WASHINGTON -- The Federal Bureau of Investigation wrongly implicated an Oregon lawyer in a deadly train bombing in Madrid because the F.B.I. culture discouraged fingerprint examiners from disagreeing with their superiors, a panel of forensic experts has concluded.
“The error was a human error and not a methodology or technology failure,” the panel said in a report on the arrest of the lawyer, Brandon Mayfield of Portland, who was jailed for two weeks in May. “Once the mind-set occurred with the initial examiner, the subsequent examinations were tainted.”
“To disagree was not an expected response,” said the report, written by Robert B. Stacey, head of the quality-assurance unit of the bureau’s laboratory division at Quantico, Va. He said the first, and as it turned out, erroneous conclusion about the fingerprint had not been sufficiently scrutinized.
Mr. Stacey conducted the inquiry with an international team of forensic experts. Its findings were published in the November-December issue of The Journal of Forensic Identification and reported in The Chicago Tribune on Sunday.
In an episode that acutely embarrassed the bureau and prompted an official apology, Mr. Mayfield came under suspicion in the March 11 bombing, which killed 191 people and injured about 2,000, because of a fingerprint misidentification.
Five days after the bombing, the Spanish police sent photographs of several prints found on a plastic bag near the attack scene to law enforcement agencies in the United States, Britain and France. The F.B.I. notified federal authorities in Portland that a Madrid fingerprint matched one of Mr. Mayfield’s, on file from his Army service years before.
Mr. Mayfield’s home was searched and he was imprisoned as a material witness. The lawyer, a convert to Islam, has accused the federal authorities of leaping to conclusions because of his religion and his ties to Muslims in Oregon.
The F.B.I. has denied the accusations and apologized for its mistake. The bureau issued a statement on Tuesday expressing its appreciation for the study and saying it was reviewing “every aspect’’ of its fingerprint-analysis process.
Mr. Mayfield is suing the federal government on the ground that his rights were violated because of his religion. The original lawyer, Steven Wax, called the forensic experts’ investigation “tremendously significant” because it points to basic flaws in F.B.I. fingerprint analysis.
The Justice Department is doing its own internal investigation.