A juvenile is facing charges that he made a bomb threat that resulted in the evacuation of Swampscott High School Thursday, police said. The juvenile was arrested at 5:20 p.m. Thursday at the town’s public library, said Lieutenant Tom Stephens of the Swampscott police. The juvenile appeared in Lynn Juvenile Court Friday on charges including disturbing the peace and making a false bomb threat. The threat to Swampscott High was called into 911 Thursday morning, prompting officials to evacuate the school. A search of the building found “no credible threat,” Officer Rich Cassidy said Thursday. School resumed Friday.