The threat "was found on a note in the hallway," Capt. Darren Sucorowski said. "The school resource officer and school administration decided to have the student's shelter in place and lock down the school."
Garfield police secured the school, with help from a Bergen County Regional SWAT Team, the county sheriff's office and GHS security.
Officers from Elmwood Park, Lodi, Passaic, Saddle Brook and the New Jersey State Police helped secure the outer perimeter and a search was conducted.
"Students were held in place until approximately 6:30 p.m., when it was determined that the threat was not credible," Sucorowski said.
Click here to follow Daily Voice Northern Highlands and receive free news updates.