N.J. Stat. Ann. § 2A:158-1.1

Any person appointed to the office of county prosecutor shall devote his entire time to the duties of his office and shall not engage in the practice of law or other gainful employment, except those appointed to that office in counties of the third class having a population between 65,000 and 85,000. No exception to the requirement that a prosecutor serve on a full-time basis shall be permitted on or after April 14, 1986.