New York Consolidated Laws, Criminal Procedure Law - CPL § 140.25 Arrest without a warrant;  by peace officer

(a) Any offense when he has reasonable cause to believe that such person has committed such offense in his presence;  and

(b) A crime when he has reasonable cause to believe that such person has committed such crime, whether in his presence or otherwise.

(a) An offense defined by a statute which such peace officer, by reason of the specialized nature of his particular employment or by express provision of law, is required or authorized to enforce;  or

(b) An offense committed or reasonably believed by him to have been committed in such manner or place as to render arrest of the offender by such peace officer under the particular circumstances an integral part of his specialized duties.

(a) He may arrest such person for any offense when such person has in fact committed such offense in his presence;  and

(b) He may arrest such person for a felony when he has reasonable cause to believe that such person has committed such felony, whether in his presence or otherwise.

(a) The “geographical area of employment” of any peace officer employed as such by any agency of the state consists of the entire state;

(b) The “geographical area of employment” of any peace officer employed as such by an agency of a county, city, town or village consists of (i) such county, city, town or village, as the case may be, and (ii) any other place where he is, at a particular time, acting in the course of his particular duties or employment;

(c) The “geographical area of employment” of any peace officer employed as such by any private organization consists of any place in the state where he is, at a particular time, acting in the course of his particular duties or employment.