The grand jury must inquire into all public offenses committed or triable within the county, and present them to the court, either by presentment or by indictment.

[(19-1101) Cr. Prac. 1864, sec. 201, p. 237; R.S., R.C., & C.L., sec. 7630; C.S., sec. 8789; I.C.A., sec. 19-1001.]