A 75-year-old woman was found murdered at her Behala home when her son, daughter-in-law and granddaughter were away on Thursday morning, police said.

Sleuths suspect Subhra Ghosh Dastidar’s killer was in the house when a neighbour knocked on the door and called her family members after being told by the family’s help that no one was answering the doorbell.

The neighbour went home but returned a few minutes later and found the door of the Ghosh Dastidars’ two-storey house open, the police said.

The elderly woman, a cancer survivor, was found lying on the floor of her first-floor bedroom with her face down.

Subhra, a resident of Sisir Bagan Road, off the Behala tram depot, was strangulated with a blouse and smothered with one of her saris that had recently come from an ironer, an officer said.

“Her gold chain and bangle were missing. We suspect she was murdered for gain,” the officer said.

“It could be that one or more men had tied her hands with her shoulder and muffled her voice with a sari while carrying out a robbery. But as the doorbell rang and people started gathering outside the house, they might have panicked and killer her. It is suspected the victim had opened the door to let in someone she knew.”

Subhra’s son Subhabrata and granddaughter had left home for work and school in the morning. Daughter-in-law Sangita, a state government employee, left for work a little later around 10.30am.

The family’s next-door neighbour called up Sangita around 12.25pm, telling her that her mother-in-law was not opening the door.

“Since my mother-in-law was a cancer survivor and often kept unwell, we had requested our neighbour to be a little attentive when she was alone. Today, the neighbour intervened when my mother-in-law failed to respond to the doorbell and alerted me over the phone,” Sangita said.

Joint commissioner (crime) Murlidhar Sharma said: “When the neighbour had first knocked on the door, it was locked from inside. She (neighbour) called up the daughter-in-law and walked towards her home while talking. When she returned after a few minutes, she found the door open.”

The drawers and the cupboards were open and the belongings on the bed were scattered when the police reached the spot. A sling bag was found on the floor of the adjoining room with some papers strewn around.

The house, in a narrow bylane off Diamond Harbour Road, was painted recently and the family was planning to hire a carpenter to make some furniture. “The labourer who had painted the house brought a carpenter on Wednesday,” an officer of the homicide department said.

In April, 75-year-old Shyamali Ghosh had been killed at her Jodhpur Park home allegedly by the caretaker and the gardener of the building where she lived.

Incidents such as these expose how vulnerable elderly people in the city are.