7. The Meredith Kercher Case - Doing the Math

Earlier this year, authors Leila Schneps and Coralie Colmez published their book Math on Trial.

In it, they discuss a number of cases where, they allege, mathematical errors were made in court. One of the cases discussed is the case against Amanda Knox and Raffaele Sollecito.

The authors explain that, in this case, the Appeal Court's decision to not re-test the DNA evidence found on the so-called double-DNA knife was flawed. In an article in the New York Times, they summed up their position as follows:

"One of the major pieces of evidence was a knife collected from Mr. Sollecito’s apartment, which according to a forensic scientist contained a tiny trace of DNA from the victim. Even though the identification of the DNA sample with Ms. Kercher seemed clear, there was too little genetic material to obtain a fully reliable result — at least back in 2007.

By the time Ms. Knox’s appeal was decided in 2011, however, techniques had advanced sufficiently to make a retest of the knife possible, and the prosecution asked the judge to have one done. But he refused. His reasoning? If the scientific community recognizes that a test on so small a sample cannot establish identity beyond a reasonable doubt, he explained, then neither could a second test on an even smaller sample.

Whatever concerns the judge might have had regarding the reliability of DNA tests, he demonstrated a clear mathematical fallacy: assuming that repeating the test could tell us nothing about the reliability of the original results. In fact, doing a test twice and obtaining the same result would tell us something about the likely accuracy of the first result. Getting the same result after a third test would give yet more credence to the original finding."

Is this criticism fair? Did the Appeal Court flunk its math exam?

Well, to my mind the answer to this is yes and no. The Appeal Court ultimately did err in its assessment of probabilities, but, ironically, it did not err in the way the Schneps and Colmez seem to think.

Why is this? Well, for a very simply reason: the authors misrepresent the Appeal Court's reasoning. After all, when it comes to the question of whether a new test should be preformed, this is what the Appeal Court actually said:

"In fact, (the prosecution) argued that systems currently exist able to analyse such low quantities, albeit still at a developmental stage. This Court holds, however, that it is precisely the fact they are still under development, in practice in an experimental phase, which precludes us from basing a belief in guilt on the results obtained with the application of such systems: the Judge can do no else but base his or her opinions on the technical systems and established scientific knowledge from a particular time period – the period in which s/he is called to judge – and not on others still in an experimental phase. This, once again, to reach a decision of guilty beyond any reasonable doubt."

So what does this mean? Well, the Appeal Court is definitely not saying "the first test yielded an inconclusive result; the second test would yield another inclusive result, so let's not do the new test". What the court is saying, is that any new test (regardless of the outcome) would be irrelevant, simply because such a new test would have to be carried out by "systems" that are "still in development" and "experimental" and, therefore, inherently untrustworthy.

Schneps and Colmez seem to think that this a case where you could have had two single results, both of which might be quite acceptable, but both of which, when considered singularly, are inconclusive. They seem to think that the Appeal Court made the basic error of not considering that two such results might well prove to be much more relevant when taken together. However, that is clearly not what the Appeal Court has done.

So much, then, for Schneps's and Colmez's argument. They have simply misrepresented the Appeal Court's reasoning and, based on that misrepresentation, erroneously assumed the court made some sort of mathematical error.

The question remains, though - did the Appeal Court do its math properly? I would say not.

Why?

Well, Schneps and Colmez are right in one thing. The Appeal Court does seem to have muddled its understanding of the law of probabilities. However, what's in question is not the probability of just one or two DNA tests leading to a reliable result with regard to the knife; instead, it's the probability of the entire case. That is: of all the bits and pieces that, when fitted together, drew the original court to its conclusion that that Knox and Sollecito must be guilty.

What the Appeal Court has done is that it looks at all these bits and pieces separately. It then rejects them all. Not because they could not possibly lead to the conclusion that Knox and Sollecito are guilty, but rather because, seen singularly, they do not lead to that inevitable conclusion. And, the Appeal Court then reasons that, since there is not one single bit of evidence that would, in itself, prove their guilt beyond a reasonable doubt, all the various bits and pieces taken together wouldn't either.

Now this is a clear error, and it can be simply demonstrated.

Let's look at this from a simple mathematical point of view and assume that there are various aspects of the case which could point to guilt and which might not, and let's assume that each aspect has a 50% to 50% ratio between the two.

For example: the break-in. There's a 50% chance it was real; there's a 50% chance it was staged. Kercher's DNA on the knife? A 50% chance it was there; a 50% chance it wasn't.

Now let's sum up a number of the most important factors, two of which I've just mentioned. Here's a somewhat simplified list:


                                                Guilty                                      Innocent
Break-in                                    50%                                          50%
DNA knife                                 50%                                          50%
DNA bra clasp                          50%                                          50%
Luminol traces                          50%                                          50%
Footprint on mat                       50%                                          50%
DNA traces bathroom               50%                                          50%

Total                                          50%                                          50%

From this simple list, anyone would assume that there's a 50% chance that Knox and Sollecito are guilty, and a 50% chance that they are innocent. So that would clearly implicate that they should be cleared in court; the Appeal Court correctly acquitted them, right?

Well, not so. The thing is, of all these various factors, there is really only one that must be taken into consideration when assuming guilt. That's the break-in. As I've stated earlier, there is no way in which Knox and Sollecito might be guilty if the break-in actually occurred. To put it another way, if the apartment was actually broken into, one must assume their innocence.

Such an assumption need not in any way be made when it comes to any of the other factors, however. The assumption that Kercher's DNA was on not the knife, for example, does not in any way lead to conclusion that Knox and Sollecito must be innocent. The same applies to the DNA found on the bra clasp; the same applies to the Luminol traces, etc.

