VOICE-OVER:(NOTES: AP Graphic / 9/11 FILE / COURT DOCUMENTS)Already described as the 'trial of the century,' the long-stalled prosecution of five Guantanamo prisoners accused of planning and aiding the September 11, 2001 attacks heads to an arraignment hearing Saturday.After years of political and legal battles, Khalid Sheikh Mohammed and his co-conspirators face counts of terrorism and 2,976 charges of murder _ one for each victim when four hijacked commercial airliners slammed into New York's World Trade Center, the Pentagon and a field in Pennsylvania.(SOT: Retired Colonel Morris Davis, former chief military prosecutor)(Col. Morris Davis, former chief military prosecutor)"Khalid Sheikh Mohammed, regardless of the forum, he's proud of what he did. He's going to try to make a spectacle out of it, use it for his last hurrah to claim credit for what he did." (NOTES: AP Graphic / COURT SKETCH)VOICE-OVER:Along with Mohammed, Yemeni Ramzi Binalshibh, Pakistan's Ali Abd al Aziz Ali and Saudis Walid bin Attash and Mustafa Ahmed al Hawsawi face possible death sentences.The path to a legal hearing for Mohammed has been anything but smooth _ retired Colonel Morris Davis was chief prosecutor at Guantanamo Bay from 2005 to 2007.(SOT: Retired Colonel Morris Davis, former chief military prosecutor)"In September 2006 a plane landed 14 individuals got off the plane, one was Khalid Sheik Mohammed // Of the 14 guys that got off the plane that day in Guantanamo, one has been tried and 13 are still biding their time in limbo at Guantanamo."(NOTES: PRESIDENTIAL SEAL / PRESIDENT OBAMA SPEAKING)VOICE-OVER:First arraigned in 2008, the case against Mohammed was put on hold after President Barack Obama's election when the president wanted the case transferred to civilian court _ but Congress blocked the move. (NOTES: FILE MILITARY TRIBUNAL HEARING ROOM)Changes have been made to military commissions since 2001, but defense lawyers and human rights groups still say the system favors the prosecution.The military commissions will also prevent a public airing of the harsh treatment endured by Mohammed, who was subjected to water-boarding and forms of interrogation while held by the CIA.Pretrial motions and hearings are likely to take at least a year.(SOT: CHARLES STIMSON, MILITARY LEGAL EXPERT)"There is going to be this start, stop, start, stop, start, stop because of the volume of evidence and the complex nature of this worldwide conspiracy // a conspiracy of a worldwide nature involving dozens of countries, involving hundreds of people. //You can't even compare the scale of this except to say something like the Nuremburg trials. It is that vast and that complex. "(NOTES: VARIOUS / GUANTANAMO BAY NAVAL)VOICE-OVER:Highlighting intense interest, Pentagon officials expect hundreds of journalists to travel to Cuba to witness the tribunal hearings.Tracy Brown,Associated Press[SIGOUT/REPORTER, LOCATION, ASSOCIATED PRESS](****END****) ANCHOR VOICE: TRACY BROWN-------------------------VIDEO PRODUCER: TRACY BROWN---------------------------VIDEO SOURCE: AP, POOL, FILE-----------------------VIDEO APPROVAL: BOB MCCALL----------------------------VIDEO RESTRICTIONS: NONE ----------------------------------MARKET EMBARGO (S): NONE--------------------------------SCRIPT/WIRE SOURCE: