N.J. Stat. § 30:8-21
In all cases where any sheriff or undersheriff shall be by law authorized or required to confine or keep in jail any person arrested or in custody on any civil process, or in any civil suit or proceeding, by surrender in discharge of bail or in any other way, such sheriff or undersheriff shall deliver such person so arrested or in custody to the jail warden of such county, if there shall be one, within such jail, with a copy of the process, commitment or surrender by virtue of which such person was arrested or is in custody, and after such delivery such sheriff or undersheriff shall not be liable for any escape of such prisoner; but the board of chosen freeholders of such county, or their keeper or warden, if they shall have appointed one under the provisions of section 30:8-20 of this Title, shall, for any escape after such delivery, be liable in the same manner as the sheriff of the county would be if he had the custody, rule, keeping and charge of the county jail of such county and of the prisoners therein. Such sheriff or undersheriff may require such keeper or warden to give a receipt, upon the process or commitment by which such prisoner may be arrested or held, for the body of such prisoner.
N.J.S. § 30:8-21