I read the link above to the C&V report above and now have a head ache.
Am I reading it correctly in that its saying Raf's DNA was found but because of the procedures used and risks of contamination, it can't be concluded that Raf's DNA was not there because of contamination?
It didn't sound like they were saying it wasn't Raf's DNA or a Y-?? compatible with in 4 males like I thought I read upthread. Is this correct?
Conti and Vechiotti just say 'several.' There's no reason for them to calculate it, though it can be figured from their work, and had been already by DNA experts. There's at minimum four contributors to the clasp and likely five and possibly more, though keep in mind one of those is Meredith, who won't be shown on the y-haplotype.
thanks for any help you can provide in aiding me to wrap my head around the language and jargon of this subject matter
If you're interested, I ended up writing quite a bit, but for quick answer to your question,
here's one of the things that Stefanoni was trying to hide, it's linked on the previous page which I detail a little bit below as well. If you look at that chart, on the left that's what Stefanoni turned in at the beginning of the trial regarding the y-haplotype analysis of the bra clasp. On the right is the actual alleles as assessed by Conti and Vecchiotti, the independent court experts. As this is a y-haplotype there's generally going to be just one allele in each location (loci). However as it's also a Y-haplotype there's going to be 'linkage' as some alleles kind of come together, meaning a person who has one may have another that will be the same (down the list) which will also be present with it, reducing variability. That's unlike an autosomic test, which is what most consider 'DNA testing.' Those are all individual which is why they are so varied and can produce probabilities within millions or billions. That's not the case with a y-haplotype.
There's also going to be overlap, meaning the same allele is shared by more than one person in the mixture, as you can see all contributors to the clasp have alleles at DS9389II, DYS439, DS913 and DYS392, though that can also happen through 'droppage' meaning an allele just doesn't show up. However as y-haplotypes are often heavily regionally dependent, a number having the same alleles is not unusual. As there's three loci with three alleles there's a minimum of three male contributors to the clasp. However due to 'droppage' and
'linkage' as well as the likelihood many share alleles, there's probably at least one and possibly more, there's a way of figuring it by the ones most commonly associated ('linkage') and the rarity of certain ones appearing with others. In this case it was considered most likely there was four males on the clasp.
That was the summary of her technical report, their report on that is on the previous page,
here. Note that it's
not saying Raffaele's DNA was found, that was impossible to determine with the autosomic test, what they say here is that Raffaele's Y-Haplotype can be put together if they take the largest of the Y-Haplotype peaks, which is no guarantee that they all came from the same person, but at least she's consistent here.
As Dan-O pointed out, this Y-Haplotype has to be pieced together, and as there's at absolute minimum three males on the clasp, to use a different analogy that's like having fifteen cards instead of five to put together a poker hand, makes it quite a bit easier, especially as the Y-Haplotype is not nearly as variable as the autosomic, which is what they use for DNA profiling to get, under the best of circumstances, a match within billions.
This is nowhere
close to that level, as the Y-haplotype is not nearly as variable as the autosomic, in fact it's guaranteed that there will be others with the same, notably ones male ancestors and pretty much all their descendents going back many generations, thus it's heavily regionally dependent. However establishing the specific Y-haplotype is not an exact science and when you have several contributors a profile can be put together for someone who didn't contribute any DNA at all! However being as Stefanoni was consistent, C&V allow that the Y-haplotype profile she generated matches Raffaele's.
It's not certain as Dan-O said, and a result like this would require reproducibility because even relatively smaller contributors can have alleles with variable values, and if just ONE of those is responsible for a peak not generated by the otherwise larger one (which is not that unusual) then the Y-haplotype is not Raffaele's. Therefore it should be repeated, which was not done. When Professors Conti and Vecchiotti went to re-test this clasp they found that in a mere eighteen months it had deteriorated due to improper storage in plastic, which as I posted before she testified before Massei specifically that storing them in plastic would retard their usefulness.
However, they allow that the Y-haplotype profile generated is probably Raffaele's,
because it doesn't really matter. She had something to hide, tried to hide it, and Judge Hellmann insisted she turn over her files to the Court-appointed independent experts, which she
still refused to do in totality, but the good professors found they had all they needed...to
rake her over the coals.
