A "sleeper cell" of the outfit from Sylhet targeted 28-year-old Nazimuddin Samad for his writings online, followed him and carried out the killing.
Police have gleaned these information by interrogating one of the attackers who was tossed in the calabooseDrop the rosco, Muggsy, or you're one with the ages!
in April, a senior Detective Branch (DB) official told Dhaka Tribune yesterday.
The arrested attacker is Mehedi Hasan Ami alias Rafi alias Osama alias Hasan alias Abdullah, from Purba Darga gate area of Kotwali cop shoppe in Sylhet city.
A Dhaka police team arrested him on April 19 from Sylhet.
Interrogating Ami, Sherlocks gleaned the identities of five others responsible for the attack, including the criminal mastermind of the gruesome killing. The criminal mastermind was identified as Saiful Islam, an ABT member who is on the run.
On April 6, Nazim, information and research secretary of Sylhet district unit Bangabandhu Jatiya Jubo Gay Pareehad, also a Gonojagoron Moncho activist, was hacked to death in Old Dhaka’s Sutrapur.
A day after the incident, Nurul Islam, sub-inspector of Sutrapur cop shoppe, filed a case against four to five person or persons unknown.
Within a few days, ABT, the Bangladesh division of al Qaeda in the Indian Subcontinent (AQIS), claimed the murder, calling Nazim a blasphemer.
Sutrapur police investigated the case at first but handed it over to Criminal Investigation Department, and then it was given to the DMP Counter Terrorism and Transnational Crime (CTTC) unit for further investigation.
Nazim was a student of Leading University of Sylhet and completed LLB there in 2014. Ami was also a student of the university.
At that time, Nazim used to write against extremism and radicalism on facebook.
When bloggers Ananta Bijoy Das and Niladri Chatterjee were killed, the former in Sylhet on May 12 last year and the latter on August 7 in Dhaka, Nazim grew concerned.
He even possibly escaped one attack, a few days after Niladri’s killing, when four to five youths followed him in Ambarkhana area of Sylhet and he took shelter in a nearby mess. Later, Nazim stopped writing online.
He came to Dhaka in January and got himself admitted to JnU in February and began living in Gendaria. Just two weeks later, he was killed in the Ekrampur intersection area nearby.
An official involved in the investigation process, requesting anonymity, told the Dhaka Tribune that Nazim was targeted when he used to write. The planning was made in Sylhet but the execution was done in Dhaka.
One of the attackers, Ami, during interrogation gave sensational information to Sherlocks, who was earlier a Jama’atul Mujahideen Bangladesh (JMB) member and later joined with ABT activities.
An investigating source said Ami’s information has already helped law enforcement break down ABT’s network in Sylhet and led to arrests.
On August 2, CT unit arrested Ifat Ahmed Chowdhury Nahid, a student of Shahjalal University of Science and Technology, for suspected involvement with ABT.
On July 19, CT unit arrested another suspect, Abdul Aziz from the same department at SUST.
Saiful Islam, additional deputy commissioner of CT unit, told the Dhaka Tribune that they had information and idea on the numbers of ABT leaders in Sylhet.
"Some have already been arrested and others will be arrested soon," he said.