North Korea sentenced 21-year old American student Otto Warmbier to 15 years of hard labor after finding him guilty of crimes against the state. Warmbier was arrested for trying to steal a propaganda sign from a hotel while visiting North Korea in January 2016.North Korea throws US student in jail for 15 years | He jusAmerican Student Sentenced to 15 Years in North Korean Jail. He may have been forced to make a formal apology.t stole a poster from a hotel.