Inset: Wyatt Testerman (Kenton County Detention Center). Background: The area in Kentucky where Testerman brutally killed his grandmother (Google Maps).
A 19-year-old Kentucky man admitted to killing his grandmother in a brutal, unprovoked attack, hitting and kicking the 74-year-old victim more than 50 times before beating her head in with a metal drinking tumbler.
Wyatt Testerman on Tuesday appeared in Kenton County Circuit Court, where he pleaded guilty but mentally ill to one count of murder in the October 2024 slaying of Cheri Oliver. The plea permits Testerman to receive mental health treatment during his incarceration.
According to a report from the Cincinnati Enquirer, Testerman entered a guilty plea without a prior agreement with prosecutors, who said they will still seek the maximum penalty of life in prison.
Testerman acknowledged in court that he attacked his grandmother while struggling with substance abuse.
"I had been abusing acid for quite some time," he reportedly said. "Without reason on that date, I attacked my grandmother, striking her numerous times and killing her."
As Law&Crime previously reported, Testerman was arrested in October 2024 after police responded to a family dispute at a residence on Ridgewood Drive in Erlanger. Officers found 74-year-old Cheri Oliver suffering from severe head trauma; she was transported to a hospital but did not survive.
Investigators later said Testerman admitted to repeatedly beating Oliver with his fists and a metal drinking tumbler, while witnesses described him becoming violent "for no apparent reason."
Prosecutors revealed in court filings that Testerman recorded the attack on his cellphone, setting up the device before shoving Oliver to the floor and repeatedly striking and stomping her.
Authorities said Oliver was struck more than 40 times and stomped roughly a dozen times, ultimately dying from blunt force trauma to the head.
At one point during the assault, he allegedly paused to check her pulse and said, "How the f— is she still breathing?" before grabbing a "metal drinking tumbler" and continuing the attack.
Testerman's mother reportedly told police she witnessed the attack and struck her son with a cane in an attempt to stop it, while another witness reported hearing him make disturbing statements beforehand, warning the victim she would "suffer the consequences."
The case had been set for trial, where Testerman initially planned to pursue an insanity defense. However, his attorney reportedly said a defense expert later determined he suffers from antisocial personality disorder and that he was "very likely under a psychotic episode based upon voluntary drug use," which does not meet the legal standard for insanity.
During the plea hearing, Testerman reportedly told the court he was experiencing hallucinations but understood the proceedings.
"I didn't spend too much time thinking in reality," Testerman reportedly told the court.
Prosecutors said his history of psychosis has consistently been tied to drug use.
Testerman now faces a prison stint ranging from 20 to 50 years or life when he appears before Judge Patricia Summe for his sentencing hearing on July 7.