(a) The chief judge of the district court in each county or a judge designated by him may order a grand jury summoned where authorized by law or required by the public interest.(b) The grand jury shall hear witnesses as may be determined by the grand jury and may find an indictment on the sworn testimony of one witness only, except in cases of perjury, when at least two witnesses to the same fact shall be necessary. An indictment may also be found upon the information of two of their own body.(c) The foreman of the grand jury may swear or affirm all witnesses who may come before the grand jury. Annotation Law reviews. For article, "State Grand Juries in Colorado: Understanding the Process and Attacking Indictments", see 34 Colo. Law. 63 (April 2005). Grand jury proceedings have been traditionally free of technical rules. People ex rel. Dunbar v. District Court, 179 Colo. 321, 500 P.2d 819 (1972). Applied in Thomas v. County Court, 198 Colo. 87, 596 P.2d 768 (1979); People v. District Court, 199 Colo. 398, 610 P.2d 490 (1980). .