A welcome exchange on the scientific status of fingerprinting

Abstract

Ten years ago, the notion that a top academic journal should publish an exchange on the scientific validation of fingerprint evidence would have been a non-starter. Until then, all but a few self-interested defendants and defence attorneys believed that when a fingerprint examiner matched a crime scene print (a latent print) to a suspect’s reference print, the evidence was absolute and irrefutable. A fingerprint match proved identity if not guilt. Today, however, scientists, attorneys and others are taking a hard look at the forensic sciences in general and fingerprint evidence in particular. The oft-repeated claims that fingerprints are unique and that the source of fingerprint fragments can be identified with certainty have received special attention. Balding (2005), Cole (2004) and Saks & Koehler (2008) argue against the uniqueness claim both in theory and in practice. Kaye (2003) points out the serious flaws in a study that some rely on as proof of fingerprint uniqueness. As for the certainty of fingerprint identifications, the data (not surprisingly) show that fingerprint examiners are fallible. Many commit false-positive and falsenegative errors in proficiency tests and in casework (Cole, 2005, 2006). Indeed, some critics argue that there is no scientific reason to believe that fingerprint examiners can make reliable identifications at all (Epstein, 2002). The scientific status of fingerprint identifications is brought into sharp focus by Drs Ralph and Lyn Haber in the target article that follows. As readers of this journal know, the US Supreme Court decision in Daubert v. Merrell Dow Pharmaceuticals (1993) allows proffered scientific evidence to be admitted in court only if the underlying technique is scientifically valid. Is the primary method used to analyse fingerprints (the ACE-V method) scientifically valid? The Habers argue that it is not. Shocking though it may be, no one has ever bothered to conduct a rigorous scientific experiment on ACE-V. The Habers detail what such an experiment should look like in light of the Daubert requirements. They conclude that fingerprint evidence be banished from the courtroom until the scientific validity of ACE-V is established. Three influential fingerprint scholars offer lively commentaries on the Habers’ paper. Professor Christophe Champod (University of Lausanne) argues that the shortcomings associated with ACEV have more to do with its transparency than its reliability. Professor Simon Cole (University of California Irvine) agrees with the Habers that the scientific validity of ACE-V has not been established, but fears that their policy recommendation will fall on deaf judicial ears. Professor Jennifer Mnookin (University of California Los Angeles) also agrees that ACE-V has not been validated through scientific tests, but argues that the Habers’ admissibility test is misguided. The Habers respond to these commentaries with characteristic gusto.