N.Y. Mental Hyg. Law § 29.19
A person who has been committed or admitted to a department facility or a hospital licensed or operated by the office of mental health and who has been reported as escaped therefrom or from lawful custody, or who resists or evades lawful custody; and any patient for whom the director of a hospital operated by the office of mental health, or the director's designee, has terminated a conditional release and ordered such patient to return to such facility; and any patient for whom a director of an assisted outpatient treatment program, as defined in subdivision (a) of section 9.60 of this chapter, or the director's designee, or anyone designated pursuant to section 9.37 of this chapter, has directed the removal to a hospital pursuant to subdivision (n) of section 9.60 of this chapter, may be apprehended, restrained, transported to, and returned to such school or hospital by any peace officer, acting pursuant to his special duties, or any police officer who is a member of an authorized police department or force or of a sheriff's department, and it shall be the duty of any such officer to assist any representative of a department or licensed facility, or an assisted outpatient treatment program, to take into custody any such person or patient upon the request of such representative, director or designee.
N.Y. Mental Hyg. Law § 29.19