New York Consolidated Laws, Election Law - ELN § 5-220. Registration;  challenge after registered

1. Any person may challenge the registration of a voter by executing and delivering to the board of elections or a board taking registrations, his affidavit that he had reason to believe that such voter's registration should be cancelled.  Such affidavit shall contain the affiant's full name, residence, and business address, the name of his employer, the registration serial number of the person challenged and a recital of the reasons and the facts supporting affiant's belief that the person challenged lacks the qualifications for voting prescribed in this chapter and specified in such affidavit.  The affidavit shall state if the reasons for challenge are based upon the affiant's personal knowledge, or upon information received from another person.  If the affiant's belief is based upon information furnished by another, the affidavit shall recite the name of the person furnishing the information and the basis for his information.  After the affiant has signed such affidavit a member of such board shall read to him and request him to sign the following oath, which shall be subscribed by such affiant:  “I do solemnly swear (or affirm) that the foregoing statement made by me on (insert day, month and year) is a truthful disclosure of the reasons for my belief that the registered voter therein named is not qualified to continue to be registered in the election district in which he is now registered.”  If the affiant shall take and sign such oath, the members of the board shall sign their names as witnesses below the affiant's subscription to such oath.  Each such affidavit shall be directed toward the challenge of only one registrant.  The board shall give full assistance to any person desiring to execute such an affidavit.  The board of elections shall furnish the necessary forms.  Upon receipt of such affidavit the board of elections forthwith shall conduct an investigation of the voter's qualifications to remain registered in the same manner as provided for applications for personal registration by mail.  Any person whose registration is so challenged shall be notified thereof by the board of elections by registered or certified mail within five days after the affidavit is received by it.

2. If the board of elections cannot complete its investigation, or cannot make a determination before the next election at which the registrant could vote, it shall place his name on a challenge list as a person to be challenged when voting.