Abrar Fahad had been called over from his room by his batchmates before he was murdered in the Sher-e-Bangla Hall of Bangladesh University of Engineering and Technology on Sunday night.
A resident of the dorm said after beating Abrar brutally the killers tried to give him medical care.
He said the police took no action at first after they had arrived at the hall and left the place saying they had "puja duty".
The student, who is from batch 16 and one of the fugitives accused of the murder, witnessed the events of the murder of Abrar Fahad and talked to The Business Standard on condition of anonymity. He, however, claimed he was not involved with the murder in any way.
"I was in my room when Abrar was summoned by his friends around 8pm on Sunday. There is CCTV footage of that part. I have seen the video. They are all from 17th batch," said the witness.
"I stayed in my room till 12:30am. I have no idea what happened during that time. I went to room 2011 later and saw two-three of his batchmates were massaging Abrar's body lying on a bed. He was still alive," he added.
"They then moved Abrar to room 2005. I also went to that room. Abrar's batchmates were giving him medical care. By that time Abrar's batchmates called the Chawkbazar police to hand him over saying that a Shibir activist had been found in the hall."
The witness said after the arrival of the police at 1am four students of batch 17 carried Abrar from the first floor to the ground floor.
But the police left the hall for the delay of the handover saying they had "puja duty".
By 2:30am many students gathered on the ground floor.
"Abrar may have died by then as no movement was visible," said the witness.
After some time, the physician of the university arrived at the spot and declared him dead, he added.