Continuation Part Six: Discussion of the Amanda Knox/Raffaele Sollecito case

[Kaosium]

Bill have you seen the latest on RS's facebook the DNA results from the knife. The clean sample was run twice and was a match. RIS would prefer a second double test I know but those results! Combine that with the clasp ,short of DNA planted deliberately by a knowing investigator placed on the tip of her glove. A pre planned transfer??

Briars, there's absolutely no reason to believe the electropherogram indicates that DNA was ever on the knife. Stefanoni skipped or falsified the steps necessary to try to establish that, and then lied about it in court.

 

[Dan O.]

How much is needed for a complete profile?

How is it possible to have a partial profile in a mixed sample

 

[Kaosium]

Linda Geddes wrote an article called, "How DNA evidence creates victims of chance." One of the more interesting things is to see the ranges of numbers quoted, depending on which statistical method is used. Dr. Balding is quoted: "The 1 in 95,000 figure in effect treated these alleles as full-weight evidence that the DNA came from the victim, ignoring the alternative possibility that the allele we saw could have been from the defendant..." This issue also arises in the present case because Mr. Sollecito and Ms. Kercher share a large number of alleles.

There is also a little bit on discovery. "The problem is not confined to the UK. 'In our experience, examination of the underlying data frequently reveals limitations or problems that would not be apparent from the lab report,' says William Thompson of the University of California, Berkeley*, who acts as an expert witness on DNA. However, 'forensic DNA analysts tell us that they receive requests [for DNA lab reports] from defence lawyers in only 10 to 15 per cent of cases in which their tests incriminate a suspect,' Thompson says."
*Professor Thompson is from the University of California at Irvine, IIRC.

That is an interesting article. My opinion is that when they have a dominant profile to the extent that Meredith's was on the autosomal test, that when generating the likelihood of a match from someone else contributing they should ignore completely any potential shared alleles and not count them either way.

 

[Kaosium]

How is it possible to have a partial profile in a mixed sample

That can arise from damaged DNA or with low template samples. Some of the alleles can 'drop out' and this is a known problem they take into consideration whether the sample is mixed or not.

 

[Chris_Halkides]

completeness in a mixture is complicated

How is it possible to have a partial profile in a mixed sample

Consider the clasp. Meredith's profile is dominant, and she and Sollecito share many alleles (about 10 IIRC). How does one decide whether a peak corresponding to one of Meredith's alleles only has a contribution from her, as opposed to also having a contribution from Sollecito? Suppose that at a given locus, Meredith's profile is 16 repeats and Raffaele's is 15 repeats. If we see a peak at 15 is it from Raffaele, or is it only a stutter from Meredith? To some degree this question is addressed by using guidelines as to how big each stutter peak should be.

 

[Bill Williams]

The prosecution has always maintained that Rudy lies. That fact doesn't change the bigger lies and news lies by the other two defendants. It was a group crime.

No, Briars, it wasn't a group crime. They just arrested three people on evidence that turned out to be entirely bogus. That calls into question their competence and integrity, it doesn't serve as any proof that there were multiple people involved in the murder, just that they jumped to that unlikely conclusion on bogus evidence.

Even the prosecution experts had to admit there's nothing about the murder from the standpoint of forensic science that requires more than one attacker:

The consultants and forensic scientists have asserted that from the point of view of forensic science, it cannot be ruled out that the author of the injuries could have been a single attacker, because the bruises and the wounds from a pointed and cutting weapon are not in themselves incompatible with the action of a single person. With regard to this, it is nevertheless observed that the contribution of each discipline is specifically in the domain of the specific competence of that discipline, and in fact the consultants and forensic experts concentrated their attention on the aspects specifically belonging to forensic science: time of death, cause of death, elements indicating sexual violence, the injuries present on the body of the victim, and the causes and descriptions of these. The answer given above concerning the possibility of their being inflicted by the action of a single person or by more than one was given in relation to these specific duties and questions, which belong precisely to the domain of forensic science, and the meaning of this answer was thus that there are no scientific elements arising directly from forensic science which could rule out the injuries having been caused by the action of a single person.

You've missed Briars' point, Kaosium.

Briars' point is that if you go onto internet chat forums, like this one, and say, "it was a group crime" enough, then all of a sudden (regardless of what even Judge Massei said) it becomes a group crime.

And thus another factoid is born. This is how the guilter world establishes their "all the other evidence" factoids.

 

[Dan O.]

What? They didn't look at the browsing history? Those are time and date stamped. But it only shows when you entered a page. You could be composing an email for hours and it is only going to show when you opened the page.

The cache shows when you last visited a page. There were 4 interviewing days and we know that Amanda used Raffaele's computer to send email on one of those days. The cache would be overwritten.

 

[Dan O.]

That can arise from damaged DNA or with low template samples. Some of the alleles can 'drop out' and this is a known problem they take into consideration whether the sample is mixed or not.

