N.J. Stat. § 40:37-163
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 received permanent disability from injury or sickness incurred while in actual service, so as to incapacitate him from duty, shall upon the certificate of the police surgeon or other physician, or of a board of physicians designated by a board consisting of two members of the commission, two members of the police force and a fifth member to be chosen by the four other members, be so pensioned and retired if said injury was incurred in the performance of duty, and shall be paid an annual pension equal to 2/3 of his average annual salary for the last 3 years of his employment, but if said injury shall have been incurred while in service but not in the performance of duty and said member has served for 25 years or more in the police force or department, he shall be paid an annual pension equal to 1/2 of his average annual salary for the last 3 years of his employment.
N.J.S. § 40:37-163