WASECA Minn. – A 17-year-old boy in Waseca has pled not guilty to charges that he plotted to kill his family and then stage an attack on his school. John David LaDue wore arm and leg shackles and an orange jumpsuit as deputies escorted him into the courthouse for his appearance Monday in Waseca County. He answered Judge Gerald Wolf’s questions in a calm, clear voice. Wolf ordered a study to determine whether the boy should be charged as an adult. The study will include psychological exams and is expected to take several weeks. Prosecutors say the teenager outlined his plan for a school attack in a 180-page journal. He was arrested at a storage locker that authorities say contained bomb-making materials and had numerous guns in his room.