N.J. Stat. § 43:16A-48.8
Notwithstanding any other provision of law regarding the Police and Firemen's Retirement System or the Public Employees' Retirement System, when any police officer member of the Police and Firemen's Retirement System transfers his employment to a municipality which has within 1 year of the transfer first established a police department and has not at the time of the transfer adopted the Police and Firemen's Retirement System, so that the police officer is thereby required to transfer to membership in the Public Employees' Retirement System, and the municipality thereafter adopts the Police and Firemen's Retirement System and the police officer elects to transfer back to membership in that system, the full amount of the police officer's contributions and the full amount of the contributions made by the police officer's former employers shall be transferred by the Public Employees' Retirement System to the Police and Firemen's Retirement System.
N.J.S. § 43:16A-48.8