N.Y. Veh. & Traf. Law § 204

§ 204. Subpoenaing hearing referees. No officer or employee of the\ndepartment of motor vehicles who has conducted a hearing concerning an\nowner or operator of a motor vehicle or motorcycle shall be required to\nappear in any court as a witness in a civil action in which such owner\nor operator is a party except pursuant to a subpoena signed by a judge\nof a court of record, or a judge of the court in which the action is\npending, issued upon an application to such judge after, at least, one\nday's notice to the commissioner or a deputy commissioner of motor\nvehicles.\n