NEW YORK - A 70-year-old woman was found dead with a slashed throat in her apartment on the Upper West Side of Manhattan early Sunday, police said.

Investigators discovered the body of the woman, identified by police as Susan Trott, after receiving a call from her business partner, who had not heard from her in some time and asked authorities to check up on her, police said.

Police said there were no signs of forced entry, and that they were investigating the death as a murder.

Trott was found in her 14th-floor West End Avenue apartment, on a quiet stretch of red brick residential buildings a block away from Riverside Park.

Investigators gained entrance to the apartment just before 5 a.m. with help from a building superintendent. Once inside, they saw a trail of blood leading from the living room to the bedroom, where the body was found, clothed and lying on her back, police said. Police said they found no weapon.

Trott was a longtime copywriter, according to her personal website. She graduated from the Pratt Institute and had worked as a copywriter, as a freelancer and for a series of advertising agencies since at least the early 1980s, according to her LinkedIn profile.

Most recently, she was a creative partner at Code Modern, a marketing group based in New York and London, which she ran with a business partner, Eric Boscia.

Boscia said he was Trott's closest confidant and had worked with her for about 20 years, but would not say whether he was the one who called police. Boscia, who lives in London, said he last talked to Trott over the phone Wednesday.

"It was an uneventful conversation," Boscia said in a phone interview. "It's like my mother has died. She was the greatest, most generous, kindest person I've ever known."

Trott was born and raised in New York City, he said, and she was passionate about animals. She started her own rescue organization several years ago, he said.

"She did everything for dogs, pets, birds," Boscia said. "She would never hurt anyone."

Helen Stein, who lives on the 16th floor, also recalled Trott as a lover of dogs and one of the residents who helped with gardening at the building.

"I wouldn't say she was an easy person, but I was totally unaware that she had any enemies or anything like that," Stein, 72, said. "I just didn't really know her well."

Another neighbor said Trott lived alone.

"It's totally shocking to me because I never felt safer anywhere in my whole life than this place," Stein said.

Martha Wetterhall Thomas was a colleague of Trott's about four decades ago when they both worked for BBDO, an international advertising agency with its headquarters in New York City.

"She was fun and a little crazy, and she was very smart and great at what she did," Thomas, who lives in South Carolina, said in a phone interview. "She was somebody I looked up to."

Thomas said she had not talked to Trott in about 25 years, but she recalled an afternoon when a man stole Thomas' purse as the two friends were leaving a bank in the garment district during their lunch hour. Trott chased the thief down Sixth Avenue and managed to pin him down to the ground with help from garment workers in the area.

Police eventually apprehended the man, who was wielding a knife, and their lunch hour chase made the news.

"That was Sue in a nutshell. She was pretty gutsy," Thomas said. "She wasn't big, but she was a tornado kind of person."