ALEXANDRIA, Va. -- The FBI agent who arrested Zacarias Moussaoui weeks before the Sept. 11 attacks described yesterday how his superiors in Washington repeatedly blocked his attempts to learn whether Moussaoui was part of a cell about to hijack planes in the United States.
The FBI operative, Special Agent Harry Samit, said his superiors did not share critical intelligence information, including a memo from an FBI agent in Phoenix about suspected terrorists taking flying lessons, as well as a briefing for President Bush in which a warning that planes might be hijacked was given.
Furthering his frustrations, Samit said, was that his bosses told him right after two hijacked planes struck the World Trade Center that it was ''just a coincidence" with the case he was trying to make against Moussaoui.
Under cross-examination by defense lawyers in Moussaoui's sentencing trial, Samit said he believed his superiors were guilty of ''criminal negligence and obstruction."
He accused them of ''careerism," and said they had thwarted his efforts in order to protect their own positions within the FBI. ''They obstructed it," Samit said, calling their actions a calculated management decision ''that cost us the opportunity to stop the attacks."
Samit's recollections were the first ground-level account that FBI agents in Minneapolis, where Moussaoui was arrested on a visa violation 3 1/2 weeks before the attacks, had voiced their concern that their supervisors in Washington would not support their attempts to obtain critical search warrants to find out why the 37-year-old Frenchman of Moroccan descent, was taking flying lessons and what role he might have in a wider plan to attack the United States.
Samit's suspicions have been backed up by Coleen M. Rowley, who at that time was an FBI lawyer in Minneapolis. Rowley also has complained that Washington was blocking the Minnesota FBI field office's attempts to determine what Moussaoui was doing.
The prosecution has not sought Rowley's testimony, but government lawyers felt it essential to call Samit as a witness, because he could describe his arrest of Moussaoui and his efforts to get the defendant's cooperation.
The prosecution has asserted that, had Moussaoui cooperated with the FBI, agents could have learned of the hijacking plot and have taken steps to stop it.
As court adjourned yesterday, much of Samit's testimony may have backfired on the government. The jury easily could have been left with the impression of an FBI so at odds with itself that it not only missed critical clues of an impending terrorist attack but did not know how best to coordinate efforts to stop it.
Last April, Moussaoui pleaded guilty to being part of the Sept. 11 conspiracy. A jury now must decide whether he spends the rest of his life in prison or is put to death.
The sentencing trial began two weeks ago, but it was abruptly waylaid last week when it was learned that a lawyer for the Transportation Security Administration had improperly coached key aviation-security witnesses who were about to testify for the government.
When that lawyer, Carla J. Martin, would be called in to testify and explain her conduct remained uncertain yesterday. US District Judge Leonie M. Brinkema is allowing the prosecution to present a limited amount of aviation testimony and evidence in the case.
Prosecutors are trying to win a death sentence by proving that if Moussaoui had cooperated, the government would have used the information to identify some of the 19 hijackers and helped airport security officials keep them off the planes.
Defense lawyers maintain that the government itself had plenty of leads in summer 2001 that a major terrorist plot was afoot. They point to the FBI Phoenix memo and the fact that the CIA director at the time, George Tenet, was apprised of Moussaoui's arrest -- none of which, Samit said, was shared with him.
Samit said he also was kept in the dark about the Aug. 6, 2001, presidential daily briefing given to Bush during his vacation in Crawford, Texas. That briefing, titled ''Bin Laden Determined to Strike in US," noted ''patterns of suspicious activity in this country consistent with preparations for hijackings or other types of attacks."
''I didn't see it," Samit testified.
A defense lawyer, Edward B. MacMahon Jr., also used his cross-examination of Samit yesterday to suggest that officials didn't take such threats seriously at that time.
Samit said FBI headquarters in Washington rejected a series of attempts he made to obtain a search warrant of Moussaoui's personal belongings.
Had the belongings been opened before Sept. 11, 2001, agents would have found numerous small knives, jumbo-jet pilot manuals, rosters of flight schools, and other clues that could have helped them unravel the terrorist plot.