N.J. Stat. Ann. § 40:37-164

Every member of the county park police force or department having paid into the fund the full amount of the annual assessments or contributions required of him and who shall have attained the age of 60 years and have served in all for a period of 20 years in the police force or department, such service not being required to be continuous, may, by the vote of the commission, be so pensioned and retired, and shall, upon reaching the age of 60 years, and having served for any period of 20 years, on application be so pensioned and retired.