"In many—if not all—U.S. jurisdictions that use grand juries, prosecutors often have a choice between seeking an indictment from a grand jury and filing a charging document directly with the court. Such a document is usually called an information, accusation, or complaint, to distinguish it from a grand-jury indictment. To protect the suspect's due-process rights in felony cases (where the suspect's interest in liberty is at stake), there is usually a preliminary hearing, at which a judge determines whether there was probable cause to arrest the suspect who is in custody. If the judge finds such probable cause, he or she binds, or holds over, the suspect for trial." wiki on indictment in the US
A question has arisen of whether or not a grand jury in the District of Columbia will indict officials of the government who were allies of the Obama Administration. DC is a heavily Democratic place.
This wiki makes it clear that a "true bill" indictment from a grand jury is not necessary for prosecution. Such an indictment is merely customary in most cases from respect for our English Common Law heritage.
IMO it is doubtful that a petit jury in DC would convict during actual trials.
Alternatively, this difficulty as well as the one with the grand jury could be overcome by changing the venue of the proceeding to the Eastern Federal Court District for Virginia where IMO both an indictment and conviction would be very likely. The demographics and politics are much different on this side of the Potomac in a district that covers the whole eastern half of the Commonwealth of Virginia. pl