The families of people killed in the September 11 attacks have been invited to military installations in four US states to watch pre-trial hearings at Guantanamo Bay for five men charged with planning or assisting the terrorist strike.
The hearings are closed to the public, but relatives who register in advance can watch on closed-circuit television at forts in New Jersey, Massachusetts, Maryland and New York City.
The suspects on trial before the US military commission on Cuban soil include Khalid Sheikh Mohammed, the self-professed mastermind of the September 11 attacks.
An earlier round of hearings in May was also transmitted to viewing locations for relatives of the victims, survivors of the attacks, and emergency personnel who responded to the disaster.
Those proceedings were an exercise in frustration for some viewers, as the suspects refused to co-operate with the court, or interrupted proceedings to kneel in prayer.
Jim Riches, whose firefighter son Jimmy died at the World Trade Centre, said he planned to view the hearing at Fort Hamilton in Brooklyn.
"It's difficult for the families. But it is 10 years later, and we have no justice," Mr Riches said. "I just wish it was being broadcast throughout the whole world so everyone could see it, and could see what these guys are like."
The nearly 3,000 people killed in the attacks have many relatives who could see the trial, but attendance at the first round of hearings last spring was light, with only a few dozen at each site.
Mr Riches said he did not expect a large crowd for today's session either, largely due to the pain of reliving the attacks.
"A lot of people are moving on with their lives. A lot of people are just trying to forget about it and move on. But you can't, really. They aren't going to walk back in through the door," he said, referring to the victims.