N.Y. PEN Law § 210.20

§ 210.20 Perjury; pleading and proof where inconsistent statements\n involved.\n Where a person has made two statements under oath which are\ninconsistent to the degree that one of them is necessarily false, where\nthe circumstances are such that each statement, if false, is\nperjuriously so, and where each statement was made within the\njurisdiction of this state and within the period of the statute of\nlimitations for the crime charged, the inability of the people to\nestablish specifically which of the two statements is the false one does\nnot preclude a prosecution for perjury, and such prosecution may be\nconducted as follows:\n 1. The indictment or information may set forth the two statements and,\nwithout designating either, charge that one of them is false and\nperjuriously made.\n 2. The falsity of one or the other of the two statements may be\nestablished by proof or a showing of their irreconcilable inconsistency.\n 3. The highest degree of perjury of which the defendant may be\nconvicted is determined by hypothetically assuming each statement to be\nfalse and perjurious. If under such circumstances perjury of the same\ndegree would be established by the making of each statement, the\ndefendant may be convicted of that degree at most. If perjury of\ndifferent degrees would be established by the making of the two\nstatements, the defendant may be convicted of the lesser degree at most.\n