Over five months have passed after the gruesome murders of retired schoolteacher in Tangail Anil Kumar Das and his wife Kalpana Rani Das, but investigators could not make any significant headway in the case till now.
Due to the delay in investigation progress, victims' son Nirmol Kumar Das and expatriate daughter Anjana Das are becoming frustrated as police are yet to identify their parents' killers.
On July 27 last year, police found the couple dead, tied to a sack of bricks, at the bottom of a drainage well beside their house in Sadar upazila.
Following a case filed by deceased's son Nirmol with, police detained Anil's two stepbrothers -- Ratan Das and Swapan Soumitra -- for quizzing and later shown them arrested.
The duo were produced before a Tangail court on August 1 with a seven-day remand prayer.
After hearing on August 2 and 3, the court granted a three-day remand for them and the case was shifted to Detective Branch (DB) of police the same day.
The detectives, however, got no important information from the two that can resolve mystery of the murders.
Of the two arrestees, Swapan obtained bail from the court on December 28.
For quizzing, police also picked up six youths--Shahid Momen, Bhajan Sheel, Mofiz Uddin, Minju Miah, Khokon Bhuiyan and Dulu Miah--from Rasulpur village, suspecting their involvement in the murders.
The murders were committed in a pre-planned way, Officer-in-Charge of Tangail DB police Ashok Kumar Sinha said, adding that they are yet to identify the killers but hope to unearth the mystery soon.