Arizona Revised Statutes Title 21. Juries § 21-407. Duties of grand jurors

A. The grand jurors shall inquire into every offense which may be tried within the county which is presented to them by the county attorney or other prosecuting officer at the request of the county attorney, or by the attorney general as a special prosecutor appointed by the presiding judge of the superior court for the purpose of proceedings under § 21-408, subsection B, or § 38-344, and shall have access to all jails, public institutions, and public records.

B. If a grand juror knows of or has reason to believe that an offense which may be tried within the county has been committed he shall report such knowledge or belief to the county attorney or to the presiding judge of the superior court.  If an investigation of such alleged offense is undertaken under a charge to the grand jury as provided in subsection B of § 21-409, the grand juror may be sworn as a witness.