Why do you think that Dr Stefanoni should not have interpreted the peaks according to her training and expertise?
When crime scene investigators are in a crime scene, should they change their booties every time they cross a wall?
From these arguments between experts (the defense, prosecution, and independent experts), there is a strong disagreement over procedures. I see this all the time in every profession.
For example, my son's asthma: 3 different doctors all gave me 3 different protocols to follow. One of these doctors provided a protocol the other doctors believed carried unnecessary risk (the use of oral steroids rather than inhaled steroids for a minor illness). Now the doctor who proscribed the steroids is far more educated than me, but were I to see him again I would inform him that I would not accept this protocol, as I had been convinced by other experts that it was a bad idea. If he had what appeared to be a valid response, I might go back to the other doctors to see what they said... but in this scenario, I would probably just not use the prednisone, and if the doctor pushed me on it, I would switch doctors.
So, yes, from my laymen's perspective reading this material, the crime scene investigators should change their booties when they entered Meredith's room, as well as when they exited it. From the forensic article we read where someone transferred the DNA of a super-shedder and not their own, contamination seems a real possibility, not just a remote one.
The original Massei report, Stefanoni's arguments seemed quite persuasive. My understanding was that the defense said she ignored certain peaks, her response was that the peaks were substantially lower, and it was clear which belonged to the correct profile. Defense said contamination was a real possibility, she explained in clear terms how it was a miniscule possibility.
I tend to view defense experts with skepticality as, in the U.S., they always say what is in the best interests of those who hired them.
This report, however, is by experts that were supposedly independent and approved by both the prosecution and defense (as I understand it). Their response has been aggressive that contamination is a high possibility, not a remote one, and that the peaks which were ignored should objectively have been counted. They say booties should have been changed and evidence promptly but in bags (not passed around).
Now that I have learned that Stefanoni did not provide the TMB results, my perspective of her is of a an "expert with an agenda." This changes the weight with which I accept her opinions. She is an expert FOR the prosecution, not an independent expert. Just as the defense experts opinions were weighted.
That being said, if the prosecutor's experts have a response which provides a coherent explanation for why the evidence should still stand, that addresses the points brought up by the independent experts, I would change my mind.
A totally made-up response that would sway me: the DNA on the bra clasp had 10 peaks, and 9 of them matched Sollecito, a match of 9 narrows it to 1% of the Italian population, is it reasonable to believe that Sollecito is this unlucky? The 10th would exclude him, but if we exclude it we would have to believe that someone who is an almost match to Sollecito touched Meredith's bra. That person is 1% of the population. I guess this brings up a good point, if the DNA is NOT Rudy's, and it is a male's DNA (has a Y), then whose DNA is it? The only person who has any business touching the clasp is her boyfriend.
This would spin me off in a whole new set of questions: If it isn't his then we ARE talking multiple killers. If there are multiple killers is it more likely to be Sollecito rather than a compatriot of Guede? OR we are talking contamination and the DNA comes from someone gathering evidence... as happened to the duct tape in the Anthony trial. And then there is the other DNA on the clasp.. is that DNA a result of contamination? Its peaks are much lower. If there is contamination at that level then are we now saying that contamination definitely WAS present. This evidence magically picked up two other profiles that have no business being there, but did not magically pick up Raffaelle's profile? If low level contamination is a rule, then why accept the knife as evidence?
Is that something that makes sense with DNA testing? I don't know. I would be interested to know how many peaks there were on the bra clasp, how many matched Raffaelle's profile, and how many were dismissed. If all were taken, how many people would that match... of the ones that indicated raffaelle, how many people would that match. How many peaks are tested as well? i.e. They test for 100 peaks, 5 peaks could be anyone, 10 peaks could be 1% of the population 9 peaks 10%, 8 peaks 20%... If my profile is peaks at 1 thru 10, and they get a profile of 1 thru 10, and 20 and 30, is it me? If it is 1 thru 10 and 11-15 is it me?
My impression is that this paper is stating that approaching DNA evidence in this manner is a slippery slope, and while there would be a clear desire to do something like this, it undermines the integrity of the science. It is improper to have the person interpreting the results be an investigator. Instead they should provide the exact results: the profile is not an EXACT match. The investigator then drills down statsticially whether or not the results could still be interpreted as a conviction of this suspect.
