N.Y. CPL Law § 450.40

§ 450.40 Appeal by people from trial order of dismissal.\n 1. An appeal by the people from a trial order of dismissal, as\nauthorized by subdivision two of section 450.20, may, as indicated by\nsection 290.10, be based either (a) upon the ground that the evidence\nadduced at the trial was legally sufficient to support the count or\ncounts of the accusatory instrument dismissed by the order, or (b) upon\nthe ground that, though not legally sufficient, such evidence would have\nbeen legally sufficient had the court not erroneously excluded\nadmissible evidence offered by the people.\n 2. If the appeal is based upon the ground specified in paragraph (b)\nof subdivision one, and if the appellate court determines that the\nevidence unsuccessfully offered by the people was improperly excluded,\nand if at the trial the people made on offer of proof with respect\nthereto pursuant to subdivision three of section 290.10, the appellate\ncourt, in making its determination whether the people's evidence would\nhave been legally sufficient had it not been for the improper exclusion,\nmust treat the excluded evidentiary matter as it is summarized in the\noffer of proof as evidence constituting a part of the people's case.\n