A joint Special Investigation Team (SIT) and Siwan district police arrested the five shooters.
Police suspect criminal Laddan Miyan, a close aide of former RJD MP Shahabuddin, carried out the contract killing.
The names of the apprehended men are Rohit, Vijay, Rajesh, Kumar, Sonu Gupta. The motive behind the killing hasn't been disclosed by the police so far. Police have seized three bikes and some ammunitions from them.
Rajdev’s kins have demanded security in view of threats from the convicted don Shahabuddin. His widow, Asha Devi, had said her husband had received threats from Upendra Singh, a contractor considered to be close to the jailed don.
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The special investigation team (SIT) constituted to probe Rajdev's murder had earlier interrogated 15 suspects, of whom six of are believed to be Shahabuddin's men.
Journalists had hit the streets in Bihar to protest the killing of Rajdev Ranjan, Siwan district bureau head of prominent vernacular newspaper 'Hindustan'. The state government had recommended a CBI probe into the killing.
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Following the incident, Bihar government was heavily criticised by the opposition parties alleging return of 'jungle raj' in the state. CM Nitish Kumar responded to it by saying it was "a pre-decided tune which they play on case to case basis". Kumar added that he did not need any "certificate" from anybody on "rule of law". He said the rule of law was prevailing in Bihar and would continue in future too.