Chris_Halkides
Penultimate Amazing
- Joined
- Dec 8, 2009
- Messages
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Fingernail DNA and Peter Gill's book
I agree that the writing is from someone who does not understand much about DNA. I skimmed the link to the decision itself that I found in one of the two links I provided, but there was not much more detail on the testing itself. Suppose that this were clearly a two-person mixture (no extra alleles and no missing alleles) with Penny Beernsten as one of the two donors. Then if Avery's profile matched some alleles but not others, he would still be excluded. Many people share a few alleles; therefore, such a possibility seems reasonable to consider.
The Wisconsin court seemed to be conceding that Avery was excluded, but arguing that the foreign DNA underneath Beernstein's fingernails could have come from casual contact and might not be from her assailant. "As such, the State contends that 'the DNA testing which excluded the defendant and the victim as the source of the DNA, really does not have much probative force in excluding the defendant as the assailant.'" This is possible, but it does not change the fact that foreign fingernail DNA is exculpatory with respect to a non-donor, because DNA from casual contact is known to be uncommon. Some time ago I wrote a summary of fingernail DNA studies, based upon Peter Gill's book, "Misleading DNA evidence." link.
I agree that the writing is from someone who does not understand much about DNA. I skimmed the link to the decision itself that I found in one of the two links I provided, but there was not much more detail on the testing itself. Suppose that this were clearly a two-person mixture (no extra alleles and no missing alleles) with Penny Beernsten as one of the two donors. Then if Avery's profile matched some alleles but not others, he would still be excluded. Many people share a few alleles; therefore, such a possibility seems reasonable to consider.
The Wisconsin court seemed to be conceding that Avery was excluded, but arguing that the foreign DNA underneath Beernstein's fingernails could have come from casual contact and might not be from her assailant. "As such, the State contends that 'the DNA testing which excluded the defendant and the victim as the source of the DNA, really does not have much probative force in excluding the defendant as the assailant.'" This is possible, but it does not change the fact that foreign fingernail DNA is exculpatory with respect to a non-donor, because DNA from casual contact is known to be uncommon. Some time ago I wrote a summary of fingernail DNA studies, based upon Peter Gill's book, "Misleading DNA evidence." link.
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