Dhaka Metropolitan Magistrate Tofazzal Hossain recorded the confessional statement of Robein, expelled organising secretary of Buet unit of Bangladesh Chhatra League (BCL).
The court also sent him to jail.
On October 8, Robein along with nine other BCL leaders and activists was put on a five-day remand over the gruesome murder.
Abrar, 21, a second-year student of electrical and electronic engineering department of Buet, was beaten to death BCL leaders at Sher-e-Bangla hall of the university.
He was found dead on the staircase of the dormitory in the early hours of October 7.
Victim’s father Barkatullah filed a case against 19 people with Chawakbazar Police Station in this regard.
A total of 19 people, including 15 FIR-named accused, have so far been arrested over the murder.