Since Friday, three threats have been written on school walls in the Putnam County School District.
The first message was discovered on Friday at Palatka High School, the second turned up Monday at Interlachen High School, and the third appeared on Tuesday at C.H. Price Middle School.
One person has been arrested: a 12-year-old believed to be responsible for the threat at C.H. Price Middle School.
"It's disturbing, and it's upsetting a lot of the schools and the flow of instruction in the schools," said Bruce Bolden, a concerned grandparent. "You got kids that aren't comin' to school 'cause they're scared."
Hundreds of students in the district stayed home from school on Monday.
The Putnam County Sheriff's Office has provided security protocols to the schools and plans to continue to secure the two high schools while the investigation is ongoing. But the office isn't releasing the exact content of the threats to avoid encouraging imitators.
"At this point in time, the investigation is continuing into the messages at the other two schools," said Hancel Woods, of the Putnam County Sheriff's Office.