Neb. Rev. Stat. § 29-1410.01

Any person may approach the prosecuting attorney or the grand jury and request to testify or retestify in an inquiry before a grand jury or to appear before a grand jury. The prosecuting attorney or the grand jury shall keep a record of all denials of such requests to that prosecuting attorney or grand jury, including the reasons for not allowing such person to testify or appear. If the person making such request is dissatisfied with the decision of the prosecuting attorney or the grand jury, such person may petition the court for hearing on the denial by the prosecuting attorney or the grand jury. If the court grants the hearing, then the court may permit the person to testify or appear before the grand jury if the court finds that such testimony or appearance would serve the interests of justice.