53 Pa. Stat. § 23539
If, for reasons of economy or lack of funds, it becomes necessary for any city of the second class to reduce any employes of its bureau of police, then the city shall follow the following procedure:
First. If there are any employes in its bureau of police eligible for retirement under the terms of any police pension fund, then such reduction shall be made by retirement on pension of the oldest in age and service.
Second. If the number of employes in its bureau of police eligible for retirement under the pension fund of said city is insufficient to affect the reduction in number desired by the city, or if there is no eligible person for retirement, or if no retirement fund exists in said city, then the reduction shall be effected by suspending the last man or men, starting with probationers, that have been appointed. Such removal shall be accomplished by suspending in numerical order, commencing with the last man appointed, all recent appointees, until such reduction shall have been accomplished. Whenever the number of employes in the bureau of police shall be again increased in number, or if any vacancies occur, the employes suspended under the terms of this act shall be reinstated to their former class before any new appointees are appointed, in the inverse order in which they were suspended.
53 P.S. § 23539