But if you have one or more full profiles and you add a partial profile it will be indistinguishable from another full profile that overlaps the other full profiles. You can't zoom in on the peaks and see little cracks in them to know the DNA was damaged.

 

[Strozzi]

Consider the clasp. Meredith's profile is dominant, and she and Sollecito share many alleles (about 10 IIRC). How does one decide whether a peak corresponding to one of Meredith's alleles only has a contribution from her, as opposed to also having a contribution from Sollecito? Suppose that at a given locus, Meredith's profile is 16 repeats and Raffaele's is 15 repeats. If we see a peak at 15 is it from Raffaele, or is it only a stutter from Meredith? To some degree this question is addressed by using guidelines as to how big each stutter peak should be.

If Meredith's and Raffaele's DNA share about ten alleles, is it possible that the matter that Stefanoni claims she found on the blade of the knife from Raffaele's kichhen drawer is actually Raffaele's DNA, not Meredith's DNA?

 

[acbytesla]

The cache shows when you last visited a page. There were 4 interviewing days and we know that Amanda used Raffaele's computer to send email on one of those days. The cache would be overwritten.

I think it depends on the browser Dan. For example, Chrome shows me each time I visit a page. And this is the default cache setting.

But you can change the cache settings. You can have your browser clean out the cache frequently, in fact after every page visit so there would be no record.
IE works similarly. I have very little experience with Macintosh, so I couldn't say about Safari. There are also third party programs that manage your cache allowing you more flexibility than what is in Chrome and IE.

 

[christianahannah]

Consider the clasp. Meredith's profile is dominant, and she and Sollecito share many alleles (about 10 IIRC). How does one decide whether a peak corresponding to one of Meredith's alleles only has a contribution from her, as opposed to also having a contribution from Sollecito? Suppose that at a given locus, Meredith's profile is 16 repeats and Raffaele's is 15 repeats. If we see a peak at 15 is it from Raffaele, or is it only a stutter from Meredith? To some degree this question is addressed by using guidelines as to how big each stutter peak should be.

Mixtures are complicated. But doesn't the Y-haplotype test differentiate Raffaele's DNA from Meredith's DNA no matter how many alleles are shared?

 

[Kaosium]

Briars.... this is where you are just disingenuous.

My reading of even Judge Massei's analysis is that it was a single Y-Haplotype, which (rather than id'ing Raffaele) simply could have been half the Italian men in the courtroom, including Raffaele.

This is where halides1 needs to come into play here... or Kaosium.

Stefanoni performed (basically) two different tests on the bra clasp. The typical autosomal one and a Y-STR haplotype test that only shows DNA from males, which eliminates the problem of Meredith's DNA being so dominant and 'masking' evidence of other contributors. Massei relied on the Y-STR test which showed Raffaele's Y-haplotype, which isn't an exact match but is very suggestive Raffaele's DNA contributed to the sample the electropherogram was generated off of.

It was the autosomal test that, because it contained alleles from so many contributors, one could find a 'match' for roughly a quarter of the males in Italy or whatever it was they said, including judge Hellmann. Stefanoni's perfidy was to pretend most those alleles didn't exist and the sample only contained the alleles necessary to find Raffaele's and Meredith's profiles. She cheated and lied about it and did her best to hide it, which she's managed to continue to do until this day. What is available now is enough to determine her work was worthless, were the EDFs to be produced she might end up in prison.

However odds are that Raffaele's DNA contributed to those samples, what Stefanoni tried to hide is all the others who also contributed, prima facie evidence of contamination. It's not really a matter of her misinterpreting it, except in the sense she tried to pretend the others didn't also contribute.

There simply is no "complete profile of the victim" on the knife in any meaningful forensic sense.

That statement is true, but it's also true that Stefanoni produced an electropherogram that showed a complete profile of Meredith; the knife is not an interpretation issue either. That problem does arise with low template mixed samples (especially) but it's not what happened in this case.

However there's a whole lot more to forensic DNA work than simply producing an electropherogram that shows a complete profile! They also have to establish that electropherogram is indicative that the DNA actually came off the item sampled, and that DNA was on the item when the event (murder in this case) was committed and not the result of something afterward. It's also possible the DNA could have been there and the result of innocent transfer, which also has to be taken into account.

 

[christianahannah]

If Meredith's and Raffaele's DNA share about ten alleles, is it possible that the matter that Stefanoni claims she found on the blade of the knife from Raffaele's kichhen drawer is actually Raffaele's DNA, not Meredith's DNA?

Perhaps if the profile was partial and only comprised of those shared 10 alleles (if that is the correct number of shared alleles - this I don't know) but there was a full profile which Stefanoni attributed to Meredith and it was not a mixture.

 

[Grinder]

I think it depends on the browser Dan. For example, Chrome shows me each time I visit a page. And this is the default cache setting.

But you can change the cache settings. You can have your browser clean out the cache frequently, in fact after every page visit so there would be no record.
IE works similarly. I have very little experience with Macintosh, so I couldn't say about Safari. There are also third party programs that manage your cache allowing you more flexibility than what is in Chrome and IE.

Not withstanding the browsing history kept on the computer wouldn't there be a record of connections and length of those connection by the ISP?

Also if Raf was composing emails but not sending them immediately would records of that work be anywhere after the PLE fried the computers?

To be clear these are genuine questions.

From the ads I receive it is clear that someone knows where I've been. How many ranges do they think I'll buy?

 

[Supernaut]

Perhaps if the profile was partial and only comprised of those shared 10 alleles (if that is the correct number of shared alleles - this I don't know) but there was a full profile which Stefanoni attributed to Meredith and it was not a mixture.

Yes. Or maybe no.

Do will you EVER get to the point?

 

[Kaosium]

But if you have one or more full profiles and you add a partial profile it will be indistinguishable from another full profile that overlaps the other full profiles. You can't zoom in on the peaks and see little cracks in them to know the DNA was damaged.

This is why statisticians are necessary in the forensic DNA process, however it's not just a matter of statistics which is what I suspect Thoughtful believes. With a low template (especially) mixed sample you can't completely exclude anyone due to this factor, though obviously some will have greater likelihoods of contributing than others. Have you read Dr. Balding's paper on the clasp? He lays it out pretty well there, using the possibility of Amanda contributing as an example. Though keep in mind when he refers to it being 'strong evidence' regarding Raffaele he's referring to the statistical strength of Raffaele having contributed DNA to the sample the electropherogram was generated off of, and specifically notes that has nothing to do with how it got there.

 

[acbytesla]

Not withstanding the browsing history kept on the computer wouldn't there be a record of connections and length of those connection by the ISP?

Also if Raf was composing emails but not sending them immediately would records of that work be anywhere after the PLE fried the computers?
To be clear these are genuine questions.

From the ads I receive it is clear that someone knows where I've been. How many ranges do they think I'll buy?

Google, tracks your web searches and where you go and then tailors their advertising specifically to those searches. They sell this advertising and often place those ads on other company's websites.

If the hard drive where the cache is stored is fried, then there is nowhere to recover that data. Except if the ISP saves that data. Depends on the service provider and their practices. If you are online, then the connection is present all the time. But they can track searches, but not necessarily everything you do online. For example, they might track http but not https or FTP or another protocol, such as P2P.

But I'm not a computer forensics engineer. My knowledge on this subject is limited. There may be ways, checking administrative services and other files to note activity not seen in browsing history.

 

[Chris_Halkides]

It's Meredith's profile

If Meredith's and Raffaele's DNA share about ten alleles, is it possible that the matter that Stefanoni claims she found on the blade of the knife from Raffaele's kichhen drawer is actually Raffaele's DNA, not Meredith's DNA?

No, they don't share all alleles.

 

[Grinder]

Google, tracks your web searches and where you go and then tailors their advertising specifically to those searches. They sell this advertising and often place those ads on other company's websites.

If the hard drive where the cache is stored is fried, then there is nowhere to recover that data. Except if the ISP saves that data. Depends on the service provider and their practices. If you are online, then the connection is present all the time. But they can track searches, but not necessarily everything you do online. For example, they might track http but not https or FTP or another protocol, such as P2P.

But clearly they track searches and keep that data at Google. I am under the impression that history of online use is not just found in the computer's cache.

But I'm not a computer forensics engineer. My knowledge on this subject is limited. There may be ways, checking administrative services and other files to note activity not seen in browsing history.

Well I'm not arguing because I certainly don't know. I wonder if writing emails and not sending them would survive the PLE saute.

 

[Strozzi]

It might be a strong piece of evidence if the police hadn't lost it. Or if they'd collected it carefully & with clean gloves and not put it back on the floor. Or if they hadn't destroyed it for future DNA testing. Or if there hadn't been other profiles on it that remain unidentified. Of if they knew how it moved across the room. Or if they'd secured the crime scene. Or if they'd turned over all the testing records.

As it is, though . . . it's just sad reminder of what happened to Meredith. Raffaele had nothing to do with that.

I have overlooked an element to the case in my theory/accusation that Stefanoni made sure that Raffaele's DNA was on the bra clasp hook, as she would not make the expedition to Perugia with her entourage of assistants and videoographer and lighting guy to collect the clasp and then take it back to her lab in Rome only on the off-chance that it might have Raffaele's DNA on it. What I have overlooked is that she then destroyed the bra clasp by immersing the cloth and metal bra clasp in liquid. Destroyed it so that it cannot be tested by anyone else. It's like the tiny amout of matter (too low, too low) that she claims she found on the knife blade that was completely consumed in testing and therefore cannot be examined by anyone else.