Principal Rodney Benedick called Erb after the message was discovered and the school was locked down while Pennsylvania State Police dispatched three troopers to the school, she said. Mercersburg Police Chief Larry Thomas also went to the school, she said.
"The principal had a pretty good idea who might have done it," Erb said. The student was questioned and confessed he had written part of the message, she said.
"At that point, we decided we had to evacuate the building," Erb said. The students were taken to the school stadium while staff and police broke up into teams and searched the building. E-mails had earlier been sent to teachers asking if anything suspicious was spotted, she said.
Once the search was completed, Erb said the students were brought back in, fed their lunches and school ended on schedule. The students were held outside for a couple of hours, she said.
A parent notification system eastablished after the incident last spring was used to call parents, she said. Parents had the option to come get their children and "a lot of kids were picked up and taken home," she said.
Some administrators and staff now also have radios, which helped keep the evacuation process orderly, Erb said.
"He was taken by state police for further questioning," Erb said of the student.
Students waiting in the stadium Friday were escorted back into the building if they needed to use a restroom, Erb said. When school resumes Monday, students could be facing "a more stringent policy on restroom usage," she said.
After the April 19 bomb threat, all but one set of restrooms remained open for a time. An aide was stationed outside and students had to sign in to use the bathrooms, which were then checked.