A newly unsealed court filing has revealed previously unknown details about the Trump administration’s operation to remove Venezuelan nationals under the Alien Enemies Act and threatens to undermine key elements of its legal defense.

Many of the Venezuelan immigrants who have been removed under the Alien Enemies Act have been sent to a prison in El Salvador known as the Centro de Confinamiento del Terrorismo, or CECOT. Grove said it is unclear whether that was the plan for the folks represented in this case, too.