"The 2009 NRC-NAS report contained an assessment of hair analysis, says the manual, "observing that there are neither 'scientifically accepted [population] frequency' statistics for various hair characteristics nor 'uniform standards on the number of features which must agree before an examiner may declare a 'match'" The report concluded that "testimony linking microscopic hair analysis with particular defendants is highly unreliable," recommending DNA testing of the evidence where practical. Hair analysis is better at excluding suspects than individuating them: E.g., they could tell if someone had blonde with straight hair vs. curly hair from an African American, whether hair had been died, etc.. But even the best estimates of the technique's accuracy say the possibility of a false match is 1 in 4,500 for scalp hair and 1 in 800 for pubic hair. Other proficiency studies, have found much higher "false positive" rates - sometimes above 12%. Even more damning, an examination of the first 137 DNA exonerations found that 38% included invalid hair comparison testimony, with most of the cases involving "invalid individualizing claims.""
GRITS FOR BREAKFAST; "Grits for Breakfast says it "looks at the Texas criminal justice system, with a little politics and whatever else suits the author's (Scott Henson) fancy thrown in. All opinions are my own. The facts belong to everybody." Its motto: "Welcome to Texas justice: You might beat the rap, but you won't beat the ride."Reminder: Association in the Defence of the wrongly Convicted colloquium "Injustice Speaks"; Friday October 28, 2011;
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""Having recently examined advice being given to judges on how to interpret the science or lack thereof behind ballistics evidence, I thought I'd continue in that vein with a discussion of "microscopic hair analysis" from the same source (see the online version here, beginning on p. 112)," the Grits for Breakfast post published on October 27, 2011 begins, under the heading, "Forensic technique that was "judicially accepted for decades" called "highly unreliable".
"Both analyses are drawn from the third edition of the "Reference Manual on Scientific Evidence," produced by the Federal Judicial Center and the National Research Council of the National Academies of Science," the post continues.
"While microscopic hair evidence has been "judicially accepted for decades," says the manual, you can add it to the list as "another forensic identification discipline that is being reappraised today."
The 2009 NRC-NAS report contained an assessment of hair analysis, says the manual, "observing that there are neither 'scientifically accepted [population] frequency' statistics for various hair characteristics nor 'uniform standards on the number of features which must agree before an examiner may declare a 'match'".
The report concluded that "testimony linking microscopic hair analysis with particular defendants is highly unreliable," recommending DNA testing of the evidence where practical. Hair analysis is better at excluding suspects than individuating them: E.g., they could tell if someone had blonde with straight hair vs. curly hair from an African American, whether hair had been died, etc..
But even the best estimates of the technique's accuracy say the possibility of a false match is 1 in 4,500 for scalp hair and 1 in 800 for pubic hair.
Other proficiency studies, have found much higher "false positive" rates - sometimes above 12%. Even more damning, an examination of the first 137 DNA exonerations found that 38% included invalid hair comparison testimony, with most of the cases involving "invalid individualizing claims."
In the courtroom, prior to the US Supreme Court's Daubert opinion in 1993, "an overwhelming majority of courts accepted expert testimony that hair samples are microscopically indistinguishable."
However, 1990 decision in North Carolina held it an error to admit testimony that"it would be improbable that these hairs would have originated from another individual.".
The court held that such testimony amounted "effectively to positive identification of the defendant."
The first, significant post-Daubert challenge to such evidence came in Williamson v. Reynolds out of Oklahoma in 1995, where a district court was "unsuccessful in its attempt to locate any indication that expert hair comparison testimony meets any of the requirements of Daubert."
Before retrial, that particular defendant was exonerated by exculpatory DNA evidence. The section of the manual on microscopic hair analysis concludes:
"Both analyses are drawn from the third edition of the "Reference Manual on Scientific Evidence," produced by the Federal Judicial Center and the National Research Council of the National Academies of Science," the post continues.
"While microscopic hair evidence has been "judicially accepted for decades," says the manual, you can add it to the list as "another forensic identification discipline that is being reappraised today."
The 2009 NRC-NAS report contained an assessment of hair analysis, says the manual, "observing that there are neither 'scientifically accepted [population] frequency' statistics for various hair characteristics nor 'uniform standards on the number of features which must agree before an examiner may declare a 'match'".
The report concluded that "testimony linking microscopic hair analysis with particular defendants is highly unreliable," recommending DNA testing of the evidence where practical. Hair analysis is better at excluding suspects than individuating them: E.g., they could tell if someone had blonde with straight hair vs. curly hair from an African American, whether hair had been died, etc..
But even the best estimates of the technique's accuracy say the possibility of a false match is 1 in 4,500 for scalp hair and 1 in 800 for pubic hair.
Other proficiency studies, have found much higher "false positive" rates - sometimes above 12%. Even more damning, an examination of the first 137 DNA exonerations found that 38% included invalid hair comparison testimony, with most of the cases involving "invalid individualizing claims."
In the courtroom, prior to the US Supreme Court's Daubert opinion in 1993, "an overwhelming majority of courts accepted expert testimony that hair samples are microscopically indistinguishable."
However, 1990 decision in North Carolina held it an error to admit testimony that"it would be improbable that these hairs would have originated from another individual.".
The court held that such testimony amounted "effectively to positive identification of the defendant."
The first, significant post-Daubert challenge to such evidence came in Williamson v. Reynolds out of Oklahoma in 1995, where a district court was "unsuccessful in its attempt to locate any indication that expert hair comparison testimony meets any of the requirements of Daubert."
Before retrial, that particular defendant was exonerated by exculpatory DNA evidence. The section of the manual on microscopic hair analysis concludes:
Post-Daubert, many cases have continued to admit testimony about microscopic hair analysis. In 1999, one state court judicially noticed the reliability of hair evidence, implicitly finding this evidence to be not only admissible but also based on a technique of indisputable validity. In contrast, a Missouri court reasoned that, "without the benefit of population frequency data, an expert overreached in opining to "a reasonable degree of certainty that the unidentified hairs were in fact from" the defendant. The NRC report commented that there appears to be growing judicial support for the view that "testimony linking microscopic hair analysis with particular defendants is highly unreliable."RELATED: Go here to read the manual online or purchase a hardcopy. See also: Judges cautioned against reliance on overstated ballistics testimony.
The post can be found at:
http://gritsforbreakfast.blogspot.com/
PUBLISHER'S NOTE: The Toronto Star, my previous employer for more than twenty incredible years, has put considerable effort into exposing the harm caused by Dr. Charles Smith and his protectors - and into pushing for reform of Ontario's forensic pediatric pathology system. The Star has a "topic" section which focuses on recent stories related to Dr. Charles Smith. It can be found at:
http://www.thestar.com/topic/charlessmith
Information on "The Charles Smith Blog Award"- and its nomination process - can be found at:
http://smithforensic.blogspot.com/2011/05/charles-smith-blog-award-nominations.html
Harold Levy: Publisher; The Charles Smith Blog; hlevy15@gmail.com;
