An indictment is a written accusation of crime made by a grand jury. It must be concurred in by not less than nine of the grand jurors, indorsed "a true bill," and the indorsement must be signed by the foreman. Indictments shall be returned into the district court in open court; but when an indictment has been returned for an offense which is within the trial jurisdiction of another court in the parish, the indictment may be transferred to that court.