Conversely, if any of these factors did indeed conclusively point to Knox's or Sollecito's involvement, any single factor would be sufficient to establish their guilt. If, for example, it must be assumed that Sollecito's footprint was found on the mat in the small bathroom, it must be assumed that Knox and Sollecito are indeed guilty.

So let's do the math. Are Knox and Sollecito guilty? Well, there's a 50% startling chance. Does that get any lower? No; none of the factors mentioned in my list can decrease that. Can it get any higher? Certainly: if the chances of their innocence decrease, the chances of their guilt rise proportionally.

Are they innocent? Well, again you start with a 50% chance. Does that get any lower? Oh, yes. You start out with the break-in, which is where your initial 50% comes from. But next you'd have to assume that Kercher's DNA is not on the knife. So that's another 50%. You're left with 50% x 50% = 25%. Then you move to the bra clasp. Another 50%. That makes 12,5%. You move on through the remaining factors, and end up with a rather stunning 0,78% chance of them being innocent. Yes, that's right: less than 1%. Conversely, there's a higher than 99% chance that they're guilty.

Now, don't get me wrong. I'm not seriously suggesting that you could settle the whole case by simply doing a few sums. What I am suggesting, though, is that there is a basic error in the Appeal Court's reasoning.  

The error is very simple. You can't look at this case and say that there's not a single piece of evidence that necessarily leads to Knox's and Sollecito's guilt, and then leave it at that. You have to look at all the pieces of evidence, and you have to look at all those pieces together. If you do, the picture becomes quite different, and it simply becomes rather difficult to assume their innocence. 

Can that assumption still be made? Yes, I would say it can. Just not in the way in which the Appeal Court has attempted it. Its logic isn't very sound, and neither is its math.
   

6. The Meredith Kercher Case - Back to the Drawing Board (Part Six)

Meredith Kercher

Introduction

In the earlier parts of this series, I talked about the Appeal Court's verdict and discussed some aspects which may have fallen foul of the Court of Cassation's judgement.

But I've not yet really given a summary of what the current situation is, or what to make of it.

I'll do so here.

What do we know?

Well, we know the Court of Cassation has quashed the Appeal Court's acquittals. We know that it didn't do so just because there may have been a few mild irregularities in that verdict; the Appeal Court must, in the Court of Cassation's mind, have erred to such an extent as to make its decision - the acquittals - suspect.

As such, we know that the Appeal Court's verdict cannot stand and that at least certain crucial aspects of the case will have to be retried.

But we do not know what those aspects will be, and we do not know what the outcome of the new appeal will be, either.

All this will become a little clearer once the Court of Cassation reveals its substantiation. We will know if, for example, if the Court of Cassation felt that the Appeal Court's ruling was wrong on so many counts that, effectively, the entire appeal will have to handled all over again. Or we know that, conversely, the Court of Cassation has limited its objections to the Appeal Court's ruling to certain specific issues, and will direct a new appeal court to examine those issues only.

What do I think?

In the earlier parts of this series, I looked at various parts of the Appeal Court's decision in some detail. But now, having done so, I think that it's perhaps wise to first examine the general approach the Appeal Court has taken in this manner.

If you remember, the original court's take on the case seems to me to be, all told, logical. That court looked at the evidence, weighed it, and then proceeded to give a detailed picture of what must have occurred. One might well disagree with the outcome, or indeed with the details of the reasoning involved, but the approach as such makes sense.

The Appeal Court, however, handles the matter quite differently. It doesn't set out to try and explain what happened; it simply sets out to examine each singular part of the original court's verdict and then to dismiss it. At times, it is fairly successful in doing so, and at others, not so much. All the while though, it refuses to look at the overall picture.

To my mind, this is ultimately one of the major failings of the appeal ruling.

Consider these simple facts. The murder may have been committed by Guede, Knox and Sollecito together. Or it may have been committed by Guede alone. Given the facts in this particular case, those are the only realistic two options. In one way or another, any court will have to decide between these two.

The original court, as stated, makes a clear choice: all three committed the murder. The Appeal Court, however, does not. It clears Knox and Sollecito, but in doing so, it leaves quite a few questions outstanding which would need to be answered if one were to assume Guede were the sole perpetrator. 

Take, for example, the break-in. It need not have been staged, the Appeal Court asserts; but it then stops short of stating that all the evidence provided must have pointed to an actual break-in committed by Guede.

This seems a singularly strange and unconvincing way to determine the outcome of the case (*). Okay, let's say the break-in needn't be staged by Knox and Sollecito; let's assume it might have been Guede acting on his own. But what then? As I pointed out in Part One of this series, this notion would imply that Guede broke in just before Kercher herself returned to the apartment - but what on earth happened then? How it it possible that Guede, the opportunistic burglar, so suddenly turned into the sexually aggressive murderer?  How did he, and indeed Kercher as well, act? How did Guede manage to kill her? How did he manage to leave just a single bloody footprint on the bathroom mat and then a trail of bloody shoeprints exiting the apartment? How did he do all this and leave the apartment in such a state that, the very next morning, Knox arrived and didn't realise anything of real importance was amiss? 

The Appeal Court, in its reasoning, addresses none of these issues. It simply refuses to look much further beyond its conclusion that the evidence against Knox and Sollecito is insufficient. And, indeed, the Appeal Court, in one instance at least, also seems to simply ignore the facts presented to it. After all, in the original trial, the court looked at some length at the state of Kercher's body and the many wounds inflicted upon her, only to conclude that it must be assumed that more than one person attacked Kercher. This would seem to be a crucial observation, but it is one that the Appeal Court has decided not to dwell on at all.

