N.J. Stat. § 40:37-18
Whenever by virtue of section 40:37-17 of this Title any park commission or other body has or shall have established any public park which is partly in another county, all ordinances, rules and regulations duly established by the park commission or body and applicable to the park shall be effective to the same extent in all portions of the park regardless of the county line. Every park police officer or other official empowered to make arrests in the county in which the park is controlled shall have the same powers of arrest in all parts of the park without regard to the county line. Proceedings against any person arrested therein shall be before a court of the county or municipality having local criminal jurisdiction, in which the offense was committed.
N.J.S. § 40:37-18