Police were familiar with man accused of stabbing woman to death at Winchester library

WINCHESTER, MASS. (WHDH) - When police arrested the man accused of stabbing a 22-year-old woman to death inside the Winchester Public Library on over the weekend, authorities say they knew who they were dealing with.

Jefferey Yao, 23, had many run-ins with the law before police say he attacked and killed medical student, Deanne Kenny Stryker, at random.

It’s now known that officers in the town have had contact with Yao for years. The question know is: could something have been done to prevent the deadly attack?

In hopes of answering all that, police say they plan to release more than 100 papers documenting their interactions with Yao since he was just 18.

A source close to the Winchester Police Department told 7News that of all the encounters, as many as two-thirds were initiated by Yao contacting police himself.

In the last 3 years, police took Yao to the hospital three times and arrested him once for trying to break down a neighbor’s door.

When the incident reports are released, the names of callers who reported problems, witnesses, and victims will be redacted.

The news comes as Stryker, who was stabbed as many as 20 times while sitting at a reading table, is laid to rest and the community continues to grieve.

Police say the documents will be released upon completion of a legal review.

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