Continuation Part 3 - Discussion of the Amanda Knox case

[shuttlt]

shuttlt,

Where do your 1 in 1000 odds come from?

I made it up based at least in part on my own feeling that people often over estimate the improbability of things. I'm not claiming that these are the odds, just that based on my own level of ignorance I'm not willing to assume that the odds are worse than this.

10% bleach is specifically mentioned in the Conti-Vecchiotti report, BTW.

Fair enough.

I am still waiting to hear from you how DNA can remain on the knife without magical cleaning fluid. I have been waiting for someone to answer this in a sensible way since December of 2009.

God knows. I'm not a magic cleaning fluid expert. I don't know whether bleach was used. If bleach was used I don't know what concentration or for how long.

 

[Chris_Halkides]

Osmotic Shock redux

What claim am I making? Halides asserted that it is win the lottery twice unlikely. I asserted that I personally find it hard to believe the odds are worse that 1,000 to 1 against. I can back the assertion that this is my own personal opinion with as much survey data as you would like me to provide. If Halides's view is based on no more than his own personal hunch then that's fine by me.

shuttlt,

You gave odds of 1 in 1000. My perception of the odds is based on the 1998 Biotechniques article which discussed the properties of bleach as an aid in destroying DNA. There is also a good Promega technical bulletin on the matter. Perhaps I should have reserved astronomical odds for the case in which bleach is the supposed cleaning agent. However, I still cannot conceive of how cells won't be disrupted via osmotic shock, no matter what cleaning agent one uses. Maybe you can explain how, since the theory that the knife is the murder weapon implies it.

 

[shuttlt]

-

That it's more likely 1,000 to 1, than 2 trillion to 1. You can't fairly ask for research to back up his opinion and then unfairly offer your own opinion as more likely with no research to back it either.

You should not have asked for research to back one opinion without offering the research to back your own, that's my point and also just my opinion,

Dave

If somebody else says that such and such IS the case and other people who think different ARE wrong, then I ask for research. If you want to say that you personally happen to believe that something is the case, then I am quite content for you not to have any desperately compelling basis for that.

 

[shuttlt]

shuttlt,

You gave odds of 1 in 1000. My perception of the odds is based on the 1998 Biotechniques article which discussed the properties of bleach as an aid in destroying DNA. There is also a good Promega technical bulletin on the matter. Perhaps I should have reserved astronomical odds for the case in which bleach is the supposed cleaning agent. However, I still cannot conceive of how cells won't be disrupted via osmotic shock, no matter what cleaning agent one uses. Maybe you can explain how, since the theory that the knife is the murder weapon implies it.

I freely admit that I can't. I am also well aware that you are more knowledgable than me on this.

 

[Chris_Halkides]

diluted bleach

God knows. I'm not a magic cleaning fluid expert. I don't know whether bleach was used. If bleach was used I don't know what concentration or for how long.

shuttlt,

Yet you have said that the most likely way for the DNA to transfer is for direct contact to have occurred, and the the only reasonable way for that to happen is for the knife to be the murder weapon. I would think that anyone proposing this must make himself or herself an expert in magic cleaning fluid.

With respect to the concentration of bleach, it almost does not matter. The first officer to collect the knife claimed to smell bleach. Does that mean that bleach was still on the knife in his tale? That is how I take it. The Promega bulletin noted that a 2-3% bleach solution is often used to make pipets free of unwanted DNA. But the authors caution that one must then thoroughly rinse the bleach away, or the residual bleach will destroy the DNA of interest. In other words a dilution of dilute bleach is enough to destroy DNA.

 

[AmyStrange]

If somebody else says that such and such IS the case and other people who think different ARE wrong, then I ask for research. If you want to say that you personally happen to believe that something is the case, then I am quite content for you not to have any desperately compelling basis for that.

-

Just curious, but isn't "survey data" just another way of saying "opinion poll"?

Read halides1 "research basis" above your post, but I do see your point in the post above. It is a valid point,

Dave

 

[Rolfe]

Ms. Stefanoni tested the knife in many spots, not just one.

