The incident took place in Copiague on Monday, Oct. 24.
According to Suffolk County Police, a 13-year-old Copiague Middle School student posted in a social media group chat that if the school was in session on Oct/ 24, he would shoot teachers and students.
The post was shared by multiple students and a parent notified school officials who called the police, police said.
The teen was charged with making a threat of mass harm and will be arraigned in Suffolk County Family Court at a later date.
Click here to follow Daily Voice Brentwood and receive free news updates.