WASHINGTONVILLE - "Wat would u do if someone shot up the school tomorrow?""I need a gun."Police said Washingtonville High School senior Brendan Vaughan posted those messages to the social media site Snapchat, leading to Vaughan’s arrest on three charges, including a felony count of making a terroristic threat. The charges and the details of the investigation that led to the charges are spelled out in a criminal complaint filed in Washingtonville Village Court.