Killer Enters Plea After Torturing Neighbor Girl to Death, Throwing Her in Freezing Pond to Release ‘Demons’

A Missouri man pleaded guilty Tuesday to murdering a 4-year-old girl, in what he said was an attempt to exorcise demons from her.

According to Benton County Circuit Court online court records, Ethan Mast pleaded guilty to reduced charges of second-degree murder and one count of first-degree or attempted assault “involving serious physical injury or a special victim.”

As CrimeOnline previously reported, Mast and his wife, Kourtney Aumen, 21, were charged in 2020, in connection with the death of 4-year-old Jessica Mast. Authorities said the pair, who were neighbors of the child, beat and tortured her, then dunked her in a freezing pond.

Benton County police officers were dispatched to a Benton County home on December 20, 2020, after Jessica’s father, James Mast, called 911 just before 1 a.m. James Mast said that the neighbors severely beat Jessica’s mother and their 2-year-old son. He added that his badly-beaten 4-year-old daughter, Jessica, was unresponsive inside a bedroom in the home.

Police said Ethan Mast is not related to the family.

Kourtney Aumen and Ethan Mast [Benton County SO]

Disturbing Details in Probable Cause Statement

According to court documents, James Mast told investigators that Augmen and Ethan Mast went to the same church as his family. He indicated that the suspects arrived unannounced at their home and declared that Mary Mast and Jessica had demons in them and needed to be “disciplined.”

Over the course of several weeks, the neighbors beat two of the Mast children and forced the parents to comply, warning them that they would get hurt if they interfered. James Mast said the suspects would leave the home periodically but would watch the family through security footage on their cellphone.

When the neighbors returned to the Mast home, the defendants unplugged the security camera before the beatings.

Jessica Mast
Photo: Kidwell-Garber Funeral Homes

On December 19, 2020, the defendants arrived back at the home at 8 a.m. and began beating the 2-year-old, while forcing the parents to watch, according to police. They left the victims’ home at some point that day, then returned later and began beating Jessica with a belt. She cried for help, but no one attempted to stop the beating.

The suspects eventually beat Mary Mast. Authorities found her inside a bedroom with her two sons, the 2-year-old and an infant. She had “severe bruising” all over her back, ABC 13 reports. The 2-year-old had severe bruising and blisters. They were both sent to an area hospital for treatment.

The infant boy appeared unharmed, and James Mast, who said he was beaten with a wooden spoon for showing compassion to his family, didn’t require hospitalization.

James Mast said the suspects told him “Satan would come” if he showed compassion.

James and Mary Mast
James and Mary Mast [Benton County SO]
When police arrived at the home on December 20, James Mast led them to an upstairs bedroom, where Jessica was on the floor near bunk beds, deceased. She had open wounds that appeared to be ruptured blisters and bruises that resembled belt marks.

Mast said the suspects took the girl to a pond and “dunked” her numerous times before leaving her on the bank to freeze. Afterward, they returned the child to her home, where she was wrapped in a blanket and left in the bedroom. It’s unclear exactly when the child died.

Sgt. Wilson asked James Mast, “how he could let people do this to his family and he stated they were told (his wife) had a ‘demon’ inside her and her children would end up just like her if it was not taken care of,” per the probable cause statement.

“Based on what I know, I think this could be some kind of honest-to-goodness religious-type episode,” Benton County Sheriff Eric Knox previously told KTLA 5.

It’s unclear whether Ethan Mast’s plea deal will lessen his sentence. He faces possible life in prison. His sentencing is scheduled for a later date. Check back for updates.

Meanwhile, Aumen successfully petitioned to have her case transferred to a different county, Law & Crime reports. Records regarding her court dates are unavailable, according to the outlet.

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[Feature Photo: Handout]