* Defendants charged with plotting Sept. 11 attacks
* Defense lawyers want to know who's listening in
* Attorney-client talk is supposed to be private
By Jane Sutton
GUANTANAMO BAY U.S. NAVAL BASE, Cuba, Feb 12 (Reuters) - U .S. intelligence agents receive a raw feed of everything picked up by the microphones in the Guantanamo courtroom where five prisoners face capital charges of plotting the Sept. 11 attacks, a court technician testified on Tuesday.
But courtroom technology director, Maurice Elkins, said he did not know whether those agents had the technology necessary to isolate individual voices and background conversations, whether they had the ability to record what they heard, or even who they are.
The issue of who might be listening in has dominated this week's pretrial hearings for the alleged mastermind of the hijacked plane plot, Khalid Sheikh Mohammed, and four other captives accused of aiding and training the hijackers.
Defense lawyers contend that their confidential conversations with clients, and among themselves, are being monitored and possibly recorded at the Guantanamo Bay U.S. Naval Base in Cuba. Defendants have a legal right to consult their lawyers in private, and lawyers have an ethical duty to ensure the conversations are confidential.
Defense lawyers said they only learned that intelligence agents were monitoring the courtroom proceedings on Jan. 28, when someone outside the courtroom cut the public audio feed under the mistaken belief that a secret had been disclosed.
Technicians have since dismantled the "kill switch" that let them cut the feed, and altered the microphones at the lawyers' tables to prevent live microphones at nearby tables from picking up whispered conversations.
Instead of pushing a button to mute the microphones, lawyers must now push a button to activate them.
The court got a detailed explanation on Tuesday as to how the recording system and the microphones work, complete with detailed audio-flow schematics whose necessity the judge questioned.
"The issue before me is not all this wire diagram stuff. The issue before me is the ability of third parties to overhear conversations," said the judge, Army Colonel James Pohl.
Elkins, the technology director, testified that he did not recall whether he had told defense attorneys prior to their clients' May 2012 arraignment that anyone other than the stenographers and interpreters were listening from outside the courtroom.
VOICE-FILTERING SYSTEM IN USE
Stenographers received an unfiltered feed that picks up everything audible to the microphones, he said.
"Would it be similar to sitting in a restaurant and just hearing conversations all around you that you couldn't make out?" asked prosecutor Clay Trivett.
"That's a good analogy," Elkins replied.
He said the stenographers used a filtering system that allowed them to isolate and record individual voices. He did not know, however, if the intelligence agents had the commercial software and technology necessary to pick out or record background conversations.
No one has identified which intelligence agencies are listening to the Guantanamo courtroom, where the defendants previously held by the CIA are to be tried.
The outside monitors are identified only as "O.C.A.", an abbreviation for Original Classification Authority, meaning the agency or official who first declared information pertaining to the case as Top Secret.
Elkins said he did not know whether he had ever trained or had contact with any of them. "I wouldn't know O.C.A. if I walked next to O.C.A. on the street or played basketball in the gym with O.C.A.," he said.
The defendants in the case could face the death penalty if convicted in the Guantanamo war crimes tribunal on charges that include terrorism, conspiring with al Qaeda, and hijacking and murdering 2,976 people. This week's hearing was supposed to address whether the charges were properly filed, but have been sidetracked by the eavesdropping issue. (Editing by David Adams and Philip Barbara)