A Cranford High School student who caused widespread panic by falsely reporting a threat at the high school has pled guilty to a third degree charge of creating a false public alarm.

The 15-year-old Cranford teenager admitted to using the social media app, Yik Yak, to post a message alluding to a threat against Cranford High School students last October, acting Union County Prosecutor Grace H. Park announced Wednesday. The message, which was posted on Oct. 30, alluded to a "big surprise" at Cranford High School the next day. The social media post advised students to "watch your backs" shortly before 11:30 a.m., Union County Prosecutor's Office Juvenile Unit Supervisor Susan Gleason.

Yik Yak allows subscribers to anonymously post messages that are accessible only by other Internet or mobile phone users within a small geographic radius of where the messages were originally sent, the Prosecutor's Office reported. The Cranford Police Department was notified of the suspicious message shortly after it was posted on Yik Yak, Gleason stated. The Union County Sheriff's Office K-9 Units were dispatched and a complete sweep of high school was conducted, but no explosives, firearms, or otherwise dangerous substances or objects were located.

A subsequent joint investigation by the Prosecutor's Office Juvenile Unit and the Cranford Police Department identified the juvenile defendant as a suspect, and he was located at his home. Under the terms of a plea agreement, the defendant, who was 14 at the time of the incident, was placed on probation for 12 months and now must complete 40 hours of community service with the Elizabeth Police Department, the Prosecutor's Office stated.

The student also must pay restitution in the amount of $2,000 and attend school with no unexcused absences, tardiness, or suspensions for the duration of the current school year.