N.J. Stat. Ann. § 40A:14-172

Section 40:174-148 of the Revised Statutes is saved from repeal. [The compiled act (P.L.1920, c. 163) saved from repeal by this section provides that in cities of the first class, a member of the police department or force holding the position of detective for a period of at least 5 years, shall not be reduced to a lower position except upon charges and after hearing.]