So, in general, it seems the Appeal Court has only done half the work it should have done in reaching its acquittals. It clears Knox and Sollecito, but in doing so, its half-hearted acceptance that Guede must  must have committed the murder on his own remains insufficiently substantiated. And in this particular case - where there really are only these two options - that just doesn't seem to suffice. It seems to be the wrong approach; and it seems, more particularly, singularly inconclusive.

Because of this, I would think it very possible that the Court of Cassation would have decided that the entire Appeal Court ruling is, essentially, flawed. And that would lead to the conclusion that it must have quashed the ruling almost in its entirety. There might well still be certain aspects of the appeal ruling which escape this sanction - the witness testimonies spring to mind - but by and large, we're talking about an annulment across the board.

If this were to be the case, the appeal court that will handle the appeal (that is, the appeal court in Florence) will presumably have a fairly open schedule to work with. It will have to reach clearer and more decisive conclusions if it were to determine that Guede was the sole perpetrator, but would, in essence, be free to decide what those conclusions could be.

What if, alternatively, the Court of Cassation focused on various specific aspects of the case and dealt with them piecemeal, as I have done in the earlier parts of this series? Well, in that case, I think it would be logical to focus on a number of major issues, and I would suspect those issues to be the following:

• the break-in, as mentioned above (and as discussed in Part One of this series);
• the DNA evidence with regard to the double-DNA knife and, in particular, the question if the experts appointed by the Appeal Court have by acceptable means truly established that the results from the DNA testing should be disregarded (see Part Two of the series);
• the question of whether the mixed DNA traces discovered by the use of Luminol should be attributed to any activity involved with the crime or whether the causes of these traces are innocuous (see Part Four of the series).

If the Court of Cassation has taken this piecemeal approach, it will undoubtedly hand down various more or less detailed instructions to the appeal court in Florence for dealing with each matter. For example, when it comes to the double-DNA knife, it could instruct the appeal court to conduct a new DNA test, or to specifically determine whether or not the result arrived at can, in this case, be considered reliable, regardless of any general rules or recommendations by the "scientific community".

My own feeling is that the Court of Cassation will have chosen the first, and rather more holistic, option. It seems the fairest - and, indeed, the easiest - course of action. It also allows the Court of Cassation to stick to its own rules: don't deal with the facts, just deal with the law. If, as might well be possible, the Court of Cassation feels that the Appeal Court's decision as a whole is "manifestly illogical" (**), it will have struck down that decision more or less in its entirety.  

Back to the Drawing Board

In my original series, The Trial in Perugia, I attempted to give an overview of the case and the way the original court had looked at it. 

Back then, I gave the following synopsis of the original court's ruling:

A. Rudy Guede is guilty of the murder;
B. Guede did not act alone;
C. the only possible accomplices of Guede are Amanda Knox and Raffaele Sollecito;
D. that Knox and Sollecito are culpable of the murder is corroborated by the forensic evidence available;
E. and it is also corroborated by the fact that their stories don’t seem to be logical and do not constitute convincing alibis.
 
So, has anything really changed since then? Actually, no. The Appeal Court has, most assuredly, knocked some possible holes in the original court's reasoning, but it hasn't really changed the overall picture. That picture remains the same.

So what are we left with? After two complex court cases, I think it might well be, simply put, the break-in.

After all, when you think about this case what is the one, single most extraordinary aspect? Is it the DNA evidence, all the commotion surrounding the double-DNA knife? No, not really. Is it Sollecito's possible footprint on the bathroom mat? Again, no. Is it the wounds on Kercher's body, which seem to indicate more than one assailant? Again, no.

The single most extraordinary aspect of this case is, to my mind, the question of whether the break-in was staged or not. This is far and away the most intriguing and beguiling part of the entire story, and the way one looks at it determines the outcome of the entire case. If, as I stated earlier, one believes that the break-in actually occured, it is very hard to imagine that Knox and Sollecito are, indeed, guilty. If, alternatively, one believes that the break-in was staged, it becomes almost impossible to believe they are innnocent.

So, I end where I began, a few years ago; I end with the break-in. Personally, I find it very difficult to see how it might have really happened; I find it difficult to see how it could have been anything else but staged. Nothing the Appeal Court has said has dissuaded me from this point of view; to be frank, the Appeal Court has offered no real new insights into this matter at all. And I am left with the original court's decision: the break-in was staged. With that thought, and the inevitable conclusion it leads to: Knox and Sollecito might well be guilty.

Two closing remarks

In closing, a first remark to make is this. I am sure that anyone absolutely convinced of the innocence of Knox and Sollecito may at times have found some of the things I wrote surprising and perhaps quite contrary to what  they themselves hold true.

Bear in mind, though, that both my series (The Trial in Perugia and Back To The Drawing Board) are based on the verdicts given and the legal arguments they contain. They are not based on other considerations (and, let's face it, there are many other such considerations to be found). In particular, I have not and will not address the question as to how on earth a young girl from the US or a young man from Italy would suddenly decide to commit a horrible crime with a man they barely knew. That is certainly a fair question, but it is not one that I feel in any way equipped to answer.

The second remark is a simple one: in all of this, let's not forget Meredith Kercher.

____________

*  For a more mathematical approach, see my follow-up post, Doing the Math.

** The Italian criminal code allows for the cassation of earlier verdicts in cases where that earlier verdict contains "manifest illogicality of the judgment reasoning" (Article 606, Criminal Procedure Code).

5. The Meredith Kercher Case - Back to the Drawing Board (Part Five)

Introduction

I started out this new series because the Italian Court of Cassation recently quashed the Appeal Court's acquittal of both Amanda Knox and Raffaele Sollecito.

