N.Y. Crim. Proc. Law § 660.20

§ 660.20 Examination of witnesses conditionally; grounds for order.\n An order directing examination of a witness conditionally must be\nbased upon the ground that there is reasonable cause to believe that\nsuch witness:\n 1. Possesses information material to the criminal action or\nproceeding in issue; and\n 2. Will not be amenable or responsive to legal process or available\nas a witness at a time when his testimony will be sought, either because\nhe is:\n (a) About to leave the state and not return for a substantial period\nof time; or\n (b) Physically ill or incapacited.\n