NEW YORK (CBSNewYork) — The NYPD says a woman who lives in the building where a 70-year-old woman was found dead with her throat slashed is a person of interest in the case.

As CBS2’s Jenna DeAngelis reported Monday, police are searching for a suspect and motive.

When Susan Trott did not show up for work, a worried co-worker asked police to conduct a wellness check. That’s when they made the gruesome discovery inside the building on West End Avenue — Trott found lifeless with her throat slit.

“I’m shocked, I’m very shocked. It’s very sad,” neighbor Amy Apicella said, adding Trott was “very sweet.”

“A 70-year-old woman found with her throat cut, that’s horrible,” said Upper West Side resident Terence Hanrahan.

susan trott NYPD: Female Person Of Interest Eyed In Upper West Side Woman’s Gruesome Murder

Susan Trott was found dead inside her luxury apartment on the Upper West Side on Oct. 21, 2018. (Photo: CBS2)

A trail of blood led police from Trott’s living room to her bedroom. Sources told CBS2 blood splatter showed a struggle, but there were no signs of a forced entry, there was no weapon found at the scene and the apartment was not ransacked. The building has doormen around the clock.

“I was totally unaware that she had any enemies or anything like that,” neighbor Helen Stein said.

Trott was described as an animal lover, generous, caring and eccentric. According to her website, she was a longtime copywriter, advertiser and creative consultant for major corporations, dividing her time between New York and London.

Her violent death has left people in this neighborhood saddened and concerned.

“How does that happen?” resident Karen Joyce told CBS2’s Scott Rapoport. “(Who) wants to kill a 70-year-old woman in her home?”

“She was in charge of the gardening. So I helped her with that, and she was very adamant that we had to use certain colors, like purple and yellow,” Stein said.

“She was very nice, she was a good neighbor to have. We would see her all the time, throwing bird seed for the birds,” Apicella added. “She loves my dog, so she’d always come around and pet my dog.”

Late Monday morning, detectives were seen emerging from Trott’s building, where there are surveillance cameras. Investigators are hoping they ultimately shed clues and light on this dark murder mystery.