SPRING VALLEY, N.Y. (CBSNewYork) — A simple request preceded a heinous crime at a Rockland County public library.

Police say a security guard asked a man to turn down the volume of his phone, just moments before he pulled a knife and attacked, reports CBS2’s Tony Aiello.

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Authorities say 25-year-old Blanchard Glaudin is facing second-degree murder charges and being held without bond after Spring Valley police say he killed a security guard inside the Finkelstein Memorial Library yesterday afternoon.

Witnesses say he charged into the building and repeatedly stabbed 53-year-old Sandra Wilson.

READ: Rockland County Felony Complaint On Blanchard Glaudin

The library is one place multiple communities – Hispanic, Jewish, Haitian – came together to interact and engage. Tonight they were unified in shock and horror but and showing support for the family of the victim.

“She truly, truly understood what it meant to be a sister, a mom, a daughter,” said Ronnie Wilson. “She always put her best foot forward. Always smiling, always trying to help people.”

Ronnie Wilson, the victim’s brother, says together his family will make it through this nightmare.

Spring Valley Community Remembers Slain Library Security Guard Sandra Wilson

Sandra Wilson was fatally stabbed at a Spring Valley library, where she worked as a security guard. (Photo Provided)

Earlier on Wednesday, Judge Tom Walsh told CBS2 that Glaudin was “disgruntled with our victim doing her job to provide a safe, secure and quiet environment for the people at the library.” Walsh also said mental health issues also might have been a factor.

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Abigail Jean-Marie, a library co-worker, says Sandra Wilson had earlier unpleasant encounters with the suspect.

“He would harass her, she would tell me that one day he asked her to be his girlfriend, and she was like no – he was constantly bothering her,” she said. “I didn’t think anything of it at the time, he was just a very strange person that would come into the library.”

“Right now I’m going to pray for him,” said Ronnie Wilson. “That’s what I can do right now. I can’t do anything else. I’m just empty inside right now.”

After Sandra Wilson was attacked on the third floor, some patrons administered first aid to stop the bleeding while others heroically chased and detained the suspect.

Thank you, much appreciated. They didn’t just stand by, they did something,” said Frank Wilson, Sandra’s brother.

“The smile and the greeting she had for everybody,” said Library Director Laura Wolven. “Her honesty and her integrity. She will be so, so missed.”

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The library closed after the tragedy Tuesday and is expected to reopen on Monday after a period of mourning and a security review.