In this chapter, unless the context otherwise requires:

1. "Alternate grand jurors" means the additional grand jurors who are selected and sworn at the time of impanelment but who are not designated as permanent jurors until the presiding judge of the superior court or a designee has permanently excused a duly impanelled and sworn permanent grand juror.

2. "Grand jury" means a body of the required number of qualified persons who are duly convened and impanelled by the presiding judge of the superior court and who are sworn to inquire into public offenses that may be tried within the county, including corrupt or willful misconduct in office of public officials within the county.

3. "Indictment" means an accusatory statement that is in writing, that is presented by the grand jury to the superior court and that charges the commission of a public offense that may be tried within the county.