Jacob M. Rollins-Young, 17, a student at Ithaca High School, was arrested and charged with a felony Tuesday after threatening a mass shooting at his school via Facebook, according to a press release from the Ithaca Police Department. Police charged Rollins-Young with originating a terroristic threat — a Class D felony — Saturday night, and he was arrested Monday night, according to The Ithaca Journal. The police responded to an alert at approximately 3:28 p.m. Saturday, after concerned students who had seen Rollins-Young’s Facebook comments notified Ithaca High School principal Jason Trumble, according to the release. The Facebook posts included the narrative of an imagined shooting — “Local Teen Opens Fire at Ithaca High” — in which Rollins-Young describes a “Caucasian male” opening fire with an assault rifle “in a cafeteria nearby.” He also repeatedly suggested that he was not joking, according to the felony complaint. In a Facebook conversation between several IHS students, “one student became upset and made a direct threat to another student followed by a threat of violence to the entire IHS community,” according to an email sent by school administrators to students’ parents.