According to the Fairfax Times, a preliminary hearing was held on February 23. Friends and family of the victim, Mazhar Nazir, attended the hearing.
The Fairfax Times did not provide details of what occurred at the hearing
The Fairfax Times reported that the case was forwarded to the grand jury (term date: March 17, 2009).
The Virginia Courts webpage, explains (under Procedure) what a preliminary hearing is.
A preliminary hearing is then held in district court to determine if there is probable cause to believe the accused has committed the crime charged. If probable cause is found, the case is certified (sent) to the grand jury.
The grand jury is a body which determines whether there is probable cause to believe that the accused committed a crime and should have a trial to determine innocence or guilt.
The Virginia Courts provide a handbook for grand jurors.
The Virginia Criminal procedure law is here.