Only one member of the group, a 17-year-old boy, is from Lyndhurst, they said. The rest are from Passaic County.
They climbed in through an unsecured window of the old Lincoln School on Ridge Road at Gutheil Place around midnight Sunday, Detective Lt. Vincent Auteri said.
A passerby on Ridge Road heard the sound of breaking glass and called police, the lieutenant said.
The group ignored orders to come out, he said, so police established a perimeter with help from their colleagues from North Arlington and Rutherford.
They then threatened to send in a Bergen County Sheriff's K-9 unit, which also responded, Auteri said.
The group extensively damaged the building, which has been closed since the opening of the township middle school two years ago.
Charged with burglary and criminal mischief were two 18-year-olds -- Shaun Treloar of Hewitt and Joseph Wiebe of Clifton. Both were released on summonses to appear in court.
Police also signed delinquency complaints against the Lyndhurst teen, a 17-year-old Clifton resident and a 16-year-old Hewitt boy. Those complaints will be heard behind closed doors in the Family Part of Superior Court in Hackensack because of their ages.
Auteri thanked the other law enforcement agencies, as well as the good Samaritan who called police.
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