Ohio Rev. Code § 2121.01: Presumption of death.

(A) Except as provided in division (B) of this section, a presumption of the death of a person arises upon either of the following:

(1) When the person has disappeared and been continuously absent from the person's place of last domicile for a five-year period without being heard from during the period;

(2) When the person has disappeared and been continuously absent from the person's place of last domicile without being heard from and was at the beginning of the person's absence exposed to a specific peril of death, even though the absence has continued for less than a five-year period.

(B) When a person who is on active duty in the armed services of the United States has been officially determined to be absent in a status of "missing" or "missing in action," a presumption of death arises when the head of the federal department concerned has made a finding of death pursuant to the "Federal Missing Persons Act," 80 Stat. 625 (1966), 37 U.S.C.A. 551, as amended and hereafter amended.