Bangladesh Arrests Prime Suspect in American Blogger Murder

Nearly four days after the gruesome murder of atheist American blogger Avijit Roy in the Bangladeshi capital Dhaka, the country's elite paramilitary police force today arrested a prime suspect in Thursday night's brutal killing. The Rapid Action Battalion (RAB) detained Farabi Shafiur Rahman at 5.30am on Monday morning as he was about to board a bus to the city of Chittagong, Commander Mufti Mahmud Khan, director of RAB's legal and media wing, told VICE News.

At a press conference around noon, Khan said: "During primary interrogations, Rahman has admitted of posting threats online against Avijit Roy." RAB sources also mentioned that during interrogations, Rahman claimed that he supports Roy's killing, but denied any direct involvement.

According to Bangladeshi bloggers, Rahman threatened Rokomari.com, an online store, to stop selling books written by Roy. Imran H. Sarker, the head of a Bangladeshi bloggers' association, told VICE News: "It was Rahman who had issued a death threat to Avijit Roy on February 9, 2014, through a Facebook status."

Sarker added that Rahman was instrumental in promoting the murder of another atheist blogger, Rajib Haider, who was killed on February 15, 2013. "Two days later, Rahman had threatened that any imam who prays at Haider's namaz-e-janaja [muslim funeral prayer] will also be killed," he said.

In another Facebook status, Rahman wrote: "To me atheists are nothing but insects, and it is best that insects should die." On February 24, 2013, police arrested Rahman at Chittagong University. He spent six months in jail, after which he secured bail. Rahman hails from Brahmanbaria in east-central Bangladesh and he dropped out of a physics course at Chittagong University.

RAB sources stated that Rahman will be handed over to the Bangladeshi police detective branch, the main investigators in the murder case.

Roy, an Bangladeshi-American blogger and author who lived in the US, came to Bangladesh on February 16 with his wife Rafida Ahmed Banna for two promotional events for his books at Dhaka's annual book fair. He was also the founder of Mukto-Mona, a blog that promotes liberal secular writing.

On Thursday night, Roy and Banna were attacked near Dhaka University by two men with cleavers. Although the couple were rushed to a nearby hospital, Roy succumbed to his injuries there. Banna was seriously injured.

Related: Protesters take to the streets over atheist American blogger hacked to death in Dhaka. Read more here.

While focusing on the threats made by Rahman to Roy in the past, the police are also investigating the involvement of the organization known as the Ansarullah Bangla Team. On Friday, the Islamic militant group appeared to claim responsibility for the attack.

Just hours after the event, a Twitter account titled Ansar Bangla-7 celebrated the murder and described it as an "achievement". In a series of tweets, the account described Roy's murder as a punishment for his "crime against Islam." The account has been deactivated since February 28.

VICE News has learnt that the Bangladeshi police are also looking to assistance from the US Federal Bureau of Investigations (FBI) in solving the case. On Friday, the FBI offered to assist in the investigation.

In an official statement at the weekend, the US Embassy in Dhaka stated, "Avijit was a journalist, a humanist, a husband, and a friend, and we extend our condolences to his family and friends. He was taken from us in a shocking act of violence.

"This was not just an attack against a person, but a cowardly assault on the universal principles enshrined in Bangladesh's constitution and the country's proud tradition of free intellectual and religious discourse."