The self-proclaimed 'mastermind' behind the Sept. 11 attacks was arraigned today and is set to face trial.Khalid Sheikh Mohammed and four co-defendants faced a judge at Guantanamo Bay today for allegedly planning and executing the Sept. 11 terrorist attacks. Relatives of some of the victims watched the court proceedings through closed-circuit TV at military bases, including Fort Hamilton in Brooklyn.The five defendants have been charged with terrorism, hijacking and 2,976 counts of murder, one charge for each victim of the Sept. 11 attacks. If found guilty, they could all face the death penalty.Families of victims say they're hopeful that the judicial process will bring Mohammed and the four other men to justice.