N.J. Stat. § 30:8-24.2
In any county of the second class where the sheriff of the county has heretofore prior to December 1, 1956, by written notice, directed the board of chosen freeholders of such county to take and have the custody, rule, keeping and charge of the jail or jails in such county, the board of chosen freeholders of such county, by resolution, shall direct the sheriff of the county to take and have the custody, rule, keeping and charge of the jail or jails in such county and, thereupon, the said sheriff shall have the same powers and duties in respect to such custody, rule, keeping and charge of the jail or jails in such county in the same manner and to the same effect as the sheriff of said county had prior to the giving of the aforesaid written notice of direction to the board of chosen freeholders of the county.
N.J.S. § 30:8-24.2