"We have learnt that the victim's family wants a CBI (Central Bureau of Investigation) inquiry. We are deciding to hand over the investigation over to the CBI," Nitish Kumar told reporters in the state capital.
The chief minister also said that the investigation is being carried out with "highest diligence" and police will file a charge sheet at the earliest.
Assuring punishment to the perpetrators, Nitish Kumar said: "The person who has committed the crime will get the strictest punishment under law."
Nitish Kumar's remarks came after people across the state took out protests against the murder of the reporter.
Rajdeo Ranjan, Siwan bureau chief of Hindi newspaper Hindustan, which is part of the HT Media, was shot dead on Friday in a busy market near the Station Road in the district town.
Slamming the Bharatiya Janata Party (BJP) for terming the killing of the journalist and of a teenager in Gaya earlier as "return of jungle raj" in the state, Nitish Kumar said: "In the last elections those who wanted to get votes in the name of 'jungle raj' were defeated. Now they don't have any issues to target. That's why they are comparing everything to 'jungle raj'."
The chief minister asked people if they had suggestions on any other steps that can be taken. "I would like to ask people what else can be done, because if something else can be done, we would very much like to do it."