In the investigation of a charge for the purpose of presenting an indictment or accusation, the grand jury may receive the written testimony of the witnesses taken in a preliminary examination of the same charge, and also the sworn testimony prepared by the district attorney without bringing those witnesses before them, and may hear evidence given by witnesses produced and sworn before them, and may also receive legal documentary evidence. Each indictment or accusation shall be voted on separately by the grand jury.
Okla. Stat. tit. 22, § 333