Fardin’s father Kazi Nur Uddin had filed a general diary at Rampura police station after Fardin went missing on 4 November.

After the police found his body on 7 November, they tried to track his whereabouts in the hours before his death by tracking his cellphone position.

The investigators found that at around 10:00 pm on 4 November, Fardin was in Rampura, dropping one of his friends home. He was inside Rampura phone tower’s network till 10:09 pm.

At 10:35 pm, he was inside the Keraniganj tower’s network, at 10:53 pm inside the Babubazar’s network, at 11:09 pm at Johnson Road and at 2:01 am inside the Bibir Bagicha tower’s network in Jatrabari, Dhaka.

The final position of his cellphone was in Chanpara at 2:34 am. After that, his phone was switched off.

According to his family, Fardin had an exam on 5 November. He left his home in Konapara, Demra at noon on 4 November, telling his family he would stay the night at a domitory in BUET. The investigators still don’t know why he didn’t go to the BUET campus that night.

The RAB officials, who have been conducting the investigation, said they are almost certain that in the last 33 minutes before the cellphone was switched off, Fardin was held hostage by a criminal gang in Chanpara.

According to the RAB officials, some 10-11 people were involved in the murder.

Fardin’s cellphone position between 2:01 am and 2:34 am on 5 November was near that of two of the suspects’. One of them is a bus driver and the other is his assistant.

The investigators think that those two took Fardin to Chanpara. But did Fardin fall into their trap, or was he forcefully taken there, the investigators are yet to find out.

Sources at RAB said, the two suspected transport workers work in Dhaka’s Abdullapur to Narayanganj road route. At midnight, they would take passengers on the bus and then rob their money and other valuable items. Sometimes, they would take the passengers to Chanpara.

Some 14-15 people at Chanpara are also part of this criminal gang. They are involved in selling drugs, looting people and other such crimes.

Director of RAB’s legal and media wing commander Khandaker Al Moin told Prothom Alo, “After technology-based investigation and analysing intelligence information, we are almost certain that Fardin’s murder took place at Chanpara or in its vicinity. Raihan, the leader of a crime gang in Chanpara, and his associates are involved with the murder. After arresting those involved we will be certain about the motive behind the murder.”

Earlier, on 7 November, body of BUET’s civil engineering department student, Fardin, was recovered from Shitalakshya river in Narayanganj.

Fardin’s father filed a case at Rampura police station accusing his son’s friend Ayatullah Bushra. The police later arrested Bushra in this connection.