NEW : Sulaiman Abu Ghaith gave investigators a 22-page statement , prosecutors say . No trial date has yet been set . NEW : The FBI has been investigating the case for months and is expected to file charges against him in the coming days. Abu Ghaith is accused of conspiracy to kill U.S. nationals . After 9/11 attacks , he warned that `` the storms shall not stop , especially , the airplane storms ''
NEW : Sulaiman Abu Ghaith gave investigators a 22-page statement , prosecutors say . NEW : The FBI has been investigating the case for months and is expected to file charges against him in the coming days. Abu Ghaith is accused of conspiracy to kill U.S. nationals . After 9/11 attacks , he warned that `` the storms shall not stop , especially , the airplane storms ''