Ok, so this is very close to an answer. If she is routinely "sloppy", and knows she can get 'findings' that occasionally show up that are favorable to the prosecution, does she know before she starts testing the knife, that she can "find" meredith's DNA, if she tries hard enough?
(Especially given the fact that Meredith's DNA had been tested in the lab on the same equipment, in quantity at some point previously. Exposure to open air? Residue in the machine that becomes readable by amping up the noise?)
Or does she think if she runs enough samples, in small enough (i.e. unreliable) quantity, in non-repeatable (by destroying evidence) and non-verifable testing (by hiding data), she has a good shot at achieving that 'finding' AND depriving the defense of any opportunity to dispute it?
It seems to me, that her having constructive knowledge that the target DNA is, or has been recently, physically present in the lab, then she's effectively cheating by specifically looking for a residual trace contamination, and claiming its a 'finding' of legitimate analysis.
Is having a "good shot" at finding the result she needs by playing up to and beyond the edge of reliability, enough certainty for the police to believe they can pick out any knife at random, and, "it will do"?
Do the police believe Stefanoni can 'probably find a DNA match', or certainly will find a match?
Knowing the order of testing samples, how close are they to having tested Meredith's DNA is relevant, no? If it's closer in time, and they know it AND conceal it, doesn't that suggest they are 'playing' with contamination and full well know it?
There's not much of a difference between 'good shot' and a 'sure thing', but look at the timing. Wasn't it the day after Raf's family disproved the shoe print was Raf's, that Stefanoni came up with these 2 crucial DNA matches?
It's a small difference, but still a difference. I'm starting to lean to the 'good shot' camp', though I was probably a 'sure thing' when I started writing this post. On balance, I don't think she's competent or ethical. So a 'sure thing' doesn't seem to fit her vocabulary, because everything she does is half-way. If it's just a 'good shot' combined with the ability to hide the data and destroy the sample so no re-testing, well that's a strategy.
Maybe the most interesting question is the mindset. What does she think she's doing? Good science, Good police work, or Good framing?
I continue to think well of Stefanoni (in that I think she was not deliberately fixing results). I think she really did not think there was a contamination issue. I think that what she had noticed is that if you run lots of samples at LCN eventually you get a result. I think that occasionally she got favourable results; if you are only analysing incriminating samples then so long as one turns up that is fine. Just think of the other samples, if MK DNA had turned up on the Luminol positive samples from Sollecito's flat, or his boxer's or his shoes it would have been just as bad.
I blame the director of the lab whose responsibility it was to ensure proper protocols were in place, and below him the QA manager, (although I suspect there was no QA manager, which illustrates why there should have been one).
I think it is cheating but it is deniable including to oneself. I suspect record keeping was just sloppy they only kept results they thought were significant.
