NEW : ` ` Mr. Chae '' was convicted of torching a Korean palace in 2006 . NEW : ` He is currently serving his sentence at the prison camp for political prisoners ', which has been closed down since he escaped from there last year. NEW : Easy access , lightly populated area dictated Namdaemun choice , police say . The more-than-600-year-old Namdaemun was country 's oldest wooden structure .
NEW : `` Mr. Chae '' was convicted of torching a Korean palace in 2006 . NEW : Chae has confessed to starting the Namdaemun fire , police chief says . NEW : Easy access , lightly populated area dictated Namdaemun choice , police say . The more-than-600-year-old Namdaemun was country 's oldest wooden structure .