Amanda Knox guilty - all because of a cartwheel

[Kermit]

the signals are too weak (and have other problems) to be accepted as a good profile of Meredith’s DNA

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I have to admit that I'm not very good at detecting the counterfeit Adidas wear at the local flea market, but I'm surprised that you describe the Double DNA Knife test results as not reflecting Meredith's DNA profile.

While some of the relative heights of peaks may vary, almost marker for marker, there's an almost complete coincidence.

If I were you, this is where I would try to come up with a good contamination scenario, and put it to the test.

To convince us that that's not Meredith's DNA, but someone else's is like trying to convince us that a bunch of monkeys jumping up and down on typewriters could produce The Complete Works of William Shakespeare.

 

[Kermit]

I've only seen one of Kermit's powerpoints which was actually on the PR campain, and no offense to him (her?) (being that he is a member of this forum), but I thought it was pretty strange as about half of the power point seemed to be just listing the plots of Doug Preston's books as a rhetorical device to show that Preston, not Mignini, is obsessed with satantic rituals--where the PP maker seemed to lose site of the fact that one is proposing it as obvious fictional work.

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Hi HumanityBlues. Thanks for the constructive criticism, and I agree that listing the Preston plots (most of which have a weird element: satanical, murderous, violent, abusive or otherwise) was a rhetorical device on my part. Preston has never made any pretension of making us believe that his albino FBI agent who hangs out with an underage looking, although really 160 year old hag (she stays and looks young thanks to some sort of elixir she drank a long time ago) is anywhere near a picture which reflects reality. (Why the young/old lady is called Agent Pentupgas's "ward" beats me).

That said, neither should we assign Mignini the authorship of the "satanic" theory for the Monster of Florence crimes. Mignini is separate from the MoF investigation both in time (20 years or more, depending on when you think the MoF crimes started) and space (Mignini's jurisdiction is Perugia in Umbria, not Florence, in Tuscany).

Although FOA commenters keep posting things like Mignini has a satanic obsession, he only reactivated the old satanic theory from the MoF crimes when he had to reopen the separate 15 year old investigation into the death of Francesco Narducci, who was found apparently drowned in Lake Trasimeno near Perugia. Wiretaps of conversations of members of an organised crime gang made references to this death and led the way to connecting it (correctly or incorrectly) to the MoF case.

So, I suppose my point was that persons who try to underline Mignini's supposed obsessions with explicit comments or not-so-subtle insinuations may on one hand be much more immersed with those concepts in their own (albeit fictional) worlds than Mr. Mignini.

And, secondly, the satanic theory in the MoF case had nothing to do with Mignini, given his distance in time and space from that case.

 

[Dan O.]

Looking at the Massei Report, I can also tell you that everyone was assigned into teams before entering the cottage. Each team was assigned and restricted to one particular room, no member of which was permitted to enter any of the other rooms. This was done to further restrict any possible cross contamination.

If that's what Massei said then Massei is a liar. The videographer travelled from room to room including the boys apartment downstairs and everyone walked through the living room to get to the other rooms.

 

[Dan O.]

Thanks, so the .fsa files are just the data that the graphs we have all seen derive from?

Did you bother to look at the links to further information on that page?

• 
  Ept file
• Raw data
• Size calling curve
• Sample file information
• Analyzed data

The last one is all we saw in the presented charts but even that contains more information than what is visible in a printed chart. For instance, in the bottom half of that image you can just see another profile peaking through the noise at about 50 RFU. This profile is almost certainly due to contamination but you will have to go through the rest of the online course to learn about causes of contamination.

 

[Fulcanelli]

If that's what Massei said then Massei is a liar. The videographer travelled from room to room including the boys apartment downstairs and everyone walked through the living room to get to the other rooms.

This applies to the upstairs flat of the cottage and obviously only to the 'enclosed' rooms...such as the bedrooms and bathrooms.

