A great grandmother hailed as a pillar of the community was severely beaten and stabbed to death while her flat was ransacked, detectives said.
Relatives have been left "devastated" by the murder of Irene Barrett, 88, police added.
Officers found Mrs Barrett, a retired secretary, with multiple knife wounds at her flat in Charlton, south-east London on Saturday.
Her friends spoke of their "disgust" at the "cowardly" attack and told how she knitted blankets for local babies and pets.
Speaking at the crime scene, Detective Chief Inspector Cliff Lyons said: "Irene was a well liked and well known member of the community. She was an active member of the residents' association.
"Her family are devastated at what has happened.
"Irene suffered multiple stab wounds and appears to have been severely beaten.
"Her flat was ransacked and some of her property was stolen, including jewellery and cash.
"This sort of crime is very unusual. We need the public to come forward to assist us."
A 34-year-old man, believed to be living in the same block of flats, remains in custody after being arrested on suspicion of murder.
