The probe into the killing of Asrar Mushtaq was conducted by the outgoing team of Srinagar range comprising Inspector General of Police (Kashmir range) B Srinivas, DIG Muneer Khan and SSP S Ahfadul Mujtaba, which was transferred on Tuesday.
They had been working on this case and certain leads were received from the mobile phone records of the deceased, which had been switched off after his death on July 3.
Giving details about the killing of the youth, which had brought Kashmir Valley to a standstill for three days after his body was recovered from Rainawari area on July 8, the police said there was a verbal duel between the deceased and his alleged killer Imran, a student himself, over a girl.
The arrest has put an end to the claims of separatists and second rung mainstream politicians that Mushtaq was allegedly killed in police custody.
Imran, who was arrested late on Tuesday night, has allegedly told the police during interrogation that Asrar had been making advances towards his girlfriend (whose identity has not been disclosed).
On the fateful evening, Imran and Asim decided to teach Mushtaq a lesson and he was invited to Imran's house in Soura to sort out the matter, the police said, adding that at his house, Imran allegedly banged the head of Mushtaq with weights used in gymnasium.
Mushtaq died on July 3 and the body was allegedly kept by Imran in his room only, the police said.
He later took his uncle's car from Karan Nagar on July 7 and dumped the body during night at Malkha in Rainawari area besides throwing his blood-soaked clothes at another place and mobile phone near Maulana Azad Road, the police claimed.
The alleged killer had hid Mushtaq's motorbike at Asim's house in Soura, who has also been arrested. Police claimed that they recovered the blood-stained clothes of Mushtaq and his motorcycle.
Soon after Mushtaq had gone missing, the police was accused by protesters of having picked him up for questioning.