N.Y. C.P.L.R. 4513

§ 4513. Competency of person convicted of crime. A person who has been\nconvicted of a crime is a competent witness; but the conviction may be\nproved, for the purpose of affecting the weight of his testimony, either\nby cross-examination, upon which he shall be required to answer any\nrelevant question, or by the record. The party cross-examining is not\nconcluded by such person's answer.\n