N.J. Stat. § 34:13A-15
"Public fire department" means any department of a municipality, county, fire district, or the State or any agency thereof having employees engaged in firefighting provided that such firefighting employees are included in a negotiating unit exclusively comprised of firefighting employees.
"Public police department" means any police department or organization of a municipality, county or park, or the State, or any agency thereof having employees engaged in performing police services including but not necessarily limited to units composed of State troopers, police officers, detectives and investigators of counties, county parks and park commissions, grades of sheriff's officers and investigators; State motor vehicle officers, inspectors and investigators of the Alcoholic Beverage Commission, conservation police officers in the Division of Fish and Wildlife in the Department of Environmental Protection, State park police officers, marine patrolmen; correction officers, keepers, cottage officers, interstate escort officers, juvenile officers in the Department of Corrections and patrolmen of the Human Services and Corrections Departments; patrolmen of Capitol police and patrolmen of the Palisades Interstate Park Commission.
N.J.S. § 34:13A-15