Nev. Rev. Stat. § 172.047
A district judge may impanel a grand jury to inquire into a specific limited matter among those set forth in NRS 172.175. In that case, the judge shall charge the grand jury as to its limited duties and give it such information as the judge deems necessary. A grand jury that is impaneled for a specific limited purpose shall not inquire into matters not related to that purpose. A grand jury impaneled for a specific limited purpose may be discharged after the grand jury completes its investigation and submits its report. If the grand jury has not completed its investigation and submitted its report within 1 year after it was impaneled, it shall, in a closed hearing, show cause to the judge why it should not be discharged. If the judge determines that it is in the public interest for the grand jury to continue its investigation, the grand jury may continue for a period which does not exceed 1 year.
NRS 172.047