Iowa Code § 633.518
If a petition is presented by an interested person to a district judge or magistrate alleging that a designated person has disappeared and after a diligent search cannot be found, and if it appears to the satisfaction of the judge or magistrate that the circumstances surrounding the disappearance afford reasonable grounds for the belief that the person has suffered death from accidental or other violent means, the judge or magistrate shall summon and impanel a jury of six qualified persons to inquire into the facts surrounding and the presumption to be raised from the disappearance. If no one submits a petition within forty days of the reported disappearance, a judge or magistrate may submit the petition from personal knowledge of the case.
Iowa Code § 633.518
2002 Acts, ch 1108, §28