Friends of Amanda Knox video: Mark Waterbury

Mark Waterbury

Mark Waterbury is an engineer and businessman from King County, just outside Seattle. He’s a key member of Friends of Amanda Knox, and has self-published a book on the Meredith Kercher case entitled The Monster of Perugia: The Framing of Amanda Knox.

Like Steve Moore, he begins his presentation at the Case for Innocence event with a somewhat unsatisfactory allegory involving animals. Amanda Knox and Raffaele Sollecito are two canaries choking in a mineshaft of DNA evidence. This image seems to turn logic on its head. Instead of using the evidence to determine guilt or innocence, the proposition seems to be that, if the evidence seems to incriminate the canaries, this should only serve to alert us that there is a problem with evidence. Knox and Sollecito stand at the “cutting edge”, Waterbury says, in exposing the failure of modern forensics.

Waterbury thinks that DNA evidence is all well and good, but that it is open to abuse. The reasons for distrusting what has been presented in the Kercher case are, for him, common sense. A detailed understanding of the science is not needed. For me, that was disappointing to hear, because I think that, if there are any problems with the DNA evidence in the case, then the technical detail is where we need to look, whether it is easy to understand or not.

Waterbury looks in particular at evidence regarding the knife alleged by prosecutors to have been used by Knox to stab Kercher. Knox’s DNA was found on the handle and a tiny amount of Kercher’s was found in a notch on the blade. Knox’s DNA, he suggests, can be explained because it was her boyfriend’s and she had used it for cooking. Maybe that’s possible.

Regarding the victim’s DNA, he points out that the knife underwent a presumptive test for blood, using the chemical TMB, which was negative. For Waterbury, this makes nonsense of the DNA finding. But, even assuming the negative test definitively means that the material was not blood (given the tiny size of the sample, I am not sure whether or not this is correct), I can’t see why it doesn’t still make perfect sense. The knife, it is said, was used to stab someone in the neck. The prosecution claim that it was thoroughly cleaned afterwards. It may well be that this removed all trace of blood. But a tiny piece of skin, muscle or arterial tissue, invisible to the naked eye and caught in a notch could surely have been left on the blade.

Next, Waterbury turns his attention to the fact that the the DNA results were amplified. He tells a story (which, to be honest, I found quite difficult to follow) about a device designed to detect “a very unusual material” which, on one occasion detected a toilet instead. But I’m not sure what the moral of the tale is. Somehow, it seems that he is linking this to the idea that contamination may have been an issue with the DNA testing.

The lab tested various samples which contained Kercher’s DNA. The crux of what Waterbury says is that, because the sample from the knife was so small that it required amplification, traces left by earlier tests could have been left on the equipment and revealed themselves during the amplification, effectively giving a false positive. But standard procedures should prevent this. According to Patrizia Stefanoni, who oversaw the testing, these were part of her procedure and the risk of such contamination was zero. So, Waterbury has identified a theoretical risk, but Stefanofi denies that it is a real risk. I would be very interested to see an expert assessment of Stefanofi’s work. Was there some as yet uncovered flaw in her procedure?

Waterbury says that the prosecution refuses to release the results of her “negative control tests” (i.e. tests between tests to check if any stray DNA is present). I don’t think he is correct on this point. During the original trial, Judge Massei compelled the prosecution to release all of Stefanofi’s notes and they did so, albeit reluctantly. In any event, what does Waterbury imagine that the notes show? Did she write: “I found the equipment to be contaminated with the victim’s DNA but I went ahead with the test anyway”? That seems unlikely.

Whilst it may be possible in principle, as Waterbury suggests, that Knox’s DNA got onto the handle of the knife prior to the murder (how likely that is is a question for the court), I don’t think he says anything that provides a real challenge to the finding that Kercher’s was on the blade. And, since the knife was found at Sollecito’s flat, it remains incriminating for our two canaries. I can’t see how this problem can be evaded.

I think Waterbury has chosen well in terms of what he is focussing on. If there is something wrong with Stafanoni’s negative control tests then that would significantly aid the defence. But I can’t see any good reason to suppose there was, unless you subscribe to Waterbury’s “mineshaft” thesis (i.e. you know from the outset that there must be an error somewhere, it’s just a question of identifying it).

The competence or otherwise of Stefanoni’s work is currently being assessed in Rome as part of the current appeal. If there are any legitimate grounds to doubt that she found Kercher’s DNA on the blade of the knife, those should soon be resolved one way or the other.

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20 Responses to Friends of Amanda Knox video: Mark Waterbury

  1. Terence says:

    You have a very ‘readable’ way of writing, which is a breathe of fresh air amongst all the badly written information on the web. You position important details in a simple fashion, excluding the tons of gumf that is out there. Keep it up!

  2. BillyBob says:

    The knife was not cleaned. It had recently been used for cooking and there is starch residue from pasta water on the blade. This information was leaked several weeks ago.

    Knife not cleaned = knife not murder weapon. Meredith’s DNA was never on the knife in the first place. Stefanoni did not use standard procedure for testing the knife. She invented a new one.

  3. BillyBob says:

    The knife wasn’t thoroughly washed. That’s what the starch means. The last use of the knife was for cooking. The knife did not spend part of the evening of Nov 1st embedded in someone’s throat drenched in blood.

    • maundy says:

      Did you read that post, BillyBob? The story about starch comes from Frank Sfarzo. According to him, the quantity of starch found was 5 picograms. That’s unimaginably tiny. An amoeba would need a magnifying glass to see it. Assuming Frank’s story is accurate, it doesn’t tell us anything about whether or how the knife was cleaned.

