After hearing, examining and investigating the evidence before it, a grand jury may, in its discretion, issue an indictment against a principal. A grand jury shall find an indictment only when from all the evidence at least three-fourths of the jurors are convinced that there is probable cause to believe a principal is guilty of a criminal offense. When an indictment is found by a grand jury the foreman or acting foreman shall present it to the court.

[1971 ex.s. c 67 § 15.]