Another relative of the slain police officer said Karim's relations with his brother’s children were bitter.
The 60-year-old was murdered at his Dhaka residence at Rampura on Thursday.
He had retired from police’s Criminal Investigation Department (CID) in 2007 as an ASP.
DMP Motijheel zone Additional Deputy Commissioner (ADC) Mehedi Hasan said several assailants had entered Karim’s residence on the second floor of a five-storey building at Wapda Road at around 10am and shot him.
Karim owned the building and lived there with his family.
His brother-in-law Touhid Kashem Khan Prince said Karim’s wife, Swapna Karim, had seen a youth with firearms in the staircase when she was leaving for her daughter’s home at Gulshan.
Swapna panicked and asked him who he was looking for. Then the youth forced her to get inside the house and called two of his associates up on the second floor.
Prince said they had locked Swapna in a room and fled after shooting Karim.
Doctors at the Dhaka Medical College and Hospital (DMCH) declared the ASP dead after his driver and tenants of the building rushed him there, police outpost Inspector Md Mozammel Hoque told bdnews24.com.
Motijheel police’s Deputy Commissioner Md Ashrafuzzman said the motive behind the murder was still unclear.
“CID and police detectives are working on the matter,” he said.
However, Karim’s daughter Farjana Karim Badhon alleged that her father might be killed over a land dispute.
She said her father was involved in a dispute with his brother’s family over a house at their ancestral home at Ramkrishnadi village in Munshiganj’s Sirajdikhan Upazila.
Asked about the motives behind her father’s murder, Badhon said, “Catch them. Then you will know the reason".
A nephew of Karim, Sajidur Rahman said Badhon’s family was not having the best of relationship with the two sons of the brother of the slain police official- ‘Shanto’ and ‘Rubel’.
They are the sons of Bazlur Karim.
Asked about the reason behind the deterioration in relationship, Rahman said, “The boys are derailed and did not study at all. That’s why they had bad relationship with the uncles.”
He said Karim used to run an institution in his village named Ramkrishnadi Kaomi Madrasa.
“My uncle (Karim) appeared on a television talk-show some days ago. I have heard he was threatened several times after that.” He, however, could not elaborate.
Neighbours of Badhon are also clueless about who could be the murderers.
Apart from Swapna and Karim, a household worker and a minor boy were also in the house at the time of murder. The boy said he heard three gunshots, Prince said. But police said they found only a bullet injury in the head.
There is a garage and a house for the driver on a three-katha plot in front of the house. The driver ‘Liton’ lives in that house.
Saidur Rahman, a tenant at the building for the last 10 years, said: “I didn’t even hear any gunshots.”
“Suddenly in the morning, Liton came and started to knock at my door. And then he said someone has shot the landowner.”
He said he took Karim to the hospital with his neighbours later.
Mohammad Shakil, owner of a nearby confectionary store, said he was working at his shop when the murder took place but did not see any suspects.
Top police officials rushed to see him at DMCH as the news of the attack on Karim was out.
Special Superintendent of CID Abdul Kahar Akhand told bdnews24.com that Karim investigated several sensational cases in the 1980s.