Man charged in stabbing death of woman at Winchester Public Library found not guilty by reason of insanity

WOBURN, MASS. (WHDH) - A man charged in the vicious stabbing death of a 22-year-old woman at the Winchester Public Library has been found not guilty by reason of insanity.

Jeffrey Yao, 27, waived his right to a jury trial during an appearance in Woburn District Court on Wednesday morning just as he was set to go on trial for murder in the February 2018 death of 22-year-old Deanne Kenny Stryker, according to Middlesex District Attorney Marian T. Ryan.

Yao, who has been diagnosed with schizophrenia, approached Stryker from behind in the library’s reading room and stabbed her 20 times, according to prosecutors.

Stryker, a medical student, was home for the weekend visiting family and studying inside the library on a busy Saturday afternoon when she was killed.

Yao was also charged with stabbing 77-year-old Lester Taber, a bystander who tried to stop the knife attack. Taber has since recovered from his injuries.

At the request of the prosecution, Judge Kathe Tuttman ruled that Yao was not guilty by reason of lack of criminal responsibility and ordered him committed to Bridgewater State Hospital under strict security.

“He didn’t think he was killing someone,” Yao’s attorney JW Carney told the court. “He thought he was stopping the voices that had been tormenting him for the previous six years.”

Yao’s commitment to the state hospital will be reviewed after six months and then again on a yearly basis.

When Tuttman asked Yao if he understood that he could be committed for the rest of his life, he said, “Yes your honor.”

Carney added that Stryker’s death was a “horrible tragedy for everybody involved.”

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