In Parts One through Four, I talked about the Appeal Court's decisions pertaining to the break-in, the DNA evidence with regard to the "double-DNA" knife and the bra clasp, the footprint on the mat in the small bathroom, and the traces found by the use of Luminol.

In this part, I'll run through a number of remaining issues. I'll try to do so quickly, though, because I don't really think any of them (with the possible exception of the mixed DNA traces in the small bathroom) is absolutely crucial to the case. In other words, I do not feel that the Court of Cassation's decision was based predominantly on any of these issues.  

The testimony of the various witnesses

During the course of the original trial, a number of witnesses was heard. These include, amongst others, Curatolo, a tramp who may or may not have seen Knox and Sollecito in a small square quite close to the house at the Via della Pergola late in the evening of November 1st 2007. They also include Quintavalle, the owner of a shop who may or may not have seen Knox in the early morning of November 2nd. 

In all these cases, the original court believed the witnesses and attributed weight to what they said. In all these cases, the Appeal Court disagreed.

I mention the testimonies of Curatolo and Quintavalle in particular, though, since what they said give lie to Knox's assertion that she and Sollecito spent the entire evening, night and early morning at Sollecito's apartment.

In the case of Curatolo, the Appeal Court decided that his testimony was unreliable because he well have gotten his dates mixed up. He testified about seeing Knox and Sollecito, but also about seeing people "wearing masks" and buses going to and from the square where he was sitting. The reference to the masks and buses would seem to indicate that he was remembering the evening of October 31st (Halloween), and not November 1st.

In the case of Quintavalle, the Appeal Court considered that this witness had only come forward a year after the murder took place, whilst he also testified that Knox had been wearing a grey coat when she entered his shop (a garment she didn't seem to own).

In both cases (in fact, in all the cases where witnesses gave testimony), I would consider the Appeal Court's decision understandable, and therefore valid. It might not necessarily be the right decision, but then, the same could be said of the original court's deliberations. In the end, of course, any court will have to determine for itself whether a particular testimony does or does not seem reliable; they are few real - strict - rules here. As a result, I doubt the Court of Cassation will have quashed the Appeal Court's acquittal based on that court's decision when it comes to the witnesses. 

The other traces in the small bathroom

In Part Four, I already discussed the footprint found on a mat in the small bathroom.

Other traces were found in the bathroom, though. In particular, there were blood traces clearly left by Kercher's blood. And then, more importantly, there were two traces which contained blood and the mixed DNA both both Knox and Kercher, found in the sink and the bidet respectively.

Both these traces appeared to have been left by diluted blood; that is, by blood mixed with water that had started to descend down the sides of the sink and bidet respectively. In both cases, the original court felt that it could reasonably be supposed that the traces were left by Knox, who, having Kercher's blood on her body, went to the bathroom to wash her hands (the trace left in the sink) and her feet (the trace left in the bidet).

The Appeal Court does not dispute the mixed DNA traces as such, nor does it dispute the fact that the blood was Kercher's. What it does dispute however, is that the fact that the traces contained mixed DNA is of any importance. Since the small bathroom was used by both girls, it is, according to the court, hardly surprising that Knox's DNA was gathered as well, especially given the rather large areas swabbed to take the samples.

I find these considerations quite understandable, but I'm not at all sure whether they're the correct ones to make.  It would seem to me to be, not so much a question of whose DNA was present, but rather whose DNA was absent. After all, say that Knox and Sollecito are innocent and that it was Guede and Guede alone who killed Meredith. It would then have had to have been Guede who entered the bathroom and washed his hands and feet. And yet, no trace of his DNA was found. Traces of Kercher were found, traces of Knox were found, but from Guede, nothing. I don't know - I'm no DNA expert - but I find this quite unlikely. I would assume the process of washing would entail a certain scrubbing of hands and feet, and, therefore, the very real probability of exfoliation. I would therefore presume that chances of Guede having left some of his DNA along with Kercher's blood would be high, certainly if we're talking about two separate places (sink and bidet) and certainly if the areas swabbed were relatively large.

As an aside, I point out that Sollecito's DNA wasn't found either. Does that mean anything? Well, not really. If it wasn't Sollecito who left the footprint on the bath mat, then yes, that would mean that there's no evidence he ever entered the bathroom at all, let alone that he entered after Kercher's murder. But the fact of the mater is that we do have the footprint. If he did enter the bathroom after the attack, could his presence, apart from that print, have remained undetected? Well yes. If, for example, he went in to take a shower (whilst Knox washed herself at the sink and bidet), that could very well have happened. Remember that the bathroom - well, at least to my mind! - would have been cleaned, if not very all too well. Remember, too, that Knox took a shower herself the next morning.

If my view on this is correct, it would appear that the Appeal Court's decision on this issue is illogically reasoned; it simply has taken the wrong facts into account.

The time of death

I will be brief as to the time of death. Forensically, it is impossible to establish at which more or less precise moment this occurred.  To try to decide that issue, other factors must be taken into account.

However, these other factors are the very ones which, by themselves, could be considered debatable. In particular, there is the testimony of the witnesses. If one believes their testimony, the time of death would have had to be around 11:30 pm (which is what the original court assumes). If one does not, the time of death could have been earlier, at, say, 9:30 or a little later (which is what the Appeal Court holds, stating that Kercher died "certainly not later than 10:13 pm").

