PORT JERVIS – A series of frightening incidents, involving rifle cartridges found at Port Jervis High School, a social media posting threatening violence at the school, and an alarming note discovered in a classroom, has police beefing up patrols at the school and the district working to reassure students and parents.Port Jervis High School Principal Andrew Marotta sent a letter to the school community in which he said the "No 1 priority" is keeping students safe.