Her malfeasance was pronounced and profound, not little things, though they found those too, (and were not shy about pointing them out!) but incredibly important things starting with her not even
bothering to try identify the substance on the clasp, she just 'presumed' it was skin cells and didn't even
attempt a blood test, which is very strange as establishing what kind of biological material is certainly more damning that her saying she's guessing and didn't even try. If you want to learn something about this process to get an overview, read pages 4-12 of
this, which is an FBI special report regarding DNA analysis,
ironically enough regarding a little lab tech caught gundecking her negative controls. (Stefanoni refused to turn those over too)
However for now just turn to page 8, (22 of the pdf) and look at the flow chart for DNA analysis. As you can see the very first step is testing for a biological substance. As you can also see if the answer is 'no' that's the end of your DNA analysis, it doesn't happen. On this item Stefanoni simply chose to 'presume,' and did no tests whatsoever. One reason this is important is because the DNA amplification process in a lab will generate millions upon billions of copies of DNA, but
not any biological substances. Being as her lab wasn't even certified for regular DNA work, (though it was equipped--it was awaiting certification at the time of the first trial) it most certainly wasn't qualified to be doing
LT/LCN DNA work, as with that the risk of contamination and faulty analysis is far greater. A well-run lab with stringent protocols is going to get contamination, but the safeguards in place minimize the risk of error. If you don't follow those safeguards you have an entirely different situation, and if you don't even pretend to try hard (but testify in court that you do!) the risk is far greater, especially working with LCN/LT DNA.
Now, back to the Y-haplotype. Somewhere I read in passing that TJMK was pretending that a y-str haplotype test would match only one's father or somesuch. That's not even
close to true, it goes back much farther than that, just how rare they are has not been determined as the database is incomplete, but there is enough data to get an idea. I checked and
Raffaele's is not in the database yet but I did find
an abstract for a paper regarding studies done in Italy:
Abstract from Forensic Science International: Genetics Volume:6 Issue:6 Dated:December 2012 AF. Brisighelli et al said:
The 17 Y-chromosomal short tandem repeats (STRs) included in the AmpFlSTR Yfiler Amplification Kit (AB Applied Biosystems) (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385ab, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635 and GATA H4.1) were typed in 292 samples from 7 Italian regions.
Abstract: Population comparisons with other European samples were undertaken; for this purpose, 2 databases were collated from the literature: (a) 19 population samples including greater than 2,900 Yfiler profiles, and (b) 67 population samples including greater than 15,000 minimum haplotype profiles. A total of 276 different Yfiler haplotypes were observed in Italy, and only one of them was shared among 7 population samples. The overall haplotype diversity (0.9996) was comparable to other European samples. AMOVA indicates that among population variance depends on the amount of Y-STRs used, being higher when using minimal haplotypes. This is probably due to the fact that Yfiler profiles are represented by singleton haplotypes in all the population samples raising the diversity values to the maximum theoretical value. AMOVA results seems to depend even more strongly on the amount of population samples used, the among population variance in Italy ranging from 2.82 percent to 11.03 percent (using 15 and 32 Italian populations samples, respectively). Variance is not as strongly stratified geographically within Italy, although it is notorious that latitude is more important than longitude in the distribution of variance. The results also indicated that Italy is less stratified than other European samples. The present study contributes to enrich the Y-chromosome databases regarding high-resolution Y-chromosome data sets and demonstrates that extended Y-STR profiles substantially increases the discriminatory capacity in individual identification for forensic purposes.
So basically amongst a sample of 17,900 they found 276 separate haplotypes, so there's far more than just one's father and near male relatives, but still there's many of them and they've not all been mapped out, however the progression here won't be linear as odds are as more people are added, more and more will have the already mapped y-haplotypes so you can't just divide 17,900 by 276 and figure that's the likely progression, if you noted from the database there's actually only ~1600 or so in all of Europe that they've mapped, which is an indication of how the probability might progress as each haplotype added reduces the odds of adding a new one. Also this is heavily regionally dependent, so it's far more likely that Raffaele will share not only a haplotype, but also the 'numbers' generated will be similar, and thus in determining the profile there's a greater chance of overlap.
However as I noted it's
probable in my mind that the Y-haplotype on the bra clasp indicates that's Raffaele's DNA, but what really matters is whether that DNA on the bra clasp means Raffaele's DNA was deposited in the process of him being involved in the murder of Meredith Kercher, and that is a resounding 'No' from Professor's Conti and Vecchiotti, as so
many avenues of contamination and transfer, which we
know definitely occurred due to other profiles on the clasp.
Here's there final conclusion on the clasp:
C&V Conclusions said:
Relative to Item 165B (bra clasps), we find that the technical analysis is not reliable for the following reasons:
1. There does not exist evidence which scientifically confirms the presence of supposed flaking cells on the item;
2. There was an erroneous interpretation of the electrophoretic profile of the autosomic STRs;
3. There was an erroneous interpretation of the electrophoretic profile relative to the Y chromosome;
4. The international protocols for inspection, collection, and sampling of the item were not followed;
5. It cannot be ruled out that the results obtained derive from environmental contamination and/or contamination in some phase of the collection and/or handling of the item.
Not reliable means
junk and that's true on so many levels it's actually evidence against the prosecution. In court Conti and Vecchiotti walked through a reading of the manuals and the testimony of the police on how they were supposed to, and had said they did their work, and then showed the jury the videos of how they actually did it to gales of laughter.