The trend of acquainted persons’ involvement in murders has sent police into a tizzy.

With the men in khaki yet to make headway in the killing of Krishna Sinha (50), whose body was found at her Kankerbagh residence on Monday afternoon, the police think that someone the lady had known must have killed her. “It appears that the murderer to be someone who knew the family quite well,” Patna city superintendent of police Jayant Kant told The Telegraph.

Police sources said that they had recovered dishes with some snacks and teacups at one of the rooms. Some local residents later told the police that they had seen two motorcycle-borne youths entering the house in the afternoon.

“The killer or killers knew the lady well and it seems that she had served him or them with tea and snacks. The door was also locked from inside. The lady wouldn’t have even imagined that something like this would happen to her. Those who killed her had a well-laid plan and executed it calmly as there are no signs of any ruckus or struggle in the house. We are also trying to find out whether there is any family feud behind the murder,” a police officer said.

Interestingly, this is not the first time where an insider’s role is suspected in a murder. In the case of the killing of Pankaj alias Pappu Yadav, which the police claimed to have solved, the main conspirator turned out to be Pankaj’s close friend.

In case of the “mysterious death” of lawyer Sangeeta Sinha in her Budh Marg flat on June 20, the police have a strong suspicion of a close person. “Earlier, it has been proved that the woman used to rent out her flat for alleged immoral activities and she was in touch with a lot of girls and pimps as a result. One of the girls, in her statement at court, said that Sangeeta had once told that she feared for her life from two persons close to her. Though the investigations are still on, an insider hand cannot be ruled out for sure,” said an officer at Kotwali police station.

In the incident of killings of an elderly couple — Ashok Malviya and Savitri Devi — at their Sahpur home, the police had picked up those involved and all of them were known to the couple. Police sources said solving of such cases took time and a toll on them.

“Solving a case in which professional killers have been given the task is easy. The police have got a background of a lot of criminals who can be involved and works according to a standard operating procedure. However, when it comes to insiders, only after a thorough investigation and scanning that leads come up and the police work on them,” a police officer said.