September 10, 2009 1:31 PM

Agent: Moussaoui Confession Delay Hurt

(CBS/AP)  The confession given by al Qaeda terrorist Zacarias Moussaoui last year could have helped track down several Sept. 11, 2001, hijackers if investigators had heard it when he was arrested in the month before the attacks, a former FBI agent testified Thursday.

In particular, Moussaoui's admission that he received more than $14,000 in wire transfers from a man using the name Ahad Sabet could have allowed the FBI to backtrack through Western Union, cell phone, calling-card and motor vehicle records, as well as leases, to identify at least five of the 19 hijackers, former agent Aaron Zebley said at Moussaoui's death penalty trial.

Rulings by U.S. District Judge Leonie Brinkema prevent Zebley from offering explicit speculation about what the FBI could have accomplished had it known this information when Moussaoui was arrested in August 2001. But the clear implication is that Moussaoui's refusal to give a timely confession thwarted some of the FBI's best opportunities to prevent or at least minimize the Sept. 11 attacks.

As it was, certain details came out when Moussaoui pleaded guilty in federal court in April.

Moussaoui is the only person in this country charged in the attacks that killed nearly 3,000 people when al Qaeda flew hijacked planes into the World Trade Center, the Pentagon and a Pennsylvania field.

He pleaded guilty in April to conspiring with al Qaeda to hijack aircraft and commit other crimes, but he denies a specific role in 9/11. The sentencing trial now under way will determine whether he is executed or imprisoned for life, the jury's only choices.

When Moussaoui pleaded guilty, he confessed his al Qaeda membership and divulged numerous details of his terrorist plans, including his flight training, his receipt of al Qaeda money from an individual in Germany, and al Qaeda's general plans to hijack aircraft and crash them into prominent U.S. targets.

Zebley testified that the details of Moussaoui's confession, had they been known before 9/11, could have provided multiple leads for the FBI, including tracking al Qaeda's money trail and assigning more agents to the case.

On Wednesday, a former top security official at the Federal Aviation Administration testified that numerous security measures could have been implemented to protect against hijackings had officials known of Moussaoui's terrorist plans.

Robert Cammaroto said the FAA could have redeployed federal air marshals, tightened security checkpoints and directed flight crews to resist hijackers if they had known that al Qaeda terrorists were training pilots to take over planes and fly them into buildings.

Earlier in the trial, the FBI agent who arrested Moussaoui said he spent four weeks warning his bosses about the radical Islamic student pilot. Harry Samit said bureaucratic resistance to his efforts to subject Moussaoui to a thorough investigation blocked "a serious opportunity to stop the 9/11 attacks."

Moussaoui was arrested Aug. 16, 2001, on immigration violations after he aroused suspicion at a Minnesota flight school. He lied to agents and insisted his flight training was for personal enjoyment.

To obtain the death penalty, prosecutors must prove that Moussaoui's actions caused the death of at least one person on 9/11. They argue that he could have prevented or at least minimized the attacks if he had confessed and alerted federal agents to the imminent threat posed by al Qaeda.

The defense argues that nothing Moussaoui said after his arrest would have made any difference to the FBI because its bureaucratic intransigence rendered it incapable of reacting swiftly to Moussaoui's arrest under any circumstances.

Prosecutors argue that Moussaoui was obliged to tell the truth once he decided to talk to federal agents, and that the jury can consider what might have happened if Moussaoui had confessed.

Meanwhile, the 4th U.S. Circuit Court of Appeals ordered Brinkema to make public copies of certain documents, videos and photographs the day after they are introduced as evidence. Brinkema had been withholding them until the trial's end. The court acted in a lawsuit brought by nine news and reporters' organizations, including The Associated Press.

© 2009 CBS Interactive Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.
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