Galloway Police Chief Pat Moran said there was no proof the 16-year-old was planning to make an explosive device, The Press of Atlantic City reported. But he said the search by local police and the Atlantic County Prosecutor's Office turned up chemicals that, when mixed, could have been used in a bomb as well as electronics equipment.
The search was carried out after officials at Cedar Creek High School notified authorities a student "demonstrated behavior that caused them to be concerned."
The boy was being held in a juvenile detention center. Moran said he and his family had cooperated with investigators.
The school was swept by bomb-sniffing dogs, but no trace of explosives was detected.