Police in Chittagong city arrested the alleged killer of Saoda, a first-year student of Barisal University, on Thursday.
The 18-year-old girl died on September 5 hours after being attacked by her former lover, Russell Mia, 20.
Tipped-off, police picked up Russell in Dhumpara area of Kalshi Dighir Par around 6:00pm, said Jahedul Islam, officer-in-charge of Bandar Police Station.
The official said in primary interrogation Russell admitted that he had knifed Saoda out of anger for her refusal to continue the affair, reports our Chittagong correspondent.
Russell told police he had fled to Dhaka immediately after stabbing the girl and went to Chittagong on Tuesday.
Jahedul said they had already informed the investigators about the arrest and will hand him over to them.
Meanwhile, Shahida Begum, mother of Saoda, filed a murder case with Kotwali Police Station in Barisal city accusing Russel and two to three others unknown persons. In the complaint, she blamed Russel for stalking her daughter but he did not mention if there had been any relationship between the two.
Russell, a second-year management student of the same university, had earlier been in love with her for at least one year, according to the campus.
Their relationship turned sour about a month ago when Russell proposed to the girl, upon which her parents rebuked him, said Prof Harunur Rashid, vice-chancellor of the university.
Following this, the girl had been trying to avoid him over the past one month. Infuriated, Russell hacked her with a knife in the back and neck around 8:30am on the campus, said teachers and students of the university.
The first-year accounting student was brought to the intensive care unit of Dhaka Medical College Hospital by air ambulance around 1:30pm where she succumbed to her injuries around 5:30pm.
The university authorities expelled Russell from the university following the incident.