There is, perhaps, one further thing to mention here. The Appeal Court attempts to set the time of death, in part, by interpreting (telephone) messages originating from Kercher's phone. At 10:00 o'clock, a number is dialed from Kercher's phone, and it's the first number in the phone's contact list. The number is that of the Abby Bank, and no international prefix had been added to the stored number. Now obviously the bank would not have been available at the time, and besides, the absence of the prefix meant that the call wouldn't have gotten through anyway. At 10:13, a GPRS internet connection is realised, which lasts all of 9 seconds; this might be in relation to an incoming message, but the duration is such that, if so, that message was not received. This could, the Appeal Court finds, be explained by "an involuntary connection or by a sudden interruption".

I must admit that I find both the call and the internet connection to be of no real value at all in determining the time of death. Who on earth knows what happened? Was Kercher playing around with her phone? Had she already been murdered and was the murderer fiddling around? Who knows? Such little factoids offer no basis on which to build any convincing hypothesis as to when Kercher died, and in any case it is clearly absurd to state, as the Appeal Court does, that the Kercher was "certainly" dead by 10.13 pm.

Knox's and Sollecito's alibi

According to Knox (Sollecito did not testify at the trials), she spent the night of November 1st to November 2nd at Sollecito's apartment. They had eaten late, around 23:00 pm, and when she awoke the next morning, at around 10.00 am, Sollecito was still asleep. She went to the Via della Pergola to take a shower and change her clothes.

The original Court did not believe this. It pointed to the testimonies of Curatolo and Quintavalle, but also to the following:

• Knox had turned her mobile phone off. It should be assumed that Sollecito did likewise, since his father sent him an SMS at 11.14 pm that was not received by Sollecito's phone until 6:02 am the next morning;
• Sollecito’s father called his son around 8:42 pm, during which call Sollecito said he had just been washing the dishes. From this, it can be inferred that Knox and Sollecito had eaten by then;
• there was no activity on Sollecito's laptop from 9:10 pm onwards till 5:32 am;
• that Knox awoke at 10.00 am seems odd, given the fact that she was an early riser and that she and Sollecito had been planning to go to the town of Gubbio that day;
• that she stated that she returned to the Via della Pergola to take a shower seems equally odd, since she also stated that she had taken a shower at Sollecito's apartment the night before. 

The Appeal Court dismisses the original court's views. As I have already stated above, it does not accept the reliability of the statements made by Curatolo or Quintavalle. As to the other points mentioned by the original court, the Appeal Court accepts the underlying facts, but does not deem them to be of any relevance.

Perhaps (the Appeal Court notes) Sollecito had told his father at 8:42 pm that he had been doing the dishes, but that does not imply that they had already eaten. Perhaps there was no activity on Sollecito's laptop, but that does not imply Knox and Sollecito weren't there. Perhaps the SMS message his father sent wasn't received till early the next morning, but that doesn't imply that Sollecito, too, had switched his phone off; the reception in parts of the apartment was bad. Perhaps Knox had showered the evening before, but that doesn't mean she might not have decided to take a shower at the Via della Pergola (after all, the main reason for returning to her own apartment might have been to change her clothes).

It seems to me that, on the whole, the Appeal Court's approach to Knox's alibi rather misses the point. The original court, when looking at that alibi, effectively pointed out that it was unconvincing; that is, it offered no proof that Knox and Sollecito could not have committed the murder. It went on to point out a number of particularities which made Knox's story not simply unproven, but also unlikely or, in one case at least, demonstrably untrue.

What the Appeal Court seems to want to do is to establish that Knox's alibi, by and large, is not so untrustworthy as it might seem. I think it fails in this, but that also, in doing so, it more or less misses the point. Consider: if a suspect gives an alibi, he is effectively saying "look, I couldn't have done it, because ..." (and he will then give his reasons). The burden of proof is, in this case, on him. If the alibi is strong, if it can be relied upon, he will not be prosecuted successfully; if, on the other hand, the alibi is unconvincing (if it cannot be relied upon), well then, it offers no proof that the suspect did not commit the crime.

The same applies here. The original court, to my mind quite correctly, decided that Knox's alibi helps neither herself nor Sollecito. None of what the Appeal Court says with regard to that alibi change this; nothing the Appeal Court says does anything to prove that the alibi should be considered true. As a result, the Appeal Court's reasoning is, at the very least, inconsequential.  

At worst, though, it is just downright wrong.

Take, for example, the 8:42 pm telephone conversation between Sollecito and his father. This is what the Appeal Court says:

"And indeed these are his father’s statements on the matter in the course of his testimony (hearing of 6-19-2009): “…he told me if I’m not mistaken that evening of the call that  water had, that while he was washing the dishes or doing something in the kitchen water had spilled on the floor, this is right…”
And again: “…that he was at home and was messing around in the kitchen and this problem had happened, basically. That he realized while he was washing the dishes that water was spilling on the floor…” Hence there is no talk at all about dinner being already finished."

But this is what Knox herself had stated (according to the original court):

"Therefore, she stayed with Raffaele, with whom she smoked some marijuana. They had dinner together, but quite late, perhaps 23:00 pm. 
After dinner, she noticed a bit of blood on Raffaele’s hand and had the impression that 'it had to do with blood coming from the fish‛ that they had cooked. Raffaele, after having eaten, had washed the dishes, but a break in the pipes had occurred under the sink. And water was leaking, with flooding on the floor."

Now it is quite clear that both Sollecito's father and Knox are referring to the same thing: washing the dishes, at which point a pipe broke under the sink. But according to Knox herself, this happened "after dinner".

So it becomes quite incomprehensible that the Appeal Court would nevertheless surmise that Sollecito had been washing the dishes before dinner. 

In the end, of course, the only possible conclusion is that Knox's alibi is false when it comes to the time she had diner with Sollecito. They didn't have dinner "quite late, perhaps 23:00 pm"; they had already eaten by 8:42 pm. The Appeal Court's suggestion that this could nevertheless be different is clearly not based on all the facts.

