FBI's lost chances in hunt for al-Qa'ida

Less than two weeks before the attacks of 11 September last year, an FBI agent asked his superiors to launch a hunt for one of the al-Qa'ida hijackers. When his request was denied he warned that "someday, someone will die" as a result.

The New York special agent asked senior officials in Washington on 29 August 2001 to begin an aggressive investigation into Khalid Almihdhar, who had recently entered the US and who would later help commandeer the plane that was crashed into the Pentagon, killing 188 people.

But lawyers in the FBI's National Security law unit refused the request, saying that information received through intelligence channels suggesting Mr Almihdhar was an al-Qa'ida terrorist could not legally be used to launch a criminal investigation.

"Someday, someone will die and – [legal] wall or not, – the public will not understand why we were not more effective and throwing every resource we had at certain problems," the agent said in a e-mail. The missed opportunity emerged on Friday when the agent, choking back tears and with a screen protecting his identity, gave testimony to the US House and Senate Intelligence Committee, which is holding hearings into the security failures surrounding the events of 11 September. .

It was just one of several clues missed by intelligence and law enforcement authorities before the attacks, the committee heard. Poor communications between the CIA and FBI and limited counterterrorism staff kept authorities from aggressively pur- suing two of the hijackers.

In her report, the inquiry's staff director, Eleanor Hill, painted a picture of missed opportunities. Individually, none might have prevented the attacks but collectively, they could have unravelled the plot.

These include the FBI's failure to follow up a memo by a Phoenix agent warning that US flight schools might be training terrorist pilots, and its refusal in August 2001 to pursue a warrant to search the computer of Zacarias Moussaoui, now charged with conspiring in the attacks.