  4. Harry Rag says:

    Dr. Renato Biondo, Professor Francesca Torricelli, Luciano Garofano and Professor Giuseppe Novelli have already reviewed the DNA tests and confirmed Dr. Stefanoni’s findings. This is ominous for Knox and Sollecito.

  5. BillyBob says:

    It’s impossible to confirm Dr Stefanoni’s findings because there is no DNA on the knife.

    • Harry Rag says:

      Dr. Stefanoni said there was only enough DNA on the blade of the knife for one test. Stefano Conti and Carla Vecchiotti will now have to examine the procedures used by Dr. Stefanoni and her team and rely on the original results as a baseline.

  6. BillyBob says:

    In that case Dr Stefanoni departed from any recognzied procedure. LCN DNA testing requires two tests.

    Stefanoni’s testing was invalid, and the starch from cooking on the knife shows it was not the murder weapon.

    • maundy says:

      The fact that the test was unrepeatable is a limitation which the court will have to take into account. I don’t think there’s any basis for suggestion this is a departure from recognised procedure or invalid. I think the results would have been easy for the defence to knock out if that had been the case.

  7. BillyBob says:

    The defence requested independent testing of the knife at the first trial but this was refused.

  8. maundy,
    When one works at low template numbers of DNA, the consensus appears to be that one must test it at least twice, and then one takes only those alleles that show up in both runs. This is one of the defining aspects to low copy number (LCN) DNA profiling. Stefanoni’s test fails in other respects as well, such as the need for an ultraclean lab.

    However, the most serious problem for me is the lack of blood on the knife. One has to believe in magic cleaning fluid that removes blood but not DNA to explain the result.

    • maundy says:

      Hi Chris. I think the best people to comment on all that are the people doing the current review.

      As far as I know, repeating DNA tests is always recommended, but that doesn’t say anything about whether you should disregard results where retesting is not possible. This is more a question of legal evidence than of science (ie the question of whether the evidence should be admissible is informed by scientists, but decided by lawyers).

      I don’t think much is known about how well set up Stefanoni’s lab was. It’s an interesting question, but I don’t think you have the information to be able to say “it fails”. We just don’t know. But, again, the review will probably comment on this if it is an issue.

      Magic cleaning fluid? The knife seems to have been almost entirely clean, with perhaps only two tiny samples of material on it. That does suggest pretty thorough cleaning, but I think “magic” is overstating it.

  9. Maundy Gregory,
    The prosecution failed to release the electronic data files or other files that pertain to the DNA evidence. I have several articles on my blog that cover this important point. Release of the electronic data files is a near-universal norm, according to Dr. Dan Krane, an expert in DNA forensics.

    • maundy says:

      I’ve no idea whether its a norm or not, and I am not sure who sets the norms. I agree, though, that there should be no good reason not to release these.

      The thing is that there is no evidence that I know of that these haven’t been released. Greg Hampikian complains that they haven’t been released to him. But he works for the Knox family, not for the defence, and he is not a lawyer. Lawyers working for the defence are the only people normally entitled to disclosure from the prosecution.

  10. vince says:

    I for one am not convinced that this knife is the murder weapon but what is most damning about it is rafaelle’s reaction on hearing about it. Instead of screaming to the rooftops that that it would be impossible for the Police to have found such a murder weapon (as knox did on hearing about the finding from her parents)he instead claimed that the dna got there when he pricked meredith’s hand whilst cooking at his apartment. why did he feel the need to make an excuse up for this knife????

  11. maundy,

    Somewhat surprisingly, negative control tests are sometimes faked, a subject discussed in the article, “Tarnish on the Gold Standard,” by WIlliam C. Thompson. In one case, a careful examination of the negative control runs showed that the same anomaly showed up over and over again, indicating that the technician was simply faking multiple runs and substituting a single electropherogram. One reason a technician might falsify a negative control has nothing to do with that technician’s impression of the case; rather, when DNA shows up in the negative control, all the runs have to be repeated. This might throw off a tight work schedule. If the electronic data files are eventually released, I would look for evidence of falsification of the negative controls, among other things.

    What Stefanoni actually released were a few unnumbered pages of notes, not everything that she had. It is a shame that the Judge did not compel here to release more.

  12. DNA cannot be dated; therefore, Amanda’s DNA on the handle could have come from any time she chopped potatoes or whatnot at Raffaele’s flat. I happen to believe that the Meredith’s profile on the knife falls short of what a proper DNA profile ought to be from a legal standpoint, but I do not dispute that Meredith’s DNA gave rise to the peaks we observe on the electropherogram. That’s not the issue; the issue is when and how her DNA came to be there. Two factors suggest contamination or possibly secondary transfer. The first is that low template DNA analysis is more likely to pick up random contaminants (hence the need for greater stringency in technique) than even regular DNA profiling (for which contamination is a documented phenomenon). The second is that the lack of blood makes it unlikely that Meredith’s DNA could remain on the blade while her blood could be completely removed.

    Think about it this way. The prosecution would have us believe that AK and RS would use two knives but not dispose of one of them and that they would clean the blade so thoroughly that no blood remained yet not clean the handle (which would remove AK’s DNA). That makes little sense.

  13. I am not sure what you mean by drawing a distinction between working for the defense and working for the Knox family, nor do I know that your description of this is accurate. With respect to the release of files Dan Krane wrote, “The biggest concern that I personally have regarding this case is the refusal of the prosecution to provide the defense with a copy of the electronic data that underlies the DNA test results — that is virtually unheard of world-wide today and it would be especially important to review that data in a case such as this which seems to involve such low level samples.”

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