Conclusion

So, where does all this lead us? Well, as stated, I feel that most of the aspects raised in this part of the series are not in themselves decisive. There are certainly questions to be raised as to Curatolo's and Quintavalle's testimonies, but they are not absolutely essential to the case. The time of death cannot be established forensically; both courts agree on this. As to Knox's alibi, well, the Appeal Court falters in trying to waylay the original court's findings, but this, too, is not in itself terribly conclusive.

The Court of Cassation, to my mind, will not have based its decision on any of these issues.

The possible exception to this may be the mixed DNA traces found in the small bathroom. These traces could quite possibly be considered crucial, and the Appeal Court's reasoning on this may well have been considered unacceptable.

4. The Meredith Kercher Case - Back to the Drawing Board (Part Four)

The evidence gets really confusing....

Introduction

I started out this new series because the Italian Court of Cassation recently quashed the Appeal Court's acquittal of both Amanda Knox and Raffaele Sollecito.

In Parts One through Three, I talked about the Appeal Court's decisions pertaining to the break-in and the DNA evidence (the evidence with regard to the "double-DNA" knife and the bra clasp).

In this part, I'll start to wrap things up by discussing the most interesting other aspects of the Appeal Court's ruling. I will focus on the footprint on the bathroom mat - which inevitably leads one to evaluate whether or not a clean-up operation took place -  and the traces left by  Luminol found in various places in the apartment at the Via della Pergola.  

The print on the mat and the clean-up

In the smaller of the two bathrooms in the upper floor of the house at the Via della Pergola (the bathroom used by Kercher and Amanda Knox, just next to Kercher's bedroom), a mat was found on which the imprint of someone's bare right foot was found. The print was made due to the fact that the foot has been bloodied; the blood was Kercher's.

The original court, after having heard the expert testimony from both the prosecution and the defence, decided that the footprint matched the right foot of Sollecito.

The Appeal Court rejects this, coming to the conclusion that the print is "of no evidentiary value against defendant Sollecito". In fact, the court states: "It cannot (...) be ruled out that Guede (...) experienced the loss of his right shoe in the course of the violent aggressive manoeuvres to which he subjected Kercher, thus resulting in the soiling of his foot with blood, which he took it upon himself to wash in the small bathroom situated immediately to the left of the door to Meredith’s bedroom. Otherwise, his right shoe should also have left some kind of bloody trace along the corridor as he exited; he likely went through it, however, with his right foot bare, even if cleaned of blood by this point."

Now before addressing the forensic evidence regarding possible matches of the footprint, there is another issue to bear in mind. Is the fact that print existed in the first place of any relevance for the question as to whether more than one person was involved in the murder?

Well, if we consider the Appeal Court's reasoning, as quoted above, one might assume that something along the following lines must have happened: 

•  sometime during or preceding the attack on Meredith, Guede loses his right shoe;
• Guede kills Kercher, doing so in such a manner as to inevitably leave considerable amounts of her blood in her room and, no doubt, on his person. He also leaves evidence of his presence in her room (there is, for example, the imprint of his bloodied hand on a pillow). He then goes to the bathroom to wash his bare foot;
• he then cleans up, thereby forgetting or not noticing the single footprint on the bathmat (and, indeed, the hand on the pillow), and possibly puts his shoe back on (or perhaps, as the Appeal Court assumes, he does not);
• and he then departs, leaving, however, a discernible trail of shoe prints from his left shoe.

If one accepts such a sequence of events, a clear problem arises. After all, if you wish to believe that the same person (i.e. Guede) could have left both the footprint on the mat and the shoe prints, you would have to accept that that person would have had to be, at one and the same time, cautious enough to have cleaned up after the attack (and even, at least to a certain extent, to have "rearranged" the crime scene), but careless enough to ultimately walk out of the apartment with a clearly bloodied shoe (and the mark of his hand on a pillow). He would have had to spend considerable time and attention to trying removing his presence in some ways, whilst at the same time not caring at all whether his presence was discernible by other means. (I should perhaps at this point bring into recollection that the shoe prints leading from Kercher's room to the exit were visible to the naked eye; these were not traces only discernible by the use of Luminol.)

In other words, it seems fairly clear that the two sets of actions could not have been taken by one single person. They are, simply put, contradictory in nature. To a certain extent, the Appeal Court itself inadvertently strengthens this contradiction, when it assumes that Guede left the apartment wearing only his left shoe, with his right foot still bare. That, certainly, is the action of someone who wants to leave as quickly as possible, and not the action of someone who has decided, instead, to stay for a while and remove as much evidence as possible. Besides, it seems rather absurd to suppose that Guede would have cleaned up the place whilst wearing just one shoe.

The Appeal Court however, recognises the problem, and deals with it in a way that is quite crucial not just to the issue of the footprint on the mat but also to the issue of the traces revealed by Luminol (which I'll discuss later). It does so by assuming there was no clean-up.

I must admit that when I first realised this, I was momentarily at a loss for words. That the apartment had, at least partially, been cleaned after the attack had been, for me, a given (as it had been for the original court, which stated that "a cleaning activity was certainly carried out".)

The Appeal Court's reasoning on this cannot be found in its deliberations concerning the footprint; it is only when one arrives at the court's reasoning with regard to the traces left by Luminol that this aspect of the ruling becomes clear. There, the court expressly rejects the idea that any clean-up took place: "the occurrence of a clean-up is negated by the sheer number of traces found in the house", the court states.

