Over reliance on digital images of fingerprints led the FBI to wrongly suspect an Oregon lawyer of involvement in Madrid train bombings.
Muslim-convert Brandon Mayfield spent 17 days in detention after an FBI Lab wrongly linked him to prints recovered by Spanish police investigating the 11 March terrorist outrage. US authorities matched digital images of partial latent fingerprints obtained from plastic bags that contained detonator caps to Mayfield, leading to his arrest.
But last week Spanish investigators matched the fingerprints to an Algerian, forcing the FBI to admit it was wrong. A US court cleared Mayfield of all charges earlier this week. The FBI has apologised to Mayfield and his family for the blunder and issued a statement promising to review procedures.
The statement said: "The FBI identification was based on an image of substandard quality, which was particularly problematic because of the remarkable number of points of similarity between Mayfield's prints and the print details in the images submitted to the FBI. The FBI's Latent Fingerprint Unit will be reviewing its current practices and will give consideration to adopting new guidelines for all examiners receiving latent print images when the original evidence is not included."
The FBI maintains it followed industry guidelines but this assertion is undermined by reports that US investigators were dismissive to Spanish requests to double check their findings. The New York Times reports that "FBI officials were so confident of a match they... never bothered to look at the original print while they were in Madrid on April 21 to meet with Spanish investigators".
The Madrid attacks killed 191 and injured hundreds more. The suspected mastermind of the atrocity, Serhane ben Abdelmajid Fakhet, blew himself and another four suspects up during a police raid on 4 April. ®