 

[Kermit]

Chris/Halides1 said about Meredith's DNA on the knife:
"the signals are too weak (and have other problems) to be accepted as a good profile of Meredith’s DNA"

... but Dan-O just said:
"you will have to go through the rest of the online course to learn about causes of contamination."

Unfortunately, I don't have time for the online course, but I'll assume you've done it, so I ask you: do you think that the DNA profile on the knife matches Meredith's DNA? (or, on the contrary, is the profile too unreliable to be said that it matches her?)

Here's the next point in the decision tree: if the profile can be ascribed to Meredith, do you think it was due to contamination? Which of the online course's causes of contamination do you think caused this contamination? Or are you only able to say in generic terms that "contamination can happen"?

Dr. Patrizia Stefanoni has stated that there has never been a case of contamination of DNA samples in the history of her lab. To the supporters of the contaminated Double DNA Knife Theory, was it just bad luck (for Amanda) that it occurred this time?

(in the decision tree, if you believe that the profile is too unreliable to be ascribed to Meredith, then of course, save your breath about the contamination ... in that case, I assume you might say that Stefanoni mistook the unreliable DNA sample of an apple seed or something like that which the knife cut, with Meredith's control DNA sample ... but what a coincidence that each peak in the apple seed profile matches a peak in Meredith's profile. Amazing.)

 

[shuttlt]

Did you bother to look at the links to further information on that page?

• 
  Ept file
• Raw data
• Size calling curve
• Sample file information
• Analyzed data

Yes, I did look. You are right though, what I said wasn't quite correct. The fasta file format contains the analysed data (which is more or less equivalent to the graphs we've all seen), plus the raw data that the graph data derives from, plus a bunch of other stuff.

 

[BobTheDonkey]

BobTheDonkey,

You misunderstand the two arguments against taking the knife profile as good evidence. The first is that the signals are too weak (and have other problems) to be accepted as a good profile of Meredith’s DNA. Before we get to the second argument, let’s be clear about one thing. The knife was tested for blood using tetramethylbenzidine, which is a very sensitive assay. There was no blood on the knife. Period.

The second argument starts with this lack of blood. If a bloody knife were cleaned to the point of not having detectable blood, it is somewhere between unlikely and impossible that there would be DNA left on the blade. Therefore, any DNA that one observed probably came from contamination. This argument is equally valid for a strong or a weak profile, IMHO.

The two arguments do not contradict each other; I accept both of them. Either one is enough to make one dubious of the claim that the knife DNA profile is solid evidence.

Chris

Round and round we go, will it never end?

What are the odds that someone else's DNA profile would show up matching Meredith's on a piece of evidence connected to her own murder? Again, not an argument from incredulity. You claim to be a DNA expert, so let's hear just how many people involved could have had DNA so similar to Meredith's.

 

[shuttlt]

To be fair to Chris, without the raw data it is probably a bit tricky to give a definite answer to that question. Right now nobody here has access to enough information to do more than say: "if the information that I don't have looks like this, then....".

 

[Kermit]

... let’s be clear about one thing. The knife was tested for blood using tetramethylbenzidine, which is a very sensitive assay. There was no blood on the knife. Period.
.... Chris

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Hi Chris. I certainly don't have the DNA qualifications that you do, and in fact, all I know about this topic is what I google up.

Words which are hard to pronounce are the best ones to google, so I just typed in: tetramethylbenzidine dna (enter)

The first response I got is:
http://static.dna.gov/lab-manual/ PDF file

It's interesting, because it describes the six steps for a tetramethylbenzidine ( did I say that right? ) blood test:

"PROCEDURE OR ANALYSIS

1. Swab suspected blood stain with clean filter paper or a swab, which may
be moistened if necessary with deionized water, ethanol or saline.

2. Apply 1-2 drops of the TMB reagent.

3. Note any blue-green color change. A blue-green color change at this step
indicates a chemical oxidant and the test should be considered inconclusive.
If there is no color change, proceed to the next step.