I must admit I have no true understanding of how the Appeal Court might find this to be the case. If Kercher was murdered in the way she was murdered - that is, stabbed repeatedly with one or two knives - she would have lost a considerable amount of blood. Whoever attacked her must gotten that blood on them; the blood must have gotten on their (bare or shod) feet. Of course some sort of clean-up took place, and this follows from the simple fact that the very next day, various people (not just Knox and Sollecito, but also Romanelli, a friend of hers and both their boyfriends, along with two officers from the Postal Police) all entered the apartment and none of them, at that point in time, realised that they were walking into the scene of a violent murder. It follows from Knox's own testimony: she states she had earlier taken a shower and not realised anything was actually wrong; she noticed on or two little blood stains but assumed someone had had her period. And, certainly, it follows from the single footprint on the bath mat in the small bathroom, with the absence of any other prints leading from Kercher's room to the bathroom and the mat.  

In short, if the fact that some sort of clean-up had taken place seemed, to me, a given, that is because it is. I don't see how you can get around that at all; any other idea would appear to be totally illogical. Nevertheless, that is the assumption of the Appeal Court, and because of this, I feel that that court's reasoning is seriously suspect.

Now, I have already said that, if you do assume a clean-up took place, this also implies that the Appeal Court's reasoning with regard to the footprint on the bath mat becomes clearly illogical.

*******

It is only when the above issues has been addressed that the next question arises, which is whether or not the forensic evidence shows if the print matches Sollecito's foot. As to that question, I will try to be brief. The reason is very simple: I'm basically at a loss.

You see, the experts of the police came to the conclusion that the print was compatible with Sollecito's foot, but incompatible with Guede's.  However, the expert hired by Sollecito, professor Vinci, disagreed: he stated that the print could, indeed, have been left by Guede. To substantiate this, Vinci made one very important assumption, which is that the print of the foot's big toe is actually not a print of just that toe, but also a print of the next (or second) toe. The print is therefore merged; it's two toes. This is important because it turns out that Sollecito's big toe is actually much bigger than Guede's. In other words, to explain the size of the print when it comes to the big toe (to explain that the print could nevertheless be Guede's), the defence had to assume that the print was two toes.

Now the original court rejected Vinci's claim, using a rather simple argument: it stated that the print was clearly homogenous. If it had been the merged print of not one but two toes, there would have had to have been some incongruity, some "interruption of continuity" (as that court states) in the print. However, there is none, the court alleges.

The Appeal Court , however, states the opposite, where it confirms that "examining the black and white images [in professor Vinci's report], one remains convinced of the validity of his belief."

And that's basically it. In other words, the original court looks at the print and decides it's Sollecito's foot, whilst the Appeal Court looks at the print (the photos in Vinci's report) and decides that it could well be Guede's.

As a result, I have no clear idea of which court's opinion is the more valid. I can only turn to a few rather vague ideas and notions. Whilst these, by and large, would seem to indicate that, yes, it's rather more likely that we're talking about Sollecito's print than Guede's, that's just not enough.  

As to what the Court of Cassation made of this, once again I don't know. From a strict legal point of view, I would have to assume that that court might well have had to accept the Appeal Court's reasoning, since it doesn't seem to be overtly illogical or insufficiently substantiated. 

Please remember though, that we are only talking about possibilities (or probabilities). Neither the original court or the Appeal Court rules out in any absolute sense that the print could have been made by either Sollecito's or Guede's foot. As a result, the remarks I made earlier - regarding the relevance of the print when it comes to the question of a "lone wolf" criminal - remain quite intact, as do my comments regarding the clean-up. And these, to my mind, are the central issues.

*******

Sollecito's foot

Guede's foot

 

Click on either image for a larger picture.
As to the footprint on the mat, here are the measured sizes: Big toe height = 39. Big toe width = 30. 
Metatarsus height = 50. Metatarsus width = 99. 
(The photos are from the prosecution's report.)

*******

The Luminol prints

As the Appeal Court correctly states, during the second inspection of the house at the Via della Pergola, on the 18th of December, 2007, Luminol was applied to the floor of the corridor, to the kitchen/living-room, to the bedrooms of Knox and Filomena Romanelli, and, finally, to the larger bathroom.

Now, Luminol is a substance that can detect the (invisible) existence of blood, but it reacts equally to other substances, like fruit juice or bleach.

The use of Luminol revealed various traces (I believe there were six traces in all). These traces were further examined; that is, they were, firstly, examined as to whether it could established that they were left by blood. Secondly, DNA samples were taken and tested.  

As for the blood sample testing: all the results came up negative. It could not, in other words, be established that the traces were blood traces.

As for the DNA testing: two traces were found to contain the mixed DNA of both Knox and Kercher. One of these traces had been taken in Romanelli's room; the other had been taken in the hallway. The other four traces did not contain mixed samples, but they did contain the DNA of just Knox.

The original court, in considering this outcome, came to the conclusion that in the case of the two mixed samples, a reasonable supposition is that these traces consisted of the blood of Kercher, mixed with the DNA of Knox. In doing so, that court takes into consideration that whilst the testing done did not establish the existence of blood, there was no sufficient reason to exclude the possibility that they had, nevertheless, been blood samples.

The Appeal Court disagreed, stating the following: "First and foremost, the certain, true fact is that the generic blood test gave a negative result. According to the [first] Court this happened because of the scarcity of the available biological material, but the consultant for the defense, (...) specified (....) that the (...) test is very sensitive, so much as to give a positive result even with only five red blood cells present. Dr. Stefanoni herself, moreover, clarified (...) that, while a positive test result could be deceptive due to reactivity of the chemical with other substances, a negative result gives certainty that no blood is present."

