The man accused of fatally stabbing a 22-year-old woman at a public library in Winchester, Massachusetts, was found not guilty Wednesday by reason of insanity.
Jeffrey Yao, 24, of Winchester, was charged in the 2018 murder of Deane Kenny Stryker and the assault of a 77-year-old man who attempted to intervene at the Winchester Public Library.
The judge reached a not guilty verdict after three medical experts said Yao was mentally ill during his attack and could not be held criminally responsible because he did not have the capacity to appreciate the wrongfulness of his conduct or the ability to conform his conduct to the requirements of the law.
Yao allegedly walked into the library on February 24, 2018, and randomly attacked Stryker with a 10-inch hunting knife, stabbing her approximately 20 times in the head, neck and other extremities. He also allegedly slashed an elderly man who attempted to help the victim in the arm.
"Miss Stryker fell to the floor in the center of the room with the knife still in her back," prosecutors said in court after Yao's arrest. "The defendant, who was then unarmed, stepped away from Miss Stryker and put his hands in the air."
Stryker was taken to a local hospital, where she later died.
“Deanne Stryker was an amazing young woman planning a life full of promise and service. No outcome in this case can ever diminish the great tragedy of her death or fill the void left in the lives of her mother, sisters and others who loved her," Middlesex District Attorney Marian Ryan said in a statement Wednesday. "While today marks the end of this criminal case for the Stryker family, the brave gentleman who tried to save Deanne and the many witnesses who were in the Winchester Public Library that day, the effects of that painful day remain.”
Yao was charged with murder, armed assault with intent to murder a person over the age of 60 and assault and battery with a dangerous weapon on a person over the age of 60.
Following the insanity verdict, he will be sent to Bridgewater State Hospital, a maximum security facility.
Yao had waived his right to a jury by trial, opting instead for a bench trial.
His attorney, J.W. Carney, did not object. He said his client is schizophrenic and his parents tried unsuccessfully to get help for their son.