N.J. Stat. § 4:7-44
A person who shall violate any of the provisions of section 4:7-43 of this Title shall be liable to a penalty of fifty dollars ($50.00) for the first offense and one hundred dollars ($100.00) for the second and each subsequent offense, which penalty shall be sued for and recovered by and in the name of the department in the manner provided in article one of chapter twenty-three of this Title (s. 4:23-1 et seq.) and in such proceeding the defendant may be arrested upon the institution of the action.
If judgment is rendered for the plaintiff the court shall cause a defendant who shall fail to pay forthwith the amount of the judgment rendered against him, and all costs and charges incident thereto, to be committed to the county jail for a period of not less than five nor more than ninety days in the case of a first offense, and not less than ten nor more than two hundred days for a second and each subsequent offense.
N.J.S. § 4:7-44