The man accused of being the main plotter in al-Qaida’s Sept. 11, 2001, attacks has agreed to plead guilty, the Defense Department said Wednesday. Khalid Sheikh Mohammed and two accomplices in the attack are expected to enter the pleas at the military commission at Guantanamo Bay, Cuba, as soon as next week. Terry Strada, the head of one group of families of the nearly 3,000 direct victims of the 9/11 attacks, invoked the dozens of relatives who have died while awaiting justice for the killings when she heard news of the plea agreement. In response to the plea deal, Terry Strada said "I'm extremely disappointed that they chose today of all days, that we're also here in our courtroom, you know, trying to hold the kingdom accountable, and they pull this stunt on us." The U.S. agreement with the men to enter into a plea agreement comes more than 16 years after their prosecution began for al-Qaida’s attack, and more than 20 years after militants flew commandeered commercial airliners into buildings, killing nearly 3,000 people.