Iowa Code § 633.519

If a jury in an inquiry regarding the disappearance of an individual renders a unanimous verdict in writing that sufficient evidence has been presented to them from which it fairly may be presumed that the missing person has met death, and if the judge or magistrate concurs in the verdict, then, after a period of six months has elapsed, the person shall be presumed to be dead and the judge or magistrate shall enter an order to that effect. However, in cases where there is clear and convincing evidence of the presumed death, the judge or magistrate may enter the order prior to the elapsing of the six-month period.