A notice of supervening indictment means that a grand jury has found probable cause related to a felony charge, according to attorney Aaron M. Black. As noted by the Judicial Branch of Maricopa County, once a supervening indictment is granted, a defendant's case goes directly to arraignment without a preliminary hearing.
According to attorney Alfred McDonald, the legal system requires a certain number of grand jury members to vote for probable cause before a supervening indictment is issued. The formal indictment notice document can also include an arraignment date. In essence, the grand jury is ordering a person to appear in court on a certain date to be officially arraigned on the charges. Defendants who are not in custody receive the notice via mail. Defendants already in custody are given the notice by a jail official. After receiving a supervening indictment notice, a defendant must appear in court at the appointed date and time. The court can issue a warrant for arrest if a person fails to show in court, notes McDonald.
The prosecution brings evidence before the grand jury, which then has the power to look over evidence and interrogate witnesses and others, notes FindLaw. Prosecutors commonly use a grand jury to test the strength of a case.