A local Awami League leader had allegedly plotted the murder of Jahidul Islam Tipu in Dhaka's Shahjahanpur, according to the Rapid Action Battalion (RAB).
The elite police unit identified Omar Farooq, general secretary of the ruling party's Dhaka South Ward-10 unit, as the mastermind behind the shooting which also resulted in the death of bystander Samia Afnan Jamal Prity on March 24, reports bdnews24.com.
Farooq was aiming to assert his dominance by taking out Tipu, RAB spokesman Khandaker Al-Moin said at a media briefing on Saturday.
He was arrested along with three other suspects -- Nasir Uddin, Abu Saleh Sikder and Morshedul Alam -- on Friday.
Earlier, Dhaka Metropolitan Police's Detective Branch (DB) arrested Masum Mohammad Akash and Arfan Ullah Damal in connection with the case. They have since been placed on remand.
According to the DB, it was Akash who had shot Tipu.
Tipu, a former general secretary of the party’s Motijheel unit in Dhaka, was gunned down under a flyover outside Manama Bhaban in the Amtala area.
A gunman wearing a helmet on a motorcycle pulled up next to Tipu’s microbus and opened fire.
Prity, a student of Begum Badrunnesa Government Girls’ College, was also killed by a stray bullet, while Tipu’s chauffeur 'Munna' was injured.
Within moments of pulling the trigger, the assailant jumped over a divider, hopped on a motorcycle waiting on the other side of the road and fled.
Tipu’s wife Farzana Islam Dolly, a local councillor of the city corporation, subsequently filed a case against unidentified suspects with the Shahjahanpur Police Station on Mar 25.
She alleged that Tipu had received a death threat over the phone some days ago.
Tipu was accused and arrested in a decade-long case over the 2013 murder of Jubo League leader Reazul Haque Khan Milky. But he was later acquitted in the case, according to some of his colleagues.