An Austrian court has found a 14-year-old boy guilty of planning to blow up Vienna’s main railway station after being radicalized by Islamic extremists. The court in St. Pölten, west of Vienna, also found the defendant, who was not identified, guilty Tuesday of planning to join extremist fighters in the Middle East, a punishable offense in Austria. The youth was sentenced to two years in juvenile detention, with 14 months of the term suspended. Since he has spent seven months in custody, he is expected to be behind bars for only three more. The police say they found plans for such an attack on the youth’s computer, and his defense lawyer, Rudolf Mayer, said he had acknowledged his guilt.