A divided federal appellate court panel canceled plea deals for three defendants who are accused to plotting the 9/11 terrorist attacks that killed 2,976 in 2001.

A U.S. Court of Appeals for the District of Columbia Circuit panel upheld then-defense secretary Lloyd Austin’s withdrawal from terms with Khalid Sheikh Mohammed and two others charged in the 9/11 attacks.

The decision undoes an attempt to wrap up more than two decades of military prosecution beset by legal and logistical troubles.