Updated

Recordings of 911 calls released Wednesday describe a frantic scene late last month at a Winchester, Mass., library, where authorities say a suspect armed with a hunting knife repeatedly stabbed a young medical student, resulting in her death.

“She’s lying down on her back,” a library staff member tells a 911 operator at one point, Boston’s Fox 25 reported. “Oh my God, there is a lot of blood.”

"She's lying down on her back. Oh my God, there is a lot of blood."

— Library staffer, in call to 911 operator

Authorities say suspect Jeffrey Yao, 23, killed Deane Stryker, 22, in what appears to be a random attack – although authorities noted that both had attended Winchester High School.

“This is the library. Somebody is stabbing someone. Please come. Hurry,” another caller says.

Prosecutors said that during the attack, Stryker managed to get up from her spot at a reading room table and run to the front lobby, with Yao following her, Fox 25 reported. Several witnesses tried to intervene, including a 77-year-old man who suffered a non-life-threatening stab wound to an arm.

Stryker, who was stabbed multiple times in the head and torso, was rushed to a hospital, but died of her injuries, authorities said.

Yao faces charges of murder and assault with intent to murder in the Feb. 24 killing of Stryker and the wounding of the elderly man, MassLive.com reported.

Earlier this month, Yao was transferred to Bridgewater State Hospital after officials from the Middlesex County Sherriff's Office told a judge he was too mentally ill to remain in jail.

In addition to the 911 calls, authorities released records of more than a dozen previous interactions between Yao and police, dating to 2012.

“We are releasing this information because it is in the public interest and because we believe that the public is served by the release of this information,” Winchester police Chief Peter MacDonnell told Fox 25. “Our officers brought this individual to a local hospital for mental health evaluations many times. It is my hope that the release of this information will contribute to the dialogue on mental health in our society.”

"Our officers brought this individual to a local hospital for mental health evaluations many times. It is my hope that the release of this information will contribute to the dialogue on mental health in our society."

— Winchester police Chief Peter MacDonnell

According to police, previous incidents included accusations that Yao wrote “inappropriate” social media posts, interrupted a high school lacrosse match and threw a shovel during an argument with a neighbor.

“Jeffery Yao is a troubled young man who has a long history of serious mental illness and multiple hospitalizations for the mental illness,” Yao’s attorney, J.W. Carney Jr., told Fox 25 soon after Yao’s arrest.

“He’s had a lot of contact with the Winchester police over the years [and] to their credit, they recognized he has a severe mental illness and dealt with him in that manner, by often taking him to a hospital instead of a police station.”

Stryker was studying at the University of New England's College of Osteopathic Medicine, in Biddeford, Maine, her family said.

The Associated Press contributed to this story.