The first thing that should be noted here is that the Appeal Court has muddled its facts. Dr Stefanoni (who is attached to the Scientific Police and therefore the prosecution) was, at the time, clearly talking about the results from the use of Luminol, not the results from specific and subsequent blood tests. And her remarks seem correct: a negative Luminol test will no doubt be conclusive (i.e. if the Luminol does not cause a reaction, well then, no blood, or any other substance that reacts to Luminol, will be present). This, however, clearly does not apply to the six traces in question, since all these traces led to positive Luminol results; there was a reaction. 

What we are left with is the true statement that the specific blood test lead to a negative result. Here, however, the same applies as when examining the "double-DNA" knife and the bra clasp: the fact that it could not be established that Kercher's DNA sample on the knife was left by blood, or Sollecito's sample on the clasp was left by his handling of the clasp, does not in itself rule out either possibility.  It simply means that the answer to that question must be sought elsewhere, by different means.

The means by which the original court reaches its answer is relatively straightforward. We have, that court considers, the positive Luminol samples. Then we have, in two cases, further DNA samples that were mixed (they contained both the DNA of Knox and Kercher).  What is the most reasonable explanation for this? Well, the original court states, it's surely that Knox, in her bare feet - feet still bloodied with Kercher's blood - left these traces.

To which it can be added that one of the traces (the one in Romanelli's room) does not seem attributable to a bare foot (it is simply amorphous). The second trace, however (the one found in the corridor), does seem to have been left by a foot (indeed, it seems to have been left by Knox's foot).*

And to which it can further be added that any other explanation seems much more improbable. In particular, the notion that the two mixed traces could just be evidence of the fact that both Knox and Kercher happened to live in the same apartment seems unlikely. After all, such an idea would necessitate that , at two very specific places and at more or less the same time, Knox and Kercher both left their DNA traces, and you would further have to assume that, again at the same place and at more or less the same time, some innocuous substance with which Luminol reacts (such as fruit juice or bleach) was used. If you assume that substance to have been incidental, such as, say, spilled fruit, common sense dictates that the odds of this having happened become very high indeed; if, alternatively, you presume a much more generic substance caused the reaction, such as bleach, the opposite apples; it becomes almost impossible to understand why only two traces were found.

In other words, the original court reached its decision on the basis of a fairly logical set of thoughts, and one that I, at least find compelling.

It is interesting to note that the Appeal Court seems to have all sorts of difficulties in trying to reach an opposing view. The court starts by assuming the Luminol traces could indeed have been caused by bleach. After all, why not? There were four young women living together in the apartment, who must have had friends coming over regularly; bleach must have been used often. In doing this, however, the Appeal Court is already starting to miss the crux of the matter; after all, it is not just the positive Luminol test that is indicative, it is the combination of that test and the DNA sampling, and the fact that so few traces were found, which is important.

Perhaps because of this, the Appeal Court goes on to make two further remarks. Firstly, it states the following: "The limited number of footprints detected can be explained by treading at different times and by the use of bleach on points specifically dirty.  After all, doubts similar to those raised in the ruling could be brought up even supposing that the traces are of blood: why only in those few points, moreover not consecutive and instead spread in various rooms?"

This quotation is, it must be said, truly odd. If the traces were a reaction to bleach, surely there must have been a lot more of them. So the Appeal Court is trying to explain why there were, in fact, so few. And in doing so, it immediately ties this issue to another one altogether, which is the question of why only two mixed DNA samples were found.

Well, that question has already been answered by the original court, and that court's answer was simple: a clean-up operation had taken place. So one would expect the Appeal Court to concur, this, after all, explained the conundrum the Appeal Court itself had just made obvious.

What, however, does the Appeal Court do? It immediately and rather astonishingly rejects the idea of a clean up. The second remark it makes is: "the occurrence of a clean-up is negated by the sheer number of traces found in the house".

It is at this point that one must seriously consider that the Appeal Court has more or less lost the ability to think straight. The court starts its arguments by asking itself why there are so few footprints. It links this to the fact that, well, there are only two mixed DNA traces, too. It then offers the answer to the question of how this can be the case: there must have been a clean-up. It then rejects that notion. And how does it do this? By pointing to "the sheer number" of traces.  I think the only correct response to all this would be: "Eh?"

Having said this, however, I must point out that the Appeal Court, after this momentary lapse of reason, comes back quite strongly. It finishes its arguments on the traces left by Luminol with a simple and possibly adequate remark, stating that the DNA in the mixed samples was once more so small that LCN testing was required. And just like the testing done with the knife, serious questions can be raised as to the reliability of the results procured. Once more, the question arises if the tests conducted by the Scientific Police were adequate since, once more (as the Appeal Court states), just a single test was carried out (and, as far as I know, no new testing - done, perhaps, on the basis of methods "still in development" - can be done). 

So, how will the Court of Cassation have thought about all this? Well, at the very least I would assume that it could not have overly pleased with the Appeal Court's considerations; these are, in many ways, clearly illogical in very substantive ways.  Of course some sort of clean up seems to have taken place; the Appeal Court's negation of this makes very little sense at all. So of course there is the very real question as to whether Guede could and would have engaged in this clean up and if not, if that fact alone does not clearly point to the guilt of Knox and Sollecito. And of course the traces left by Luminol should be taken seriously in this regard. And yet, there remains the unclear answer to the question of whether or not the footprint on the mat should or should not be attributed to Sollecito. And there remains the question of whether the results of the LCN testing on the mixed samples can or cannot be considered reliable. And I am uncertain as to how the Court of Cassation has answered either of these questions. 
 ________ 

* This paragraph was edited on the basis of the comments you can read below. Originally, I had stated that both prints were attributable to bare feet, thereby following the Appeal Court's statements. The Appeal Court seems to have been wrong, though.