The Essex County prosecutor announced Monday the arrest of a 15-year-old student in connection with several threats that prompted a school lockdown two weeks ago.

On March 11, West Essex Regional High School in North Caldwell was locked down for approximately three hours after authorities say several threats were made. Police say the 15-year-old made the threats with graffiti messages throughout the building.

According to Essex County Prosecutor Paula Dow, the lockdown cost law enforcement officials approximately $60,000 and disrupted the community.

Investigators say they found guns and ammunition during a search of the teen?s home. It is unclear who the guns belong to.

The teen?s name has not been released because he is a minor. It is unclear if he will return to school.

Schoollock downs in North Caldwell a 'precaution'