The SP said this while holding a press briefing around 12 noon today.
On October 8, Nur Mohammad Shah, 55, hailing from Kurigram, was hacked and strangled to death by unidentified miscreants at his house at Babor Alo gate area of the district town.
Mahsin Ali Shaha, brother of the victim filed a case with Kushtia Model Police Station on the following day.
After observing the footage of close circuit camera, police arrested Faruk Hossain, 35, a peon of the sub-registrar office on October 9 in this connection. Later, police arrested three other people by the names of Kamal Hossain, 34, Saidul Islam, 35 and Mashiul alam alias Babul, 40.
Following the confessional statements of the arrestees, police came to know that they killed Nur Mohammad for taking a good amount of money. As the killers could not get any money from his room they killed Nur Mohammad.
When briefing, the SP said Faruk, Saidul, Kamal, Mashiul along with another unidentified man plotted to kill Nur Mohammad 15 days before the murder and executed their plan on last Monday.
At first, Faruk went to the flat of Nur Mohammad where he used to live alone, for delivering his supper around 9:51 pm and when the door was opened the other killers swooped on the house and took Nur to his kitchen room after tying his mouth with a towel. They also tied up his hands, said the SP.
Later, they demanded money from him. As he refused to give the money, the criminals hacked him, leaving him dead on the spot.