It is the fourth arrest in the case after main accused Rakesh Ranjan Yadav alias Rocky, his father Bindi Yadav and bodyguard Rajesh Kumar.
The Janata Dal-United on Sunday condemned the road rage incident in which party Member of Legislative Council Manorama Devi's son shot dead a youth and assured that appropriate action would be taken against him as per the law.
This come a day after she surrendered in a case lodged against her under the Excise Act after liqour bottles were recovered from her residence last week.
Rocky Yadav was found guilty of IPC sections 302 (murder), 323 (voluntarily causing hurt) and 427 (mischief causing damage) and section 27 of the Arms Act.
Rocky's father Bindeshwari Prasad was sentenced to five years' imprisonment for sheltering their son who was on the run after the killing.
M I Khan traces his story and finds that he was a virtual nobody 25 years ago.
Chhatrapati Yadav, the MLA from Khagaria Sadar, has shot off a letter to Congress high command, demanding that he be considered, by virtue of his caste, for a berth in the new cabinet headed by Chief Minister Nitish Kumar.
The two were being taken to Gaya central jail for interrogation, Magadh Zone Deputy Inspector General Saurabh Kumar said.