4. Add 1-2 drops of 3% hydrogen peroxide.

5. Note any immediate blue-green color change

6. An immediate blue-green color change indicates a positive result. No
color change indicates a negative result. A negative result indicates that
either no blood is present or is below the limit of detection of the test."


What intrigues me is that last line. It seems to indicate that for as sensitive as tetramethylbensidine may be, this US Department of Justice government agency does recognise that blood can be present which goes undetected.

But if that's the case, why would that group of scientists who were requested to do their critique of the Double DNA Knife results by FOA or people close to FOA say that if the TMB doesn't catch it, it ain't there?

 

[shuttlt]

2-4 drops is quite a lot, given that there may well be a few hundred (or even fewer) red blood cells to detect. I've been assuming that the 1:10,000 sensitivity is the proportion of red blood cells to liquid we're desolving it in.

 

[Kermit]

2-4 drops is quite a lot, given that there may well be a few hundred (or even fewer) red blood cells to detect. I've been assuming that the 1:10,000 sensitivity is the proportion of red blood cells to liquid we're desolving it in.

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Step 1 of the Department of Justice instructions refer to the "stain" you're testing, so presumably if you're testing cells and not a stain measured in square centimeters, you would reduce the quantities, perhaps even change the procedures (e.g. use a microscope).

In any case, maybe the question of proportions is the explanation of why the TMB didn't apparently react for blood, a lack of reaction that the Department of Justice recognises can happen.

 

[shuttlt]

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Step 1 of the Department of Justice instructions refer to the "stain" you're testing, so presumably if you're testing cells and not a stain measured in square centimeters, you would reduce the quantities, perhaps even change the procedures (e.g. use a microscope).

In any case, maybe the question of proportions is the explanation of why the TMB didn't apparently react for blood, a lack of reaction that the Department of Justice recognises can happen.

True, but this is one of the recurring problems with discussing the blood and LCN tests to make a unified point. One's precision is given in terms of cells and one is given in terms of dilution (not to mention the different sized samples and that they are each detecting different things in the samples that exist in an unknown ratio). Comparing them is very hard. As for "stains", there was a "stain" in the scratch on the knife, or so we're told.

 

[Fulcanelli]

Hi Chris. I certainly don't have the DNA qualifications that you do, and in fact, all I know about this topic is what I google up.

He doesn't have any qualifications regarding DNA or forensics. He's a chemist.

 

[Kermit]

True, but this is one of the recurring problems with discussing the blood and LCN tests to make a unified point. One's precision is given in terms of cells and one is given in terms of dilution (not to mention the different sized samples and that they are each detecting different things in the samples that exist in an unknown ratio). Comparing them is very hard ....

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You're right. My main point was simply to counter the statement that if the TMB doesn't react, there can be no blood.

In that sense, I think we're advancing, because that statement now seems to be not the case.
===================

So, if we have a low number of cells (eg. hundreds, maybe only dozens), the question is: can such a low number of cells be tested with a certain level of reliability for DNA (even if the TMB blood test didn't give conclusive results)?

My understanding is: a definitive yes.

 

[Fulcanelli]

Regarding LCN DNA testing, download the attached PDF article in this post here on PMF:

http://www.perugiamurderfile.org/viewtopic.php?p=38453#p38453

And I'll quote here the following post from PMF made in response to the above linked article:

Interesting. The article states that only two labs in the US require blind testing for their controls in regard to testing LCN DNA. In other words, blind control tests are not the norm. This has been a recent favourite complaint by certain sections of the FOA who have claimed (without supporting it with evidence I would add) that blind controls were not used in testing the knife and have complained about this as though it is both a US national and international standard, when no such standard exist.

