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Re: Back to basics testing your hypothesis.
Posted by:
Jim Mazerat (IP Logged)
Date: January 22, 2007 06:36PM
I am sure you are aware that hundreds of thousands of people have been convicted based on testimony from an expert on fingerprints. Do you remember the case of Brandon Mayfield, an Oregon lawyer, spent two weeks in jail in 2004 because three FBI experts matched his prints with those found on a plastic bag that was evidence in the investigation of the Madrid train bombings. He is grateful the Spanish authorities did not accept the FBIs findings as fact but continued to try to match the prints after the FBI arrested Mayfield and eventually linked them to an Algerian man. Does this mean there are two persons with the same print, or is there a problem with the identification methodology being used. Today examiners primarily rely on matching points on both prints where ridges end, bifurcate, or change direction. Examiners conclude a crime scene print came from a suspect after matching between three and sixteen points (FBI examiners found 15 points on Mayfields print). But there are no nationally reconized standards on the number of points that must be matched. Instead each lab, and sometimes each examiner, determines the number needed. If you complain about there being not accepted standard between the fire investigators,how do you now feel about the fingerprint expert that can send you to jail.
One known flaw in fingerprinting is that examiners may taint the identification process through bias and peer pressure. A panel of outside print examiners convened by the FBI to review the Mayfield case found that a supervisor made the initial identification and lower-ranking examiners, when asked to confirm or reject their boss work, felt pressured to confirm. Having FBI supervisors make the initial identifications was not unusual, according to Alan McRoberts, a retired Los Angeles County Sheriffs Department examiner and chair of the review panel, and other agencies do it as well. But while this practice resulted in one wrongful arrest, the panel did not recommend the FBI review other cases. As a committee, I dont think we discussed that in particular, said McRoberts.
All I am trying to say is that with our system there are many imperfections. I am not saying we should except anything less than the best but to only accept perfect may be saying there is nothing we can accept.
By the way, I do like the fact that you Denny and others here strive to reach the higher level of certainty.