N.Y. Real Property Actions & Proceedings Law § 1112

§ 1112. When life tenant deemed dead and petitioner let into\npossession. If it appears from the referee's report, or upon the\nhearing before the court, that the person upon whose life the prior\nestate depends was not produced and if the party required to produce\nhim, or to prove his existence has not proved to the satisfaction of the\ncourt that he is living, a final order must be made, declaring that he\nis presumed to be dead, for the purpose of the proceedings, and\ndirecting that the petitioner be forthwith let into possession of the\nreal property, as if that person was actually dead.\n