Shocked neighbours have told of their fear and paid tribute to a "nice lady" found stabbed to death at her home in Muswell Hill.
The mother-of-one, named locally as Cathy Burke, was discovered at a house in a quiet street in north London.
Residents of Hill Road said they were disturbed to read reports that Ms Burke, believed to be in her 50s, was found tied up, but said police had not told them anything.
A post-mortem examination revealed the woman's provisional cause of death to be from stab injuries, Scotland Yard said.
Lesly Gregory, who knew the victim for around 10 years, said: "She was just lovely. She was such a nice lady."
She said she did not believe it was a random attack, adding: "Cathy wouldn't open the door to just anyone."
Ms Gregory, who has lived on the street for three decades, added tearfully: "We need to find Cathy's killer."
Ms Burke lived alone after her son moved out to go to university, and had previously worked for the local council, she said.
Another neighbour, Fenelle Archer Wright, described Ms Burke as "a very warm person, very friendly." She added: "It's scary that this has happened in our road."
Ms Burke moved to England from Galway as a teenager, neighbours said, and had lived in the street for around 20 years.
Police visited the house on Thursday evening after concerns were raised for her well-being.
Detectives, who are awaiting formal identification of the victim, said they are keeping an open mind about the motive. No-one has been arrested.
Tributes have been set in a hedge at the front of the terraced house, while a small police cordon remains in place at the entrance.