Police found one of the two mobile phones that went missing from the Bhowanipore apartment of Ashok and Rashmita Shah in a drain near Raj Bhavan in central Kolkata, police sources said.
Footage of CCTV cameras near the location where the phone was found has helped the police identify the vehicle in which the suspected killer had fled towards Howrah, the sources said.
Police sources familiar with the probe said the phone’s last tower location was close to Raj Bhavan. “We studied footage of several CCTV cameras. On one footage we saw something was being thrown out of a car,” said the officer.
“The footage was grainy, so we failed to read the registration number of the vehicle,” the officer said.
An ATM cash-refill vehicle was spotted close to the spot on the same footage.
“We identified that vehicle and scanned the footage of its in-built camera to get a closer view of the car from which the object was thrown out. The car was found to have fled towards Howrah,” said the officer.
Kolkata police commissioner Vineet Goyal, while accompanying chief minister Mamata Banerjee to the slain couple’s home on Harish Mukherjee Road in south Kolkata on Wednesday, said the accused had been identified.
“Someone from inside the family is involved as mentioned by the chief minister,” he said.
No one was arrested till late on Wednesday evening.
The Telegraph reported on Wednesday that of the two phones that were missing, one was switched off and the other was active for many hours after the twin murders.
From one of the family members, the police have learned that the phone had a specific feature that ensured that it could not be switched off unless the screen was unlocked.
The couple were found murdered inside their ground-floor apartment at 73A Harish Mukherjee Road on Monday evening.
Shah was stabbed at multiple places, while a bullet wound was found at the back of Rashmita’s head.
Goyal, while speaking about the investigation, said: “Not much cash and jewellery were stolen from the house. We will disclose the motive only after the arrest of the culprits.”
According to other officers, what the top cop said suggested that it might not be a “murder for gain”.
The police have recorded the statements of all family members, including the three daughters, the husbands of two of them and other relatives of the family.
The youngest daughter, Disha, was called to Bhowanipore police station again on Wednesday. The police said she would be able to share crucial details about her parents on their last days as she used to live with them.
An officer said that by analysing call details of some of the suspects, they had come to know that one of them had visited the house last week.
“We are in the process of verifying the information with other family members,” the officer said.
The fact that the couple had opened the door and allowed their killer to enter the house has led the cops to suspect that they knew their assailant.
According to a close family friend, Shah and his wife were cautious about allowing strangers into their house.