How much time does a prosecutor to present a case to a grand jury?

My roommate is sitting in jail, and the police were trying to charge him with 2 felonious abductions, and 1 misdemeanor domestic violence. He's been sitting for 12 days now. We all expected (including his lawyer) for the prosecutor to present the case to the grand jury yesterday, but they haven't done it yet. How much longer can they legally put it off?