Bomb threats on consecutive days disrupted classes at Cobleskill-Richmondville High School and led to the arrest of a student there last week.
State Police from Cobleskill charged the 16-year-old boy with falsely reporting an incident, a Class D felony, on Friday.
Students discovered and reported the first threat on the stall in a boys' bathroom on Wednesday.
School officials called in State Police, and while troopers were at the school Thursday, a student discovered a second threat in a boys' bathroom.
"The proximity couldn't have been better," C-R Superintendent Carl Mummenthey said of the second message being found while troopers were at the school.
The threats were only one or two words, Mr. Mummenthey said.
"Both referenced a bomb, but there was no reference to date, time, place or intention," he added. "They were very non-specific."
Following safety policy, school officials had to take the threats seriously. The school was under "shelter-in-place" status both days, which is a low-level precaution.
Shelter in place meant students couldn't move from classroom to classroom but teaching could continue.
"We could keep things going, but it was disruptive," Mr. Mummenthey said.
The fact that the charge is a Class D felony indicates that authorities don't take threats lightly, he said.
"I hope this sends a message," Mr. Mummenthey said. "This is serious, and we're going to hold people accountable."
Reviewing the incident at Monday night's school board meeting, board member Susan Strasser urged parents and grandparents to talk to youngsters.
"This is not funny, and it costs taxpayers money," she said. "And felonies don't drop off your record."
The student, whose name was not released by State Police or C-R, is to be in Richmondville Town Court today, Wednesday.