Why am I being notified by a Constable about an outstanding Arrest Warrant?

Summary Warrants are issued to certified Pennsylvania State Constables for service. Constables can execute Warrants issued on Citations for Traffic (including Parking) violations, Non-Traffic (Summary State Code and local Ordinance) violations, as well as Court subpoenas and Civil processes. Constables may execute Warrants in any part of Pennsylvania, and they have arrest powers on their Warrants and on other crimes committed in their view.