A court in Gaya on Monday sent Teni Yadav, the friend of JD (U) MLC Manorama Devi's son Rocky Yadav, to judicial custody for 14 days.
Yadav, who was present during the murder of Aditya Sachdeva, surrendered before the court earlier on Monday. today.
The Bihar Police had arrested Rocky, the main accused in the murder case, last Tuesday.
The police later arrested Rocky's father Bindi Yadav and their bodyguard in connection with the case.
Manorama Devi was also detained for hours by the police last Monday for interrogation.
Rakesh Ranjan Yadav alias Rocky is accused of killing Class XII student Aditya Sachdeva after an argument with the youth for overtaking his vehicle on May 7.