In their hurry to help find suspects in the March terrorist bombings in Madrid, FBI fingerprint examiners succumbed to top-down institutional intimidation and failed to correct an obvious blunder that led to the detention of an innocent Oregon lawyer, according to a panel of forensic experts.

"To disagree was not an expected response" within the FBI's bureaucratic culture, according to a report on the panel's findings. It said that once a supervisor in the agency's fingerprint unit had wrongly identified a print from the bombing investigation in Spain, "it became increasingly difficult for others in the agency" to tell him he had made a mistake.

The seven-member panel of international experts was assembled in June by the FBI to explore the reasons for the arrest of Brandon Mayfield, a Portland area lawyer and convert to Islam, which proved a major embarrassment in the Bush administration's war on terrorism. The report was published in the November-December issue of the Journal of Forensic Identification. The Justice Department is also investigating the case.

FBI agents detained Mayfield, 38, in connection with train bombings in Madrid that killed 191 and injured 2,000. Spanish investigators ultimately linked the bombing to al Qaeda and the mistaken fingerprint to an Algerian man, prompting the FBI to release Mayfield, who had been held for two weeks on a material-witness warrant. The FBI apologized for "the hardships this matter has caused."

The FBI blamed its error, in part, on the poor quality of digital fingerprint images provided by Spanish authorities. The expert panel, however, found that this assessment was not supported by the facts.

"All of the committee members agree that the quality of the images that were used to make the erroneous identification was not a factor," according to a synopsis of the panel's findings written by Robert B. Stacey, head of the quality assurance unit for the FBI's laboratory division.

His report added that when Spanish officials said the FBI was wrong, the fingerprint unit "immediately entered into a defensive posture."

Mayfield sued the federal government last month, alleging that his rights were violated because of his faith. Gerry Spence, a high-powered Wyoming lawyer and the lead plaintiff's attorney in the case, has not said how much money Mayfield is seeking in damages.

The civil suit alleges that the FBI had access to biographical information on Mayfield before its erroneous finding of a fingerprint match.

Steven Wax, who was Mayfield's criminal lawyer in Portland in the spring, said Monday that the panel's report is "tremendously significant" because it points to systemic problems with the FBI's fingerprint analysis techniques.

But Wax said that the panel did not explore whether FBI knowledge of Mayfield's life -- his Muslim faith or his work as a defense attorney for a Portland man who admitted trying to help the Taliban in Afghanistan -- might have predisposed the agency to use subjective fingerprint analysis as a way of linking Mayfield to the Madrid bombings.

"Is this a fingerprint mistake, or does it go beyond the business of fingerprinting with the contamination of the process with other information?" Wax asked.

The primary factor in the botched match was "human error" exacerbated by a shoddy system of peer review, the report said. After a supervisor made the initial mistake that linked a latent print to Mayfield, lower-level fingerprint examiners were afraid to rock the boat, the panel found. It concluded that these lower-level experts, when asked to verify the prints, should not have been permitted to know what a supervisor had concluded.

"The examiners should be encouraged to step forward, without fear of reprisal, if they disagree," the report said, strongly suggesting that this was not the case last March in the FBI latent print unit.

The print was found on a bag left in a van near a train station where three of the four bombed trains originated. Spanish police sent copies of it to other law enforcement agencies.

The panel recommended a major change in the way print examiners are assigned, especially in high-profile cases. Instead of allowing a supervisor to make initial findings, the panel said, rank-and-file examiners should be "the primary analysts."

In the bureaucratic culture of the FBI that existed last fall, the panel said, "a subordinate may not feel comfortable challenging the conclusion of a supervisor."

The panel's recommendations are likely to be reviewed by Congress. But in the meantime, according to Stacey, the quality assurance chief in the FBI's laboratory division, the agency is taking them seriously and "firmly believes that it will be made better as a result."

Brandon Mayfield is shown with his children in Portland, Ore., after being freed in May. Mayfield had been detained in connection with the March train bombings in Madrid.