Powerpoints #10: The DNA Evidence May Be A Tough Mole To Whack

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We will further see in this presentation what a tough mole to whack the DNA will be.

We have already covered in Powerpoints 7 the basics of DNA evidence. That presentation covers the definitions of valid and invalid DNA samples, how contamination might occur, who collected and analyzed the Perugia samples, and how the samples will have been stored.

DNA analysis has been done on the various luminol-enhanced footprints in the house that Kermit analyzed for us.  Also on the knife found hidden in Sollecito’s apartment, and on some items of clothing, and on some fittings and fixtures in Meredith’s house. And quite possibly on other items, too.

Here’s frequent TV legal expert Theodore Simon in the recent NBC Dateline documentary:

Theodore Simon thinks the prosecutors evidence made public so far is daunting. The defense could argue a faked robbery, and a moved body, and contamination, but eventually it could become like whack-a-mole and all of their arguments could lose force.

Theodore is far from alone. New York lawyers following the case reckon the odds of defense arguments losing traction because there are just too many evidentiary points are already high.

The defenses seem to be indicating that they will argue at trial that all of the many DNA samples might be too small, or too contaminated, or less than 100 percent of a match.

But nothing seems to stand out in the Perugia DNA process to suggest a major failing at any point. And if there was one, only scientific evidence in proof of this will influence the court, and innuendo will really go nowhere.

Posted by Nicki on 01/06/09 at 11:59 PM in

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Nicki, your clear description of how the DNA was handled is very comforting to me after all the wild claims. Thanks for the excellent work, I for one really appreciated it, and I’m looking forward to more.

Posted by Anne on 01/07/09 at 09:45 PM | #

Amanda was a suspect BEFORE the police found her DNA on the knife in her flat.  This is important.  If the police only had the DNA typing and they went out into the countryside like Cinderella’s prince they would find a number of people that matched the small DNA sample.  To pick a number let’s say 1 in 100,000.  You definitelt could not convict someone based on this.

However, if someone is a suspect and then you find her DNA on a knife in her flat, what are the chances?  It’s not whack-a-mole, it’s guacamole.

Posted by Arnold_Layne on 01/08/09 at 01:09 AM | #

Hi Easy Ed,

Amanda DNA is unique to Amanda, so unless she has a twin, the chances to find another human being with the same DNA are 1 out of billions. And BTW her DNA on Sollecito ‘s knife doesn’t have particular significance since she was spending a lot of time at her b/f apartment.

But you’re right when you say that she was already a suspect before her DNA AND Meredith ‘s DNA were found on the knife, since Meredith’s DNA had no business to be there. As a matter of fact, defense is not arguing Amanda’s DNA, but rather Meredith’s DNA on the blade.

Furthemore,the knife was not cleaned with common dish detergent but with bleach, a household practice surely uncommon even among those most concerned about hygene.This fact also adds importance to the knife evidence explaining why the number of cells found on the blade was small-but not small enough to prevent a PCR yielding a positive identification with Meredith’s DNA, as stated by the biologist in charge of the forensic lab.

Posted by Nicki on 01/08/09 at 01:52 AM | #

So why do the Knox/Sollecito supporters keep bleating on that this knife is not admissible and the DNA isn’t good enough to match Meredith?  Surely there is only one party who will look like fools come 16/01/09 and those people will have Seattle accents.  The hole is getting deeper for the suspects, I just cannot understand the mentality of these people, AK/RS really are delusional or they are being legally advised by the biggest optimists in Europe.

Posted by daisysteiner on 01/08/09 at 05:37 PM | #

Daisy, that’s such a problem with lawyers. Remember Biscotti thought he was going to pull a rabbit out of a hat for Rudy Guede.

Some rabbit.

The Knox-Mellases may have been way better served to have a cool-headed American lawyer advising them from this end of things, and acting as their front man or woman, than the bumbling public relations firm that seems to be driving their misconceived aggression.

Posted by Peter Quennell on 01/09/09 at 05:42 AM | #

This site is impressive in tone, detail, and complexity of analysis. Thank you for your work.
First, I want to apologize for bringing the conversation back around to the crime when you’ve done such a nice job in the last few days of memorializing Meredith, which is why I’ve buried my comment under an old post. I followed this case initially, but did not keep up with the trial and so am only now catching up. I live on the west coast of the U.S. and am troubled by the accusation that this case was fabricated by over-zealous police and prosecutors. Like other posters on this site, I find particularly disturbing the nationalistic tone of these accusations.
I am wondering if you might respond to a theory and answer a question: 1) I have wondered for some time if what occurred that night began as a prank that turned lethal. That theory seems unlikely now given the details of the viciousness of the crime which suggest it went well beyond some kind of prank-gone-wrong. But, anyway, could it be that Knox, and Sollecito did not realize Meredith was dead until they returned to the house? That when they fled the house they were unaware that she had been fatally wounded? Given the testimony of the man in the park, Sollecito and Knox waited until the broken down car was towed in which time it’s possible Meredith bled to death. Perhaps they then returned to the house and found her dead?  I don’t believe this would diminish their responsibility for her death. I only ask because it is still hard to believe that three people would collectively plan to murder.
2) I’ve read your account of the extensive clean up of the crime scene and it seems that where police didn’t find fingerprints is as telling as where they did. Has anyone documented the crime scene from that angle? A related question about the lamp from Knox’s bedroom found in Meredith’s room: Perhaps I’m missing a detail here, but as I understand it, no fingerprints belonging to Knox were found in Meredith’s room, or in Knox’s own bedroom. I take that to mean that none were found on the lamp that belonged to her. Is that the case?

Posted by profk on 12/10/09 at 04:01 AM | #
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