"We learned during the investigation that it may have been left there by a maintenance worker for one of the building tenants," Police Chief Glenn O'Reilly said.
As a precaution, police evacuated the Frank Burr Boulevard complex between Teaneck Road and Route 95 shortly after 7 p.m. Thursday, the chief said.
The Bergen County Bomb Squad responded and determined the item wasn't suspicious, he said.
Click here to follow Daily Voice Bergenfield and receive free news updates.