N.Y. Mental Hyg. Law § 33.15

§ 33.15 Habeas corpus.\n (a) A person retained by a facility or the department or a relative or\nfriend on his behalf is entitled to a writ of habeas corpus to question\nthe cause and legality of detention upon proper application.\n (b) Upon the return of such a writ of habeas corpus, the court shall\nexamine the facts concerning the person's alleged mental disability and\ndetention. The evidence shall include the clinical record of the patient\nand medical or other testimony as required by the court. The court may\nreview the admission and retention of the person pursuant to the\nprovisions of this chapter. The court shall discharge the person so\nretained if it finds that he is not mentally disabled or that he is not\nin need of further retention for in-patient care and treatment.\n (c) In a subsequent application for a writ, any party to the\nproceeding may introduce evidence or records from a prior hearing or\ntrial and such records shall have the same force and effect as\ntestimonial evidence.\n (d) The application for a writ of habeas corpus and the proceedings\nupon it shall follow the procedure set forth in article seventy of the\ncivil practice law and rules.\n (e) The director of the facility where the person is detained shall\nforthwith notify the mental hygiene legal service of any such\napplication for a writ and provide it with information as to the case.\n