N.J. Stat. § 40A:9-117a
The sheriff of each county may appoint a number of persons, not to exceed 15% of the total number of sheriff's officers employed by the sheriff and set forth in the sheriff's table of organization in the county budget, to the position of sheriff's investigator. All sheriff's investigators shall serve at the pleasure of the sheriff making their appointment and shall be included in the unclassified service of the civil service.
A sheriff's investigator appointed pursuant to this section shall have the same compensation, benefits, powers and police officer status as is granted to sheriff's officers. The duties of sheriff's investigators shall be law enforcement investigations and related duties. A person appointed to the position of sheriff's investigator shall, within 18 months of appointment, complete a police training course at an approved school and receive certification by the Police Training Commission as provided in P.L. 1961, c. 56 (C. 52:17B-66 et seq.). The implementation of this act shall not result in the layoff of permanent sheriff's officers.
N.J.S. § 40A:9-117a