HARRISBURG (AP) – PA’s largest public pension system is dealing with a federal investigation, although officials with the Public School Employees’ Retirement System have yet to disclose the nature of the inquiry. State Treasurer Stacy Garrity, who is on the pension system’s board, told lawmakers that top retirement system officials have received federal subpoenas. The board late Tuesday night approved a resolution to hire a law firm to represent it “in matters relating to a federal investigation.” The disclosures come after the system said it is investigating a consultant’s incorrect calculation about the fund’s investment performance.