And only one produced the Meredith profile.

This massively supports the "contaminated in the laboratory" theory. If there is DNA of Meredith's in the lab, then the chance of it happening to contaminate the only sample from the knife seems like a big coincidence. But the more samples you test, the better the chance that one of them will pick up a low level contamination.

Suppose the contamination was only affecting one sample in ten. And it was such a low level you'd need LCN techniques to see it. And of course if a sample which really had Meredith's DNA on it was affected, it would be impossible to tell.

In this context, pointing out that other samples tested didn't show Meredith contamination is almost irrelevant. You'd need to be looking at samples that didn't have her DNA on them in the first place, and then you'd have to crank the sensitivity right up as was done with the knife, and then you're only going to see it in 10% of the samples.

No wonder Novelli couldn't immediately lay his hand on another example....

Rolfe.

 

[shuttlt]

shuttlt,

Yet you have said that the most likely way for the DNA to transfer is for direct contact to have occurred, and the the only reasonable way for that to happen is for the knife to be the murder weapon. I would think that anyone proposing this must make himself or herself an expert in magic cleaning fluid.

Again, this is widening the question beyond the limits that I set, or at any rate intended to set, on my answer. If you include and exclude parts of the case the odds change.

With respect to the concentration of bleach, it almost does not matter. The first officer to collect the knife claimed to smell bleach. Does that mean that bleach was still on the knife in his tale? That is how I take it.

But it doesn't need to be.

The Promega bulletin noted that a 2-3% bleach solution is often used to make pipets free of unwanted DNA. But the authors caution that one must then thoroughly rinse the bleach away, or the residual bleach will destroy the DNA of interest. In other words a dilution of dilute bleach is enough to destroy DNA.

There is presumably a half life for the DNA at particular concentrations? Is it enough to simply say at 2% dilution there will be no DNA regardless of any other factors?

 

[shuttlt]

-

Just curious, but isn't "survey data" just another way of saying "opinion poll"?

Certainly, but given that my claim was about an opinion and I would easily be able to survey 100% of the population it would be a valid approach.

 

[Rolfe]

Investigation desperately needs some forensic evidence tying Knox and Sollecito to the crime. Items from the cottage are problematical, because either of their DNA might have got there innocently.

So they ignore all the knives right there beside the body, and go to Sollecito's flat. There they pick one kitchen knife of several, for no readily apparent reason, ignoring others. Even though it doesn't match either the bloody impression or the wounds. This single knife is tested in multiple spots, and when the machine can't find any readable DNA, Stefanoni turns up the sensitivity to LCN levels, even though the lab has handled high-copy-number DNA of Meredith's and none of the proper procedures for testing LCN DNA were followed.

One of these samples turns up a tiny tiny amount of Meredith's DNA.

For God's sake, why do you even bother considering other ways that profile might have got there?

Rolfe.

 

[AmyStrange]

Certainly, but given that my claim was about an opinion and I would easily be able to survey 100% of the population it would be a valid approach.

-

Hehehe. You're OK in my book Shuttlt. I don't care what they say about you on PMF and TJMK,

Dave

 

[AmyStrange]

Gawd...

Investigation desperately needs some forensic evidence tying Knox and Sollecito to the crime. Items from the cottage are problematical, because either of their DNA might have got there innocently.

So they ignore all the knives right there beside the body, and go to Sollecito's flat. There they pick one kitchen knife of several, for no readily apparent reason, ignoring others. This single knife is tested in multiple spots, and when the machine can't find any readable DNA, Stefanoni turns up the sensitivity to LCN levels, even though the lab has handled high-copy-number DNA of Meredith's and none of the proper procedures for testing LCN DNA were followed.

One of these samples turns up a tiny tiny amount of Meredith's DNA.

For God's sake, why do you even bother considering other ways that profile might have got there?

Rolfe.

-

quit being so damn logical Rolfe! You're ruining it for the rest of us! Hehehe,

Dave

 

[AmyStrange]

quit being so damn logical Rolfe! You're ruining it for the rest of us! Hehehe,

Dave

-

It's just as bad as giving out "spoilers" to a movie. It's just so inconsiderate to the rest of us who haven't seen the end this movie yet or snuck a peak to the back of the book to see who done it. Sheeesh,

Dave

 

[LondonJohn]

In all the discussion over the past couple of pages, I think that Shuttlt is consistently forgetting one absolutely crucial thing: there is a massive (and correctly so) asymmetry inherent in a criminal trial which is adversarial rather than inquisitorial*. In order for Knox and/or Sollecito to be found guilty, the court must conclude that there is overwhelming evidence of their participation in the murder: in fact, the court must reason that there is no doubt (based in human reason) that Knox and/or Sollecito participated in the murder. Anything less than total proof must result in acquittals.

Therefore, all the discussion about the knife and the "confession/accusation" must be viewed in that context, if one is to discuss these issues in any meaningful way. I know that some people here are on a "search for the truth", but I still contend that a) this is probably going to be forever impossible to know for sure, and b) of only very limited relevance to the trial process of Knox and Sollecito. The only thing that is both relevant and testable is whether there is proof positive that Knox and/or Sollecito participated in the murder of Meredith Kercher. Anything less than that is effectively the null hypothesis.

Therefore my position (and the one the court should adopt) on the "confession/accusation" and the knife/bra clasp is that since there are entirely feasible ways to explain them from an innocence standpoint, they therefore carry very little weight for proving guilt. The question is not one of how conclusively one can "prove" how and when contamination occurred, nor how conclusively one can "prove" that Knox was coerced into a false confession/accusation. The fact is that both these things are very real possibilities, and therefore the use of these things as probative evidence against Knox/Sollecito is significantly damaged.

Having said all that, it's absolutely true to say that one must weigh the case as a whole, and that the issue of guilt must only be examined in relation to the totality of the evidence rather than on a piece-by-piece basis. However, in this case, every single item of evidence now has a very large question mark against it. It's my view that when you add together all the so-called "evidence", there is nowhere near enough to constitute guilt beyond a reasonable doubt. In fact, I'm very confident that this was the case even at the time of the Massei trial, but after events to date in the Hellmann appeal, I'm certain of it.

 

[Rolfe]

I still think the clear evidence of time of death makes it all so much simpler. Unless someone has some coherent narrative whereby Knox and Sollecito participated in a murder before about 9.30 pm.

Rolfe.

 

[LondonJohn]

Investigation desperately needs some forensic evidence tying Knox and Sollecito to the crime. Items from the cottage are problematical, because either of their DNA might have got there innocently.

So they ignore all the knives right there beside the body, and go to Sollecito's flat. There they pick one kitchen knife of several, for no readily apparent reason, ignoring others. Even though it doesn't match either the bloody impression or the wounds. This single knife is tested in multiple spots, and when the machine can't find any readable DNA, Stefanoni turns up the sensitivity to LCN levels, even though the lab has handled high-copy-number DNA of Meredith's and none of the proper procedures for testing LCN DNA were followed.

One of these samples turns up a tiny tiny amount of Meredith's DNA.

For God's sake, why do you even bother considering other ways that profile might have got there?

Rolfe.

And that's before even considering the dichotomy highlighted by Halides: if this knife was used in the murder, then either a) it was cleaned with bleach and water after the murder (as per the "stench of bleach" which apparently attracted the police to the knife in the first place), in which case there would be none of Meredith's DNA remaining on the blade, or b) it was not cleaned after the murder, in which case the knife would absolutely definitely have tested positive for Meredith's blood if it also tested positive for her DNA.

The knife had nothing whatsoever to do with the murder of Meredith Kercher. Anyone with just the most basic grasp of science has been able to see this for years now, and the Conti/Vecchiotti report does no more than put the official seal on that position. And while that fact doesn't necessarily mean that Knox and/or Sollecito had nothing to do with Meredith's murder, it does remove one huge plank that Massei's court erroneously used to tie them to the crime.

 

[Rolfe]

How do you tell that a smell of bleach is coming from a single knife in a drawer full of cutlery anyway?

This entire thing is beyond ridiculous.

Rolfe.

 

[AmyStrange]

In all the discussion over the past couple of pages, I think that Shuttlt is consistently forgetting one absolutely crucial thing: there is a massive (and correctly so) asymmetry inherent in a criminal trial which is adversarial rather than inquisitorial*. In order for Knox and/or Sollecito to be found guilty, the court must conclude that there is overwhelming evidence of their participation in the murder: in fact, the court must reason that there is no doubt (based in human reason) that Knox and/or Sollecito participated in the murder. Anything less than total proof must result in acquittals.

Therefore, all the discussion about the knife and the "confession/accusation" must be viewed in that context, if one is to discuss these issues in any meaningful way. I know that some people here are on a "search for the truth", but I still contend that a) this is probably going to be forever impossible to know for sure, and b) of only very limited relevance to the trial process of Knox and Sollecito. The only thing that is both relevant and testable is whether there is proof positive that Knox and/or Sollecito participated in the murder of Meredith Kercher. Anything less than that is effectively the null hypothesis.

Therefore my position (and the one the court should adopt) on the "confession/accusation" and the knife/bra clasp is that since there are entirely feasible ways to explain them from an innocence standpoint, they therefore carry very little weight for proving guilt. The question is not one of how conclusively one can "prove" how and when contamination occurred, nor how conclusively one can "prove" that Knox was coerced into a false confession/accusation. The fact is that both these things are very real possibilities, and therefore the use of these things as probative evidence against Knox/Sollecito is significantly damaged.

Having said all that, it's absolutely true to say that one must weigh the case as a whole, and that the issue of guilt must only be examined in relation to the totality of the evidence rather than on a piece-by-piece basis. However, in this case, every single item of evidence now has a very large question mark against it. It's my view that when you add together all the so-called "evidence", there is nowhere near enough to constitute guilt beyond a reasonable doubt. In fact, I'm very confident that this was the case even at the time of the Massei trial, but after events to date in the Hellmann appeal, I'm certain of it.

-

You and Rolfe should get a room together. You're both spoiling this for the rest of us.

Please regard my above statement as a facetious statement and in no way adjunct to the seriousness of this thread and/ or discussion as a whole,

Dave

 

[Rolfe]

And while that fact doesn't necessarily mean that Knox and/or Sollecito had nothing to do with Meredith's murder, ....

Maybe not, but the gastrointestinal tract contents do mean that, if I understand the alibi evidence correctly.

Rolfe.

 

[LondonJohn]

I still think the clear evidence of time of death makes it all so much simpler. Unless someone has some coherent narrative whereby Knox and Sollecito participated in a murder before about 9.30 pm.

Rolfe.

Absolutely. But the ToD argument (which is incredibly strong) also has to be considered alongside everything else in order to conclude that there's no case against Knox/Sollecito. For example, if all the ToD evidence were exactly as is, but the police had discovered clothing of Knox and Sollecito covered in Meredith's blood and hidden in Sollecito's apartment, then one would have to reason that Knox/Sollecito somehow found a way to be in the cottage between 9.00pm and 9.30pm.

What makes the ToD evidence so strong is the fact that it fits together perfectly with everything else we know about the evidence (or lack thereof) in this case in pointing towards Knox's/Sollecito's non-involvement. What's more, it tends to strongly support a scenario of Guede's sole participation in the killing.

(BTW, in regard to that last point, I keep reading ignorant pro-guilt commentators asserting that Knox's/Sollecito's defence teams have somehow "abandoned the lone wolf theory". Not only is this simply not true, it's also important to point out that it is not the job of Knox's/Sollecito's defence to propose an alternative view of the crime (although they may wish to do so as part of the defence). It's only the defence's job to convince the court that there is insufficient proof of Knox's/Sollecito's participation in the murder. I guess that some people can't figure this out though.)