A South Carolina ninth-grader who shot the school resource officer with Socastee High School near Myrtle Beach on Tuesday began posting Twitter messages about his plan on Aug. 23, the first day of school.
The student posted Twitter updates up until Tuesday, and the principal told the Sun News private social media networks are difficult to police unless a direct threat or reference to the school occurs.
An unidentified male student opened fire on officer Erik Karney with a handgun and was taken into custody by the officer.
Police officers later found several unexplained devices at the school. A bomb squad was called in to dismantle the devices, Austin News reports.