New Jersey Statutes Title 40A. Municipalities and Counties 40A § 9-3

The board of chosen freeholders of any county, or the governing body of any municipality shall not make any rules or regulations designed to bar any person from holding a county or municipal position or employment or applying therefor, who is 40 years of age or more. This section shall be inapplicable to policemen or firemen or guards employed in the service of any county or municipal penal institution or to court attendants in first and second class counties whose duties require the custody and handling of prisoners.