6,835,000 pageviews


Thursday, April 13, 2023

The Madrid Bombing Case: Fingerprint Misidentification

     On March 11, 2004, terrorists in Madrid Spain bombed a passenger train, killing 191 people. The Spanish National Police sent the FBI digital images of eight latent prints found at the bomb site. These images were fed into the FBI's Integrated Automatic Fingerprint Identification System (IAFIS), a $640 million supercomputer housed in Clarksburg, West Virginia. The computer selected from its collection of 48 million fingerprints sets, 15 digital latent images as possible matches. Three FBI examiners matched one of the 15 possibles to a latent from Spain that had been left on a plastic bag containing bomb detonators. The FBI experts believed this print belonged to a 37-year-old lawyer from Portland, Oregon named Brandon Mayfield.

     If the FBI fingerprint experts were correct, Brandon Mayfield had been at the scene of the Madrid bombing. The fact that Mayfield, a former Army lieutenant who had converted to Islam heightened the FBI's suspicion that he had been involved in the deadly bombing.

     Fingerprint examiners in Spain agreed that Mayfield's print and the crime scene latent shared eight points of similarity, but the numerous dissimilarities kept them from declaring a match. The FBI responded by having a fourth bureau expert look at the evidence, and he too, declared a match. Shortly thereafter, FBI agents arrested Brandon Mayfield. In the meantime, the police in Spain announced that the crime scene latent belonged to an Algerian suspect named Ouhane Daoud.

     A team of FBI fingerprint experts traveled to Madrid and when they compared Mayfield's fingerprint to the actual latent they realized their mistake. Blaming the misidentification on the low-resolution image of the digital print, the FBI apologized to Mr. Mayfield. However, when a panel of fingerprint experts reviewed the evidence, they found that the misidentification had nothing to do with the quality of the digitized latent. The four FBI experts had simply overlooked easily observed dissimilarities between the two prints.They allowed their eagerness to identify a terrorist override their scientific objectivity. There may also have been an element of groupthink in the misidentification.

     Brandon Mayfield filed a lawsuit, and in November 2006, the federal government agreed to pay him $2 million in damages. The Justice Department augmented the settlement with an official apology, stating that misidentifications of this nature were rare. University of California at Irvine professor Simon Cole disagreed. Responding to news of the settlement, he told a Los Angeles Times journalist that "this is a tip-of-the-iceberg phenomenon. The argument has always been that no two people have fingerprints exactly alike. But that's not what you need to have an error. What you need is for two people to have very similar fingerprints and that's what happened here."

    For years, when FBI experts testified in criminal trials they claimed that in the history of the bureau there had never been a fingerprint misidentification. They could no longer make this claim which was never true. Moreover, in the wake of the Madrid bombing case embarrassment, the FBI fingerprint examiner proficiency test came under attack. According to a FBI whistleblower, if the test was not so ridiculously easy,cheating would be commonplace.

     While juries and the American public believe deeply in the reliability of fingerprint identification, it is not hard science, and there will be identification mistakes.

1 comment: