Continuation Part 22: Amanda Knox/Raffaele Sollecito

[christianahannah]

The attached figure is from a 2011 paper by Bruce McCord and collaborators, "An Investigation of the Effect of DNA Degradation and Inhibition on PCR Amplification of Single Source and Mixed Forensic Samples. This electropherogram shows what happens when bleach (bottom panel) or hydrogen peroxide (middle panel) reacts with DNA but not to the point of complete destruction of the DNA. This confirms a prediction I made long ago, that the peak heights would get smaller, moving left to right in the electropherogram. In other words, the longer a piece of DNA is, the more likely that it will be damaged when a random agent acts upon it. Once it is damaged, it cannot be replicated by the polymerase chain reaction, leading to a smaller peak height. That prediction (which wasn't really much of a stretch) was based on work done on DNA degradation, some of which is discussed in Jason Gilder's Ph.D. thesis, chapter 3. The DNA from 36B, supposedly from the extraction of the knife, has peaks that vary in size, but I am unable to discern a clear downward trend. Therefore, it is difficult to argue that the kitchen knife was cleaned with bleach or hydrogen peroxide IMO.

This is interesting. In your reading of this thesis was there a difference in the downward trend of peaks whether the sample was a mixture or not a mixture? Would there be any difference in the downward trend of peaks whether the sample was fluid (i.e. blood) or solid (i.e. tissue)?

Also, in your viewing of the electropherograms did you see similar patterns between 36b and Amanda's sample on the knife (I do not have that reference ID before me)?

I hope you can understand how I am phrasing my questions. If not maybe some else could step in and help phrase it better.

 

[Bill Williams]

For Raff's DNA to realistically transfer from the door (say) to the bra clasp by a forensic glove, the original would need to be reasonably moist for the latex glove to pick it up (latex probably not very friendly towards preserving DNA) and then the glove to press down on the metal clasp fairly firmly. This stickability is enhanced by the lipids (fats) within sebaceous glands (mostly on the scalp and face), which also aids the impression of one's fingerprints.

It is highly vanishingly remote Raff's DNA would have survived on the door - in a moist, oily form - long enough for such a secondary transfer to take place. At his age, he likely was "a spotty youth" with lots of DNA carried in his sebaceous gland sweat, but it ain't necessarily so. There are lots of dry skin conditions, such as psoriasis, which would carry very little sebaceous lipids at all.

Why wear contamination counter-measures at all? It seems like that's your opinion because regardless you're going to suspect Raffaele and let the Scientific Police off the hook no matter what.

It's not just the door handle. Raffaele had been at the door trying to break it open. He was in the hall immediately outside the room.

Not 20 minutes later one of the postal police is in that room with no counter measures to see if Meredith is still alive. And if you don't believe Filomena's friend on that, perhaps you'll believe Monica Napoleoni that the whole of the police medical team went in there without counter-measures.

So your view is that counter-measures were unneeded, because the point is - contamination was unlikely, and the main thing is to convict the pair regardless.

No cole slaw for you.

 

[bagels]

This is interesting. In your reading of this thesis was there a difference in the downward trend of peaks whether the sample was a mixture or not a mixture? Would there be any difference in the downward trend of peaks whether the sample was fluid (i.e. blood) or solid (i.e. tissue)?

Also, in your viewing of the electropherograms did you see similar patterns between 36b and Amanda's sample on the knife (I do not have that reference ID before me)?

I hope you can understand how I am phrasing my questions. If not maybe some else could step in and help phrase it better.

He previously posted this on IIP:

I am unable to detect a downward slope in the hlectropherogram associated with the knife. There is variation in peak heights, but that is expected in a low template sample. In other words there is no reason to conclude that the DNA was degraded from 36B; there just was not much DNA.

 

[Stacyhs]

Would it have killed you to at least have had the Cole slaw delivered? The whole Stacyhs ex-beau barbecue was without cole slaw.

It ruined the coleslaw wrestling contest.

 

[Stacyhs]

I can't help but wonder why Vixen deleted four of her posts.

 

[Bill Williams]

I can't help but wonder why Vixen deleted four of her posts.

She was mad about the Cole slaw, too.

 

[Stacyhs]

She was mad about the Cole slaw, too.

It had to have been the coleslaw. It couldn't possibly be because of inaccurate statements.

 

[Vixen]

It had to have been the coleslaw. It couldn't possibly be because of inaccurate statements.

I just made a couple of soundtrack suggestions.

I fought the coleslaw and the law won.

 

[Chris_Halkides]

DNA degradation and the profiles from the knife

This is interesting. In your reading of this thesis was there a difference in the downward trend of peaks whether the sample was a mixture or not a mixture? Would there be any difference in the downward trend of peaks whether the sample was fluid (i.e. blood) or solid (i.e. tissue)?

Also, in your viewing of the electropherograms did you see similar patterns between 36b and Amanda's sample on the knife (I do not have that reference ID before me)?

I hope you can understand how I am phrasing my questions. If not maybe some else could step in and help phrase it better.

I will have to review his thesis and get back to you. He also wrote a chapter covering DNA degradation in a book, but I do not have that chapter. In one case of DNA mixtures (the 2008 paper on dust and DNA) there is a distinct downward slope to the peak heights IIRC.

When I discussed the issue of mixtures one time with Dr. Gilder, I suggested that it might be possible to determine that different profiles had degraded to a different extent and that this would provide a way to say whether or not a mixture was deposited simultaneously. He was resistant to this idea, but I don't recall his reasons, exactly.

In 36a and 36b we have to be aware of which loci are homozygous, because such a peak will be approximately twofold larger for that reason. I just glanced at 36A, and I think I see some evidence of downward sloping peaks. It would probably make sense to do the analysis in a more formal way, using linear regression and plotting the sizes of each fragment along the x-axis. It might be fun to try it with both peak heights and peak areas.

 

[Vixen]

DNA and law

Here's one for Samson. In the latest PRIVATE EYE 'Leave Special', there's a story in 'Funny Old World' about a case in Canberra Australia about a burglar who ransacked a café, stole the till, smeared diarrhoea all over the place and left a pair of soiled underpants, which forensic investigators matched to the DNA of one Wesley King.

The judge ruled: "DNA evidence taken from the waistband of the soiled underpants does suggest that Wesley King had worn them, and those underpants were found discarded at the scene of the crime. However, I am not satisfied that guilt is the only rational inference...[...]...For that reason, I find Mr King not guilty of all the charges'.

Mr King chose not to give evidence at the trial.

(Remind you of Raff?)

It shows that legal boffins can't get their heads around the fact DNA is physical evidence, not merely a debating point you can refute with a counter argument. Law is very much a humanities and arts subject with some logical skills required. However, when we consider the sheer ignorance of Hellmann and Marasca on the topic of DNA, we realise just how poles apart lawyers are from scientists.

 

[LondonJohn]

Here's one for Samson. In the latest PRIVATE EYE 'Leave Special', there's a story in 'Funny Old World' about a case in Canberra Australia about a burglar who ransacked a café, stole the till, smeared diarrhoea all over the place and left a pair of soiled underpants, which forensic investigators matched to the DNA of one Wesley King.

The judge ruled: "DNA evidence taken from the waistband of the soiled underpants does suggest that Wesley King had worn them, and those underpants were found discarded at the scene of the crime. However, I am not satisfied that guilt is the only rational inference...[...]...For that reason, I find Mr King not guilty of all the charges'.

Mr King chose not to give evidence at the trial.

(Remind you of Raff?)

It shows that legal boffins can't get their heads around the fact DNA is physical evidence, not merely a debating point you can refute with a counter argument. Law is very much a humanities and arts subject with some logical skills required. However, when we consider the sheer ignorance of Hellmann and Marasca on the topic of DNA, we realise just how poles apart lawyers are from scientists.

Once again, an abject inability to understand law, particularly in respect of inference.

A pair of soiled underpants were found at the scene of a burglary. DNA tests showed that King had worn those underpants.

Does that allow one to draw the inference that King was responsible for the burglary, and should that inference provide sufficient proof for conviction on a charge of burglary?

No.

There are other possible and feasible inferences that could be drawn. King could have arrived at the cafe after the burglary, for example. He could even potentially have arrived at the cafe before the burglary and left well before any burglary was committed.

In the absence of any other evidence that might, in the whole, constitute guilt beyond a reasonable doubt, King should be acquitted on the charge of burglary.

I think we're seeing, every day, just why Vixen's analysis of the Knox/Sollecito trials is so far off the mark...........

 

[LondonJohn]

Oh and in her aside of "Remind you of Raff?", Vixen once again illustrates her lack of understanding of the issues around testifying in one's own defence in a criminal trial, and why it's almost always a bad idea for ANY defendant (whether factually guilty or factually innocent) to take the stand.

There are some very good sources of information (legal reference documents, medico-legal psychology sources) that can explain all of this to Vixen and others.

 

[Desert Fox]

Oh and in her aside of "Remind you of Raff?", Vixen once again illustrates her lack of understanding of the issues around testifying in one's own defence in a criminal trial, and why it's almost always a bad idea for ANY defendant (whether factually guilty or factually innocent) to take the stand.

There are some very good sources of information (legal reference documents, medico-legal psychology sources) that can explain all of this to Vixen and others.

I know that the case where I was a juror, I did not think the prosecution had proven the case. If he had kept quiet and stayed off the stand, I would have voted to acquit.

 

[Vixen]

Once again, an abject inability to understand law, particularly in respect of inference.

A pair of soiled underpants were found at the scene of a burglary. DNA tests showed that King had worn those underpants.

Does that allow one to draw the inference that King was responsible for the burglary, and should that inference provide sufficient proof for conviction on a charge of burglary?

No.

There are other possible and feasible inferences that could be drawn. King could have arrived at the cafe after the burglary, for example. He could even potentially have arrived at the cafe before the burglary and left well before any burglary was committed.

In the absence of any other evidence that might, in the whole, constitute guilt beyond a reasonable doubt, King should be acquitted on the charge of burglary.

I think we're seeing, every day, just why Vixen's analysis of the Knox/Sollecito trials is so far off the mark...........

Once again, we see 'LondonJohn's' abject inability to understand scientific physical evidence. People think that because DNA is not visible to the naked eye, it is somehow an abstract concept, and not hard physical evidence.

Imagine, if at the scene of a crime, the perp left his mobile phone behind. It has happened that a conviction has followed for that person. Imagine police find your wallet at the scene. OK, you can argue, someone else could have transported it there. Now imagine a foot was found at the scene, of the perp. Police trace it to a someone whose DNA matches it (who has recently lost said foot). That is exactly the same scenario as Raff's 100% PERSONAL body tissue DNA left at the Kercher murder scene. Only Raff himself left it there, a surely as he left his calling card behind.

 

[LondonJohn]

Once again, we see 'LondonJohn's' abject inability to understand scientific physical evidence. People think that because DNA is not visible to the naked eye, it is somehow an abstract concept, and not hard physical evidence.

Imagine, if at the scene of a crime, the perp left his mobile phone behind. It has happened that a conviction has followed for that person. Imagine police find your wallet at the scene. OK, you can argue, someone else could have transported it there. Now imagine a foot was found at the scene of the perp. Police trace it to a someone whose DNA matches it (who has recently lost said foot). That is exactly the same scenario as Raff's 100% PERSONAL body tissue DNA left at the Kercher murder scene. Only Raff himself left it there, a surely as he left his calling card behind.

I guarantee that the ruling the Canberra court made was not on the basis (as you continue to believe in error) that there was no adequate proof matching the underpants to King (i.e that the court didn't properly understand the power and reliability of DNA evidence).

The ruling was (correctly) made on the basis that even though the underpants could be reliably matched to King, this did not in itself lead to the unequivocal and sole inference that King committed the crime. There were other potential reasonable inferences which were consistent with King not having committed the crimes with which he had been charged, and therefore King was (correctly) acquitted.

I'm sorry that you can't understand this. But that's the way it is.

ETA: you're equally wrong, albeit in a different way, in what you've written here about the alleged Sollecito DNA in the Kercher case ("Raff... left his calling card behind" and other ignorant nonsense). But I truly cannot be bothered telling you once again just how and why you're so wide of the mark.

 

[Bill Williams]

Oh and in her aside of "Remind you of Raff?", Vixen once again illustrates her lack of understanding of the issues around testifying in one's own defence in a criminal trial, and why it's almost always a bad idea for ANY defendant (whether factually guilty or factually innocent) to take the stand.

There are some very good sources of information (legal reference documents, medico-legal psychology sources) that can explain all of this to Vixen and others.

It's hard to believe this is Vixen posting. Reminds me of another poster who used to make these points.

Still, the poster in question says that it is Hellmann and Marasca who do not understand DNA. Yet there's Judge Massei in 2010 who wrote in his Motivations that the reason why the pillow semen-stain should not be tested is because "ownership" is irrelevant given that DNA cannot be timestamped....

..... but that Knox COULD be convicted on DNA evidence because her DNA in her own bathroom could have only got there the night of the murder.

Nencini wrote incomprehensibly about why, in his view, Stefanoni's DNA analysis should be considered immune from Vecchiotti's trashing of it, while then going on to say that contamination is irrelevant - so what that up to perhaps 5 male-DNA profiles were found in the single DNA sample on the bra-clasp, the point (how do you spell suspect centred) was that Raffaele's was found.

Oh sure. Hellmann and Marasca don't understand DNA. The poster, which is hard to believe is Vixen, does not give any examples, just asserts it.

 

[Bill Williams]

Just so that we can at least agree on what the Marasca/Bruno report said about the DNA evidence against K/S, this is how Marasca/Bruno systematically destroy any forensic-DNA interpretation which some use to convict them:

.....no trace of Sollecito was discovered in the room of the homicide. The only indicative element against him was represented by a trace of DNA discovered on the clasp of the victim's bra, the trace whose identification with this defendant was, however, excluded by the Vecchiotti-Conti report, which on this point, incorporated observations by the party's consultant, Professor Tagliabracci, a world-famous geneticist.​

Also erroneous was the reading of the results of the genetic tests performed on Exhibit 36 and on the presumed compatibility of the seized weapon with the most serious injuries detected on the victim's neck. In this regard, it was obviously a distortion by the judge a quo [of the trial from which this appeal is being heard], given that no DNA mixture of Kercher and Sollecito was found on the handle of the knife. On the same utensil, traces of starch were found, evidence that it could not have been thoroughly washed to remove incriminating traces. In addition, starch, present in plants, is well known for its absorbent capacity, therefore it would have absorbed blood if used to commit the homicide.​

the disproportional cruelty of the criminal action - could be considered as not being very compatible with any of the situations envisaged in the judgment, i.e. mere disagreements with Knox (which is even supported by evidence gathered from the victim’s mother), with sexual impulses of some of the participants and, perhaps, with the idea of a group sex game gone wrong. This however, was not reflected on the victim's body, beyond the digital violation by Guede, whose DNA was found in Kercher’s vagina.​

It is, rather, about ascertaining what value in the trial the genetic investigations can have when performed in a context when the analysis and findings are not at all respectful of the regulations approved by international protocols and those which, ordinarily, must take inspiration from the scientific method.

In making implicit reference to judicial interpretation of legitimacy, the judge a quo [of the trial from which this appeal is being heard] didn’t hesitate to attribute evidentiary value to the aforementioned results (f. 217).

The assumption cannot be shared.​

Marasca-Bruno also have a section on Italian law with respect to considering forensic-compatibility only, and the way "compatibility" should be factored into a decision, which M/B said Nencini erred in doing - according to the law.

Marasca-Bruno also cite the law with respect to improper handling of forensics - in my view a slap at not only Stefanoni, but the judges prior to the ISC who completely disregarded the issues raised with improper handling.

Marasca-Bruno then quotes from the Conti-Vecchiotti report on why "repeatability" is not only a scientific issue, but hence a legal issue.

(cf. Section 2, n. 2476 of 27/11/2014, dep. 2015, Santangelo, Rv. 261866, on the necessity of correct storage of the material containing genetic profiles, for the purposes of “repeatability” of technical findings capable of extrapolating the genetic profile; repeatability that is, moreover, dependent on the quantity of the trace and the quality of the DNA present on the biological exhibits collected; id. N. 2476/14 cit. Rv. 261867).

In the case in question, it is absolutely certain that those methods were not complied with (cf., among others, ff. 206-207 and the cited requested findings of the expert report Conte-Vecchiotti, ordered by the Perugian Court of Appeal).​

There's more. But this is why the poster in Vixen's last post is talking through his/her hat when criticizing Marasca-Bruno do not know how to handle the legal issues surrounding DNA.......

...... unless the person wishes to argue that things like repeatability is not a concept a court should concern itself with.

 

[Chris_Halkides]

36A may have more than one issue

Having discussed the matter with someone with more direct experience than I have, I would say that there is some degradation in electropherogram 36A, but there may have been one or more other problems as well. The peaks are fatter as the size of the fragments increases.

 

[Planigale]

For Raff's DNA to realistically transfer from the door (say) to the bra clasp by a forensic glove, the original would need to be reasonably moist

Unsupported assumption. Please see the posts by Halides showing transfer of DRY blood.

for the latex glove to pick it up (latex probably not very friendly towards preserving DNA) and then the glove to press down on the metal clasp fairly firmly.

Please reference evidence for latex not being 'friendly' towards preserving DNA?

This stickability is enhanced by the lipids (fats) within sebaceous glands (mostly on the scalp and face), which also aids the impression of one's fingerprints.

Actually DNA is sticky in itself.

It is highly vanishingly remote Raff's DNA would have survived on the door - in a moist, oily form - long enough for such a secondary transfer to take place.

The evidence for the DNA not surviving on the door handle, but surviving on the bra hook? You have created the straw man argument about the need for oil, there is no evidence that this is needed.

At his age, he likely was "a spotty youth" with lots of DNA carried in his sebaceous gland sweat, but it ain't necessarily so. There are lots of dry skin conditions, such as psoriasis, which would carry very little sebaceous lipids at all.

There are multiple possible routes of contamination of the bra hook by Sollecito's DNA, in addition to direct touch. Even direct touch is not proof of guilt.

The crime scene could have been better investigated. A particular example is no fibre analysis was done. If there had been the sort of struggle described there should have been fibre transfer. This was never looked for.

 

[Planigale]

Having discussed the matter with someone with more direct experience than I have, I would say that there is some degradation in electropherogram 36A, but there may have been one or more other problems as well. The peaks are fatter as the size of the fragments increases.

Do you mean AUC is greater, or the peaks are broader? (The two not being unrelated). Is there a peak height to peak width ratio one should look for?