New York Consolidated Laws, Election Law - ELN § 8-502. Challenges;  generally

Before his vote is cast at an election any person may be challenged as to his right to vote, or his right to vote by early mail, absentee, military, special federal or special presidential ballot.  Such challenge may be made by an inspector or clerk, by any duly appointed watcher, or by any registered voter properly in the polling place.  An inspector shall challenge every person offering to vote, whom he shall know or suspect is not entitled to vote in the district, and every person whose name appears on the list of persons to be challenged on election day which is furnished by the board of elections.