March 8, 2010

Methods of the Polizia PseudoScientifica A Knife, a Clasp, a Glow

When one examines the methods of the Polizia Scientifica in the Knox/Sollecitoinvestigation, they appear to have been, not merely unscientific, but pseudoscientific. That means pretend science, it is not the real thing. We see this, because a consistent pattern emerged.

It was not a pattern of innocent mistakes, made under the stress of time, although there were plenty of those. Neither was it one of incompetence, for these people mostly knew what they were doing. Neither did it appear, for the most part, to be blatant framing by splashing blood, planting evidence, or manufacturing data. That type of lie would have produced clear results, and might also have  left clear tracks. These results are anything but clear. And who wants to leave tracks? Certainly not the Polizia Scientifica.

What appeared to be the pattern, the modus operandi, in the Knox/Sollecito trial is something like this: The Polizia Scientifica plucked an item from the field.  They subjected it to some sort of “scientific” testing. Then they “cherry picked” the results, and presented these selected results in the complete absence of anything to compare them with. That is, without any control experiments. This modus operandi is compatible with pseudoscience. It appears to be an attempt to create the appearance of scientific certainty, while producing absolutely unscientific results. Who were they trying to fool? The judges and jury.

“...pseudoscience is any subject that appears superficially to be scientific, or whose proponents state that it is scientific, but which nevertheless contravenes the testability requirement...”   http://en.wikipedia.org/wiki/Pseudoscience

What is this “testability requirement?” It means that if you can’t test it, if you can’t repeat the experiment to see if it happens again, it isn’t science. It is pseudoscience. Take the kitchen knife DNA. The testing performed by Stefanoni destroyed the sample. Not a trace was left. Her experiment cannot be tested, cannot be reproduced. It can never be checked to see if it was a real result, or a fraction of a flyspeck of contamination from her lab.  It was, “I did this experiment. These are the results. Trust me.”

Here’s the procedure in more detail. Follow along. There will be a quiz at the end of this chapter.

Step 1: Collect some stuff from the crime scene, or thereabouts. A kitchen knife, a clasp, a Luminal glow. No need to be picky here. It’s not the item itself, it’s the science you do to it that makes it cry “guilty.” That’s why it didn’t matter that the kitchen knife was a randomly chosen implement. A can opener from Raffaele’s drawer would probably have Amanda’s DNA on the handle, it just wouldn’t sound as impressive.

Step 2: Perform tests on the item. What kind of tests? Scientific Tests, of course. The tests need to have the veneer of impressive, and barely comprehensible science upon them. For this, DNA profiling cannot be beaten.

Step 3: “Cherry pick” the results. This means, pick the ones that support your theory, and leave the ones that don’t. Don’t like a result? No problem. Don’t report it. Discard those DNA peaks that don’t fit. Didn’t find anything that incriminates the defendant? No problem. Go back 47 days later, and pick up some more stuff from the scene.

Step 4: Present these results floating freely in an ominous air of suspicion and guilt. Leave out any kind of reference, any kind of comparison that might show how uninformative and mundane they really are. Avoid, in other words, any kind of control tests.

Now you have the impressive sounding results to support the prosecutor’s tales.

Let’s talk some more about control tests, because this is such a fundamental matter, that it is often lost in the grass. An experiment without a control is like a thermometer without a scale. You see the mercury inside, but you have nothing to compare it with. There are two choices at this point. You can understand that it is meaningless, it is data without context, or, you can point at it and make up any temperature you want.

“Scientific controls are a vital part of the scientific method, since they can eliminate or minimize unintended influences such as researcher bias.” http://en.wikipedia.org/wiki/Control_experiment  

Careful scientists take steps to keep their own researcher bias from influencing results. They perform double blind experiments, for instance, in which even they don’t know which specimen is which, to prevent themselves from knowing what the results “should be.” That way, when they get a result, they can trust it, because they know they didn’t unconsciously choose it.

Let’s walk through the Polizia PseudoScientifica process for three critical items.

A Knife
The kitchen knife was retrieved from Raffaele’s kitchen drawer some 5 days after the murder. It was reportedly taken to the police station, sat on a detective’s desk for a day or so, and then was mailed to the lab in Rome in an ordinary box. Hardly the kind of careful handling you would expect of evidence slated for conventional DNA testing, let alone the hypersensitive LCN profiling. The blade DNA profiling was performed by an improvised, non-reproducible, never-validated method with deficiencies described in detail in the chapters on LCN DNA. In fact we can add extremely poor evidence handling to the list of 9 deficiencies compiled there to make it 10 testing deficiencies.

The low copy number test on the kitchen knife was performed without any negative controls. In negative control tests you perform the DNA multiplication and profiling, without adding any sample to the system. Often when this is done, as if by magic, a DNA profile emerges. It has come from a minute amount of contamination from the equipment, or the laboratory. These negative controls are essential to performance of LCN work, as shown in Chapter ##. It does not appear that they were performed by Stefanoni. I have to say, “does not appear” because the documentation of what was done and what was not done has been consistently withheld by the prosecution and the Scientifica Polizei.

Perhaps even more important for the knife DNA, no control experiments were run to follow the handling of the item from the field through to the laboratory. That is, to see if other, random objects retrieved from the same drawer and handled in the same, unprofessional way, might also appear to have DNA on them. It would be interesting to hear the prosecution spinning a sinister implication out of DNA found on a can opener. Perhaps one can use canned peas for satanic rituals. Would Meredith’s DNA be found on a spoon from the same drawer? How about Filomena’s? Would the spoon then be cast as the murder weapon, whether  it matches any wounds or not?

All this is preposterous of course. But think about it. We have no way of knowing what the supposed knife DNA means, or where it came from, because no comparison tests of any kind were performed.

