This intrigues me. The suggestion here is that Sollecito employed the wrong expert. Can you briefly contrast the major points Professor Hampikian would have used during the trial with those of A. Tagliabracci--the actual expert they employed?
(Source:
http://perugiamurderfile.org/viewtop...p=17212#p17212 )
A side-by-side comparison and contrast would help us understand why the defence failed in refuting the prosecution evidence.
Did they hire the wrong expert?
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ETA: You are correct about other DNA on the bra clasp. I could probably find the cite at PMF but you're right.
[end quote]
I would like to respond to your request that I summarize the similarities and differences between the discussion of the DNA at the trial versus the petition coauthored by Professor Hampikian and Dr. Johnson. I found a link at the site you referenced to a report coauthored by Professor Adriano Tagliabracci (
http://www.istitutoaffarisociali.it...0a4daa67d625c63/indagini_genetico_forensi.pdf). Unfortunately, I do not speak Italian; therefore, I will not be able to execute your request as completely as I would like. Yet there are one or two references to RFU (relative fluorescence units) values of 150 and 50, and at least one reference to LCN.
I will try to summarize what I found on this long thread. Professor Tagliabracci found fault with the length of time (47 days) that the bra clasp was not in police custody. He criticized the number of times the clasp was handed from one technician to the next and put on the floor. He also specifically cited the insufficient changing of gloves and the touching of other objects as reasons to believe that cross contamination was possible. According to one poster, he “said ‘DNA has no wings, but can fly’ and may have been transported onto the bra with dust.” Elsewhere, his testimony alluded to the dust on the floor and the mat, which were under and over the clasp, respectively. He also brought up a “mis-interpretation of peaks” means the DNA on the piece of evidence is incompatible with Sollecito’s DNA.
The Perugia News Digest on 18 July 2009 reported the testimony
the examination of the bra-clasp followed incorrect protocols (4): in the collection of the evidence, in its analysis, and in interpretation (4): the evidence can be given no weight: ‘it cannot be considered as bona fide evidence” (4) “given the inappropriate and anomalous collection methodology” (3, 4) [end quote]
Many of these points are similar to those brought up in the petition. The petition claims that one cannot deduce how the DNA came to be on the clasp from how much is there. I do not know whether Professor Tagliabracci made this point or not. The only major objection Professor Tagliabracci raised that Professor Hampkinian did not is to question that the sample belonged to RS. Professor Hampkinian and Dr. Smith, on the other hand, do not seem to dispute that the DNA belonged to RS.
Although I could not find unambiguous reference to the knife in this thread, certain clues in the pdf document (references to RFU and LCN) suggest that he discussed it there. Professor Hampkinian’s petition treats the bra clasp and the knife with comments of roughly equal length. Professor Hampkinian, Dr. Smith, and their coauthors discuss the paradox of how the knife could be cleaned of DNA but not blood and express skepticism about whether this is possible. They also discuss the low signal-to-noise ratio of the peaks in the knife sample, the possibility of contamination, and the lack of publicly available .fsa files. Overall, I would describe the petition as covering more ground than Professor Tagliabracci, but I am not sure that the thread I read summarized all of his testimony, and I would like to know the contents of his report.
I do not have any reason to think that they hired the wrong expert. Please bear in mind that this comment is intended primarily as a summary; therefore, I suggest that people replying to this comment focus on whether it accurately summarizes the positions of Professors Tagliabracci and Hampkinian. I am particularly eager for people to address any omissions I have made or for someone to summarize Professor Tagliabracci’s report. A follow-up comment will be my attempt to evaluate the DNA data. Thank you for your patience when I attended to other matters.
Chris