New Milford Police have arrested a Schaghticoke Middle School student for the threat to the school that forced its evacuation on Tuesday.  The threat, written on a piece of paper discovered by a student, led to the arrest yesterday of a juvenile on a breach of peace charge.  The juvenile, whose name was not released due to his age, is a student at Schaghticoke and determined to be the only individual involved in the threat.  Police say no further arrests are expected.