NEW: The alleged mastermind of the Sept. 11 terror attacks and two other terrorists being held on Guantánamo Bay will plead guil

NEW: The alleged mastermind of the Sept. 11 terror attacks and two other terrorists being held on Guantánamo Bay will plead guilty as part of a deal that’ll allow them to skirt the death penalty, prosecutors said Wednesday. “The Convening Authority for Military Commissions has entered into pretrial agreements with Khalid Shaikh Mohammad, Walid Muhammad Salih Mubarak Bin ‘Attash, and Mustafa Ahmed Adam al Hawsawi, three of the co-accused in the 9/11 case,” an Office of Military Commissions spokesperson confirmed. More: Source: Police frequency