Sergio Koyangbo, 21, of Bethesda was found guilty on Monday–but not criminally responsible–for the 2022 stabbing death of his stepfather, David Beasly, 46, according to a release from the Montgomery County State’s Attorney’s Office.
According to the State’s Attorney’s Office, not criminally responsible is Maryland’s version of an insanity plea.
The stabbing occurred on March 5, 2022 at the Bethesda home of Beasly and Koyango’s mother, according to charging documents. Koyangbo approached Beasly, accused him of looking at his internet search history and stabbed Beasly in the chest, unprovoked, charging documents stated. Koyango’s mother called 911, according to court documents.
At 9:30 p.m., officers said they responded to the 5600 block of Lambeth Road in Bethesda and found Beasley with apparent stab wounds. Fire and Rescue personnel transported him to an area hospital and Beasly succumbed to his injuries, according to charging documents.
Koyangbo was then arrested and charged with first-degree murder, police said.
Andrew Jezic, Koyangbo’s attorney, said that Koyangbo’s extreme mental illness, which caused deep anxieties and hallucinations, played a huge role in his actions that night.
“It caused him to have this distorted, hallucinatory way of thinking,” Jezic said. “It got worse, worse and worse, and it became dominant over his voluntary actions.”
In December 2022, after a state expert concluded that Koyangbo was not criminally responsible, the State countered with their own independent evaluation by one of Maryland’s leading forensic psychiatrists. However, their psychiatrist arrived at the same finding as the state expert, so the State conceded that issue, according to the release.
DeMarco said the State’s Attorney’s Office often brings in an independent doctor to evaluate a case. However, in some cases, where the determination is more obvious, like when someone has a long history of an extreme mental illness, they may not need another opinion.
The standard in Maryland is that if someone’s mental illness prevents them from conforming their conduct to the requirements of law, they will likely be considered not criminally responsible, according to Jezic.
Jezic said that this is the “humane” way of holding mentally ill people accountable in the justice system.
After Monday’s hearing, Koyangbo was committed to the Maryland Department of Health. He will stay in a medical facility, and the duration of his stay will be determined by future evaluations, the release said.
Jezic said Koyangbo could be in the facility from four to 40 years, depending on the progress of his treatment.