A senior at Burlingame High School told police that he was playing a prank when he allegedly posted a threat online targeting a rally at his school, police said.
Authorities have not said what the 17-year-old boy wrote in the online post. But the post was alarming enough that the FBI and San Mateo Police Department teamed to arrest the boy at his school Monday morning.
The senior, who was not identified because he is a juvenile, was booked into Hillcrest Juvenile Hall on suspicion of making terrorist threats.
Someone outside California spotted the violent Internet scrawling that threatened a school rally and reported it to authorities, according to the San Mateo Police Department.
The FBI notified police in San Mateo, where the student lives, at 7 a.m. Monday.
Two hours later, FBI agents and cops went to the campus to interview the student. The boy admitted he posted the threat, but said it was only a prank, according to San Mateo police.
Authorities searched the boy’s home, but found no evidence of a weapon, police said.
Police say students were never in danger and classes were not affected.
In a statement, San Mateo police Chief Susan Manheimer said the threat posed “a significant potential danger to the school community,” and that such threats “will be met with zero tolerance.”
The threat comes just as a former San Mateo high school student stands trial for walking onto his campus wearing a vest packed with pipe bombs Aug. 24, 2009.
Alexander Youshock faces life in prison on charges that he attempted to carry out a deadly attack at Hillsdale High School. Youshock, who had flunked out of the high school in spring 2008, allegedly intended to exact revenge on at least three teachers. He set off two of the explosives, but no one was injured.
On Tuesday, the teacher who tackled then-17-year-old Youshock, potentially thwarting disaster, took the stand. He said Youshock appeared calm in the midst of chaos.
Bay City News contributed to this report.