A 15-year-old high school student has been arrested after confessing to San Diego cops that he was carrying an unloaded gun and planned to confront a bully with it. The Serra High School freshman was stopped by officers last week for skipping class but immediately told them about the .45-caliber semi-automatic handgun in his backpack. The gun was not loaded and the boy did not have any ammunition. The teen told officers that a fellow student had bullied him for weeks and then threatened his life. Police say the boy decided to steal the weapon that belonged to his late father and was kept in a lockbox.