N.J. Stat. § 19:15-18
The members of the district boards and any duly authorized challenger, respectively, shall at any election challenge every person who shall claim to have a right to vote therein whom they or he shall know, suspect or believe not to be qualified or entitled to so vote, and said members of the district board or challenger shall have the power and right to ask all questions which are suitable and necessary to determine such person's right.
No member of the district board and no duly authorized challenger shall, however, challenge, delay or prevent the right to vote of any person because of that person's race, color, national origin, expected manner of casting a vote or residence in a particular ward, housing complex or section of a municipality or county, provided that nothing herein shall be construed to prohibit a challenge based upon the failure of the challenged voter to meet the applicable statutory residency qualification for voting in the particular election district. Any member of the district board or duly authorized challenger who violates this section is guilty of a disorderly persons offense.
N.J.S. § 19:15-18