74 Pa. Stat. § 102
As of the date of the grant and conveyance aforesaid, the exclusive jurisdiction over the lands so granted and conveyed is hereby ceded to the United States of America by the Commonwealth of Pennsylvania; and said lands shall be exempt from the payment of all taxes, State and local: Provided, That the Commonwealth of Pennsylvania shall retain a concurrent jurisdiction with the United States over the land so granted and conveyed for the purpose of serving all civic processes: And provided further, That such criminal processes as may issue under the authority of the Commonwealth against any person or persons charged with crimes or misdemeanors committed without the area so granted and conveyed may be executed therein in the same manner as though this cession had not been made.
74 P.S. § 102