It also makes it clear that "None of the labs disclose what they do, they say it is proprietary information." This is in complete contrast to the FOA's claim that the Rome lab is somehow breaking some internationally recognised standard by not releasing data such as the control set or the .fsa files. Again we see that for all their talk it's just smoke and mirrors dressed up to appear as though the Rome lab is committing some terrible foul that isn't done elsewhere, where in fact it is the NORM.

http://www.perugiamurderfile.org/viewtopic.php?p=38454#p38454

 

[Chris_Halkides]

sensitivity of TMB

J. L. Webb, J. I. Creamer and T. I. Quickenden
Luminescence 2006; 21: 214–220.

This paper gives the maximum detectable dilutions for a commercial preparation of TMB as 1:100,000 for a dried 50-microliter bloodstain and 1:1,000,000 for a solution. The dilutions refer to a hemoglobin concentration of 150 g/L, which is the physiological concentration. In other words, the 10,000 fold dilution figure in the Johnson/Hampikian letter is a conservative estimate. They used the words “at least 1:10,000.” The bottom line is that TMB is a very sensitive test.

All tests have a sensitivity limit. The question is what are the relative sensitivity limits for hemoglobin and for DNA in blood, bearing in mind that blood has lots of hemoglobin but is not rich in DNA. The Johnson/Hampikian letter stated, “This DNA does not originate from blood. A highly sensitive chemical test for blood was negative, and it is unlikely that all chemically detectable traces of blood could be removed while retaining sufficient cells to produce a DNA profile consistent with the victim.” Dr. Johnson was even more emphatic when interviewed by ABC, where she stated, “if someone had a knife covered in blood and they tried to clean it very well, they would remove their ability to detect the DNA before they removed the ability to detect the chemical traces of blood.”

 

[BobTheDonkey]

J. L. Webb, J. I. Creamer and T. I. Quickenden
Luminescence 2006; 21: 214–220.

This paper gives the maximum detectable dilutions for a commercial preparation of TMB as 1:100,000 for a dried 50-microliter bloodstain and 1:1,000,000 for a solution. The dilutions refer to a hemoglobin concentration of 150 g/L, which is the physiological concentration. In other words, the 10,000 fold dilution figure in the Johnson/Hampikian letter is a conservative estimate. They used the words “at least 1:10,000.” The bottom line is that TMB is a very sensitive test.

All tests have a sensitivity limit. The question is what are the relative sensitivity limits for hemoglobin and for DNA in blood, bearing in mind that blood has lots of hemoglobin but is not rich in DNA. The Johnson/Hampikian letter stated, “This DNA does not originate from blood. A highly sensitive chemical test for blood was negative, and it is unlikely that all chemically detectable traces of blood could be removed while retaining sufficient cells to produce a DNA profile consistent with the victim.” Dr. Johnson was even more emphatic when interviewed by ABC, where she stated, “if someone had a knife covered in blood and they tried to clean it very well, they would remove their ability to detect the DNA before they removed the ability to detect the chemical traces of blood.”

Are blood cells the only cells that contain DNA?

As quoted above, the test is not absolute. The results can either be inconclusive, positive, or negative or (and this, kids, is an important distinction) too small for detection.

Note that "negative" is not a result on it's own. It's Negative OR Too small for detection. That means that the result cannot be simply negative, especially not in this case where we're talking about so few cells.

Dr Johnson's failure to acknowledge this important result correctly tells me that her opinion on the DNA involved in this case isn't worth a plugged nickel

 

[tsig]

If that's what Massei said then Massei is a liar. The videographer travelled from room to room including the boys apartment downstairs and everyone walked through the living room to get to the other rooms.

Another liar! Will the list never end? Obviously they should lock up everyone but Amanda.

 

[Kermit]

Dr Johnson's failure to acknowledge this important result correctly tells me that her opinion on the DNA involved in this case isn't worth a plugged nickel

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Part of the explanation of why Elizabeth Johnson sculpted her report the way she did could lay in the answer to how and why she was engaged to do this report, who engaged her, who gave her the material which she based her report on.

Maybe someone from FOA could give us some answers to those questions.