A Clasp
The only trace of Raffaele Sollecito’s DNA found at the girl’s apartment during the main searches for evidence was on a cigarette butt that was not in Meredith’s room. No trace whatsoever was found in Meredith’s room. No DNA, and also no footprints (see the Footprint chapter), no fingerprints, no nothing. The reason is simple. He was never in Meredith’s bedroom. Not during the murder. Not ever.

This awkward fact placed the polizei and prosecution in a difficult position. They had already declared victory in the case. They had raced Amanda and Raffaele off to prison with their horns blaring in triumph. They had posted their pictures on a wall along with mafia bosses they had captured. How embarrasing then, that when they actually got around to looking for evidence against him, they found nothing.

Faced with this total lack of evidence, the polizei sprang into action. Forty seven days after the murder, after teams of researchers had completely trashed the crime scene, rearranging everything, piling things onto beds, filling the wastebaskets with their discards, shoving furniture and carpets around on the floor, they sent another team  with a clear mission. Get Raffaele. 

What would happen to any random object left on the same floor and kicked about for 47 days? Especially an object with cloth attached , making it a virtual dust mop. It would be covered with dust, and the DNA that comes with that dust. Raffaele was at the apartment visiting Amanda on several occasions. The presence of his DNA there means nothing.

Control experiments to check for this would have been simple. The clasp was retrieved from a pile of debris, shown in the picture, left by the fastidious investigators in Meredith’s room. Testing a few other items from that pile to see if they, too, had picked up DNA dust from the floor would tell us whether there was anything special about the clasp. Of course, that wasn’t done.

So we have “Raffaele’s DNA was found on Meredith’s bra clasp,” rather than, “Raffaele’s DNA, along with DNA from lots of other people, was found at various random locations throughout Amanda’s apartment, which he visited several times before the murder.” The first phrase sounds incriminating. The second, accurate phrase, shows how meaningless this test result is without a control experiment.

The handling of the clasp when it was retrieved from the scene is shown in the linked video. The investigators, dressed in fancy white outfits, seem to play some kind of game with it. Why the outfits? They do nothing to prevent mixing contamination of the material at the scene. As shown in the closeup picture, the outfits, and their gloves, quickly become contaminated by DNA from various sources at the scene which can then be transferred to the evidence.

But contamination, inevitable as it was in a snip of fabric kicked around on the floor for a month and a half, buried under a throw rug and pulled from a pile of debris, may not be the whole story, or even the real story of how Raffaele’s DNA came to be found on the bra clasp.

Raffaele’s DNA profile was reported to be on the bra clasp, retrieved in the 47 day delayed sweep, but, interestingly, it was not on the bra itself. It was nowhere else, in fact. How could his DNA wind up clearly turning up on the clasp, but not appear on the bra? This is nearly impossible to account for if it occurred as a natural consequence of the commision of a crime. But it makes perfect sense if Raffaele’s DNA was on the bra clasp because it was put there.

Try a kind of a “thought experiment” to sort this one out. First, leave the 47 days out of it. Assume that the clasp was recovered along with everything else, a day or so after the crime. The bra in one bag, the clasp in another, etc. DNA is extracted from various places on the bra, and from the many other items retrieved from the room for analysis, and also from the clasp. They are profiled.

Raffaele’s DNA profile does not show up anywhere on Meredith’s bra. It does not show up anywhere on any of her other clothing items. It doesn’t show up anywhere, on any item in Meredith’s room, except one.. It shows up on the bra clasp. What a strange thing this is! Rather hard to believe, in fact. How could he possibly have participated in the murder, been present during a violent, protracted attack and murder, and wound up leaving his DNA on one, and only one item of evidence? How could Raffaele have put his DNA on the clasp, but not on the bra itself? It doesn’t make sense.

Now remember the 47 days. The bra clasp wasn’t just a random item. It is the prime item that was retrieved after the DNA profiling had come up negative for Raffaele on every other item. The dancing polizei proved that. It was the last hope, the only hope, for finding a trace of him. The last hope for coming up with evidence to incriminate someone who had already been declared guilty by the prosecution and the polizei. Lo! A miracle! It had his DNA on it! Wasn’t that convenient?

A Glow 
Luminol glowing footprints were found in a hallway, and some may have been Amanda’s, it is hard to know for sure because they were only compared with her feet, and found to be “compatible.” Again, no controls. Meredith, Laura, Filomena, none of the other resident’s feet were compared to these footprints. The footprints were tested for blood, and it came out negative. No blood. So, why are they important? Amanda lived there, after all.

Amanda’s DNA was said to be found in one of these footprints. Did they also test a meter away from the footprints, to see if her DNA was all over the apartment where she lived? No. That would have been another control experiment. Was the DNA actually associated with the footprint, or did it just happen to be there, because the resident’s DNA was all over their apartment, as people’s DNA usually is? We will never know. They skipped the control experiments, and presented results without any reference. It’s getting hot in here, look at that thermometer without any scale!

These are just three examples, there are many more. Enough to discern a clear pattern, that the methods of the Polizia Scientifica are compatible with pseudoscience, and are a consistent attempt to mislead the judge and jurors.

Now for the quiz:
1.  If you wanted to perform honest tests to search for truth, to learn what has really happened, would you exclude control experiments?  (Yes /No).

2. If you want to perform tests that appear scientific, but are actually intended to make an innocent person look guilty, would you perform control experiments?  (Yes/No)

3. Did the Polizia Scientifica perform control tests in the Knox/Sollecito investigation?  (Yes/No)

If you answered “No, No, No!” then you’ve got the point. If you didn’t, stop and think if you would like to be investigated with these same kinds of tactics.