Knox/Sollecito appeal hearing on 30th July

July 29, 2011

Barring delays, overruns or surprises, tomorrow should see the last hearing in the appeal of Amanda Knox and Raffale Sollecito before the court goes into summer recess.

On Monday, the court heard scientists Stefano Conti and Carla Vecchiotti give a rundown of their review of some of the DNA evidence in the case. They did this with the aid of a DVD containing crime scene footage, designed to illustrate flaws in police procedure in the collection and handling of evidence, but without being questioned by the prosecution or defence lawyers. This means that the likely points of contention in relation to the review have still not been gone into and, for information about that, I refer you to my previous posts here and here.

There have, however, been two developments reported in the Italian press which may stand some sort of chance of having some sort of impact on proceedings.

The Umbrialeft website is reporting that the above-mentioned DVD played to the court by Conti and Vecchiotti on Monday has since been subjected to a court order effectively stating that it forms part of the proceedings. The report is less than clear, though, as to why this event is newsworthy. My best attempt at inter-linear decoding says that what has gone on is that the prosecution have asked for a copy of the DVD and presiding judge Hellmann has then issued the order so that they might be entitled to a copy. This would just be an administrative tidying-up in relation to something that should really have been done during the court session.

However, I appreciate that this version is irritatingly probable and mundane, so here’s a different take. Francesco Maresca, lawyer for the family of Meredith Kercher, has recently been complaining to reporters that the DNA review does not appear to have been written from a disinterested standpoint. And, in last Sunday’s Observer, an unnamed police source went further, suggesting that the experts were being “fed information” by the defence.

Now, it’s all very well for lawyers and police officers to have suspicions about the integrity of the experts, but it’s not much use to the court without evidence. So, suppose that someone paying attention to DVD presentation on Monday noticed that it contained material which did not seem to have been supplied to the experts by the court. That might be prima facie evidence of undisclosed communication between the experts and the defence, or someone close to the defence. If those circumstances were to arise, the bench may well feel obliged to disregard the DNA review.

But let’s not get carried away. The simplest explanations are usually the best and, let’s face it, were the experts crooked they would surely not make such a basic error. Still, you never know…

Meanwhile, there has been a surprise twist regarding the evidence of Luciano Aviello, the gender-nonconformist Mafioso who testified a few weeks ago that the killer of Meredith Kercher was in fact his fugitive brother. At the time, this was more or less as obvious a lie as it is possible to imagine, particularly given Aviello’s record of eight separate convictions for criminal defamation and the fact that the court heard another witness claiming that Aviello had been offered a large some of money by the defence in return for his false testimony.

So, in the face of a police investigation into this claim, Aviello now says that he was offered €30,000 (which he intended to spend on a sex change operation) by the Sollecito family and with the knowledge of defence lawyers. Quite a price-tag for the worthless garbage they got in return, but maybe the Sollecitos have better money than judgement. What is more, Aviello now claims that Sollecito confided to him in prison that Knox, but not he, was responsible for the murder.

The main reason this is unlikely to have a major impact on the appeal is that, in the absence of corroborating evidence, Aviello is clearly no more reliable as a witness than he was a couple of weeks ago. The court will need to take account that his original tale, obviously and plainly false in any case, has now progressed to being plainly and obviously false. Prosecutors will need to decide whether it is worth pressing for him to testify again. Given that there exist more credible allegations as to the dirty hands of the Sollecito family, they may wish to add pressure on the bench to wonder if there might be an iceberg below. On the other hand, they may feel that the judges and juror-judges already have the information they need, and that it would be a mistake to draw attention away from the much more important matter of their rebuttal to the DNA review.

As a side-note, something that seems clear from the reporting of this story is that Aviello and Sollecito associated with each other in prison, at least according to Aviello. But, as far as I can tell, this rather material bit of information was not mentioned in court when Aviello testified on 18 June. Surely this is something that must have been known to the defence?

Regardless of whether any of these side-stories make it into the courtroom tomorrow, it promises to be the most enlightening and important session in the whole appeal. It won’t be possible to tell immediately whether it has been decisive but, for the prosecution, a lot hangs on how convincing or unconvincing their response to the DNA review turns out to be.

Advertisements

Was Casey Anthony’s DNA on the bra-clasp?

