New York Consolidated Laws, Criminal Procedure Law - CPL § 140.30 Arrest without a warrant;  by any person;  when and where authorized

1. Subject to the provisions of subdivision two, any person may arrest another person (a) for a felony when the latter has in fact committed such felony, and (b) for any offense when the latter has in fact committed such offense in his presence.

2. Such an arrest, if for a felony, may be made anywhere in the state.  If the arrest is for an offense other than a felony, it may be made only in the county in which such offense was committed.