors caused the injuries, and that he said they were told the mother had a demon inside her. Ethan Mast is not related to Jessica, KY3 and Law&Crime reported. A parent's statement to investigators and a charging narrative about a demon are not the same as the two counts Aumen admitted on Monday.

The other three adults have plea histories that are not Aumen's sentence. KY3 reported in 2024 that James Mast accepted a deal to second-degree murder and first-degree assault, with other counts to be dismissed if he cooperated, and that he would not be sentenced until Aumen's case was resolved. KY3 reported Oct. 6, 2026, that he rescinded that plea a month after the November 2024 hearing, that an April order denied his motion to withdraw it, and that he has filed more motions, with no new court date reported. Law&Crime's Oct. 7 story described his plea to second-degree murder and first-degree assault as entered. KY3 reported Mary Mast pleaded guilty in 2023 to endangering the welfare of a child and was due in court Wednesday, Oct. 7. No result from that Wednesday setting appeared in the stories used here. KY3 reported in 2024 that Ethan Mast entered a guilty plea in February 2022 and was awaiting sentencing. Law&Crime reported he pleaded guilty to second-degree murder. ABC17 reported Aumen is in the Benton County Jail. Monday's plea fixed the counts she admitted. It did not fix the years. All defendants are presumed innocent until proven guilty in a court of law.