N.J. Stat. Ann. § 2A:168-5

The Assignment Judge of the Superior Court in each county may appoint a chief probation officer, and, on application of the chief probation officer, such men and women probation officers as may be necessary. Before any order is made by such judge appointing any additional probation officers, a notice of the time and place, when and where such order shall be considered, shall be given to the board of chosen freeholders of the county and they shall be given an opportunity to be heard as to the necessity of such additional probation officers. All probation officers who are to receive salaries shall be appointed in accordance with the rules and regulations of the Civil Service Commission. Orders of appointment shall be in writing and be filed in the office of the county clerk.