If a person leaves his domicile without a known intention of changing it, and does not return or is not heard from for seven years from the time of his so leaving, he shall be presumed to be dead in any case where his death is in question, unless proof is made that he was alive within that time.
D.C. Code § 14-701
Presumption of death
Dec. 23, 1963, 77 Stat. 522, Pub
Official source: D.C. Law Library (Council of the District of Columbia). Reproduced from public-domain District of Columbia statutes; confirm against the official source for the current text. Not legal advice.