An FBI agent testifying today at the death penalty trial of Zacarias Moussaoui says he warned senior officials about 70 times of fears that the confessed al-Qaida plotter planned to hijack an airliner.

Harry Samit, the agent who arrested Moussaoui, said he accused his superiors of “criminal negligence” and “careerism” when questioned during a U.S. government inquiry on Moussaoui’s role in the 9-11 plot, according to Agence France-Presse.

The agent’s testimony came as the death penalty trial resumed one week after Judge Leonie Brinkema threatened to throw out the prosecution’s case over witness tampering. Friday, Brinkema agreed to continue if prosecution lawyers use only uncontaminated witnesses.

Prosecutors, seeking the death penalty, argue Moussaoui lied to investigators, allowing the planned 9-11 attacks on New York City and Washington to go forward. The 37-year-old Frenchman is the only man tried in the United States over the attacks.

The defense insists the government had known much more about the 9-11 plot than Moussaoui but failed to take action to stop it.

If Moussaoui is not given the death penalty, he will spend the rest of his life in prison. He confessed last April to his role in the 9-11 plot.

In a memo presented by the defense during testimony, Samit warned that Moussaoui was an Islamic fundamentalist who believed in martyrdom, was learning how to fly a 747 jet and had a portable GPS navigation system, AFP reported. He also, the agent pointed out, was armed with small knives and learning martial arts.

Samit was questioned today about the memo, which he sent to FBI headquarters in Washington on Aug. 18, 2001, less than a month before the 9-11 attacks.

“You needed people in Washington to help you out?” Defense Counsel Edward MacMahon asked the agent.

“They didn’t do that, did they?”

Samit answered: “No.”

The agent said that when Moussaoui was arrested, he seemed to be in a hurry to finish his 747 flight training on a simulator in Minnesota.

“You wanted the people in Washington to know that because you were concerned that Moussaoui was going to try to hijack a plane right?” MacMahon asked Samit.

“Yes sir,” the agent replied.

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