N.J. Stat. § 40A:14-106
The governing body of any county, adopting rules for the regulation of traffic upon the county highways and roads and for the enforcement of laws pertaining thereto, by ordinance or resolution, as appropriate, may create and establish a county police department and force and provide for its maintenance, regulation and control. Except as otherwise provided by law, the governing body may appoint a chief of the department and such other members, officers and personnel as shall be deemed necessary, determine their terms of office, fix their compensation and prescribe their powers, functions and duties. The governing body shall adopt and promulgate rules and regulations for the government of the department and force and for the discipline of its members.
N.J.S. § 40A:14-106