D.C. Code § 42-111

Deeds and other instruments affecting land situate in the District of Columbia may be acknowledged in the islands of Guam and Samoa or in the Canal Zone before any notary public or judge, appointed therein by proper authority, or by any officer therein who has ex officio the powers of a notary public; provided, that the certificate by such notary in Guam, Samoa, or the Canal Zone, as the case may be, shall be accompanied by the certificate of the governor or acting governor of such place to the effect that the notary taking said acknowledgment was in fact the officer he purported to be; and any deeds or other instruments affecting lands so situate, so acknowledged since the 1st day of January, 1905, and accompanied by such certificate shall have the same effect as such deeds or other instruments hereafter so acknowledged and certified.