July 20, 2011
DNA readout from bra-clasp in Kercher case

Click on the image for a larger version

In 2009, the journalist Baribie Nadeau mentioned something in an article which many people will have wondered about when they read it. She said that Vincenzo Pascali, a scientific consultant for the prosecution in the early days of the process, had “hinted” that a sample taken from the bra-clasp of the murder victim Meredith Kercher had contained the DNA of not only Raffaele Sollecito but also his alleged accomplice in the crime, Amanda Knox.

It may be thought unlikely that there was much in this. That’s not to impugn Nadeau’s journalism – if a DNA expert hints at something like that then it is worth reporting. At the same time, though, you would think that, if Knox’s DNA really were present on the clasp, the prosecution would have mentioned it by now.

Nevertheless, given the information that is now available about DNA evidence in the case, I thought it would be worth looking into this suggestion.

The first thing to note – and it’s an extremely important thing to note – is that the DNA of Kercher and Sollecito found in the sample from the clasp accounts for either all or very nearly all (depending on which expert you are listening to) of the alleles observed. Since there is so little left to play with, trying to make a further DNA match out of it would seem at bit like looking at a nine and a six and wondering whose phone number in particular they might form part of. Completely impossible, even if you believe that further DNA might be present. Impossible, that is, using any method that is generally considered scientifically reliable.

What you could do, though, is lower your standards and begin to look at peaks that would ordinarily be ignored on the grounds that they could well be nothing more than noise. This makes the peaks that you are including less reliable (how much less reliable depends on how radical you are in including smaller peaks), but it might be argued that there is a legitimate trade-off. If you can get a very good match, then maybe it can be argued that a questionable peak here or there is acceptable. After all, how likely is it that the noise has simply been kind enough to appear in the exact places you would need it to in order to make you incomplete match complete?

So, you can see on the image that I’ve added green dots to the DNA profile taken from the bra-clasp, indicating the places where Knox’s alleles would be expected to be located. And it turns out that it is possible to see a fairly good degree of compatibility with the sample. But I had to go all the way and include even the tiniest bumps on the printout. Because some of these are so small that no numerical information about them is included, I also had to judge a few of the locations by eye (the blue numbers on the image indicate where I did this). This raises the additional problem that my own human error may have some effect on the reliability of what I have done.

But how strong is the actual match? Well, first you have to explain away two things. At loci D8S1179 and D19S433 (the first and tenth groups of peaks on the image), there are small peaks which the DNA review says are above the threshold where we can be confident they are noise. But they are only above the threshold by a hair’s breadth. So maybe we can consider the possibility that they really are noise. Then at locus D7S820 (the third group of peaks in the image), there’s location where you would expect to see an allele relating to Knox, but there is nothing there. Again, maybe this is not so much of a problem. We’re presumably dealing with an extremely faint DNA trace. Maybe it’s simply the case that just one peak out of 29 is so faint as to not be there at all.

What’s starting to emerge, though, is the problem with not having any real standard to go by in terms of which peaks you consider to be real and which you don’t. The judgements you have to make in order to determine whether there is compatibility or not start to become fairly subjective, at least in this case. At each locus point, the ways in which compatibility could arguably be ascertained are numerous, so things are different from how they were in considering the matches to Sollecito and Kercher. Whereas their profiles are quite clear and match 100% to unquestionably genuine alleles on the graph, it seems like you can pretty much see Knox’s DNA profile in the printout according to how much you want to.

A commenter suggested adding dots for a sample known not to be connected to the case. I thought this was a good idea, and whose DNA profile could be more suitable for the task than that of Casey Anthony, recently acquitted of murder in the US? So I’ve added her alleles using pink dots.

I think this goes to further illustrate the problem. Although there are a greater number of problematic spots on the graph that you need to ignore if you want to make Anthony’s DNA fit, some things go the other way. For example, 69% of Knox’s allele’s pair up with peaks on the graph that are above 50 RFU in height (one measure of a potentially genuine allele). It may sound from that like Knox’s DNA is beating the odds. But Anthony’s DNA profile, on the other hand, matches to those >50 RFU peaks 75% of the time. For me, it seems hard to see how you could justify being confident that Knox’s profile is there without also thinking that there is a least a decent chance that Anthony’s could also be there.

Then again, it’s always possible that I have it backwards and that, in reality, the bra-clasp printout offers a new chance for that half of America outraged by Anthony’s aquittal to get her back in court.