The jury in the trial of convicted 9/11 plotter Zacarias Moussaoui has reached a decision on whether or not he should be sentenced to death.
The verdict will be announced at a US court in Virginia at 1630EDT (2030GMT).
Moussaoui has admitted involvement in the attacks and faces life in a US prison or execution.
Moussaoui, a Moroccan-born Frenchman, is the only person to have been convicted in connection with the 9/11 attacks on New York and Washington.
During the six-week sentencing trial, the jury of nine men and three women sat through harrowing evidence gathered from the bloodiest terror attacks in US history.
Testimony was heard from witnesses who survived the attacks on New York and Washington and pictures were shown of the carnage caused when the hijacked aircraft crashed into their targets.
The jury also heard a voice recording from the cockpit of the hijacked United Airlines flight that crashed into a field in Pennsylvania.