Three persons, including an elderly woman, were found murdered inside a house in West Burdwan's Panagarh on Friday afternoon.
Police said the deceased had been identified as Sita Devi, 70, her grandson Sonu Biswakarma, 21, and house owner Dhananjay Biswakarma's daughter Shimran Biswakarma, 23.
The police said Sonu's body was found lying in the courtyard of the single-storey house, while the bodies of Shimran and Sita were found in a room.
"We found injury marks on the back of Sonu's head. We found strangulation marks on the neck of the two other bodies," said ACP Suman Jaiswal.
The police said house owner Dhananjay and his wife left home on Monday to visit his pregnant elder daughter in Guwahati. One of the neighbours told the police that she had seen a person go inside the house wearing a helmet in the morning.