The detective leading the search was briefed on the size of the knife used to kill Mez. It's called 'communication.'
Actually he specifically testified he had not been briefed on the size of knife to look for.
"MAORI – You said: I took this knife because according to my police intuition this knife was compatible with the wounds that I never saw. What do you mean?
FINZI– I mean, I never saw the wounds, but the morning after the murder during some breefings I was told by our senior managers how Meredith had died.
MAORI – And what did they tell you about Meredith’s death? Please share...
FINZI – They said she had been stabbed in her throat with many knife thrusts. MAORI – How many wounds?
FINZI – I don’t know; many...
MAORI – What was their shape?
FINZI – I don’t k now. They were deep, I’m reporting to you what other persons reported to me
MAORI – What was their depth?
FINZI – I don’t know, I never measured them.
MAORI – So, during the perquisition of Sollecito’s apartment, you just knew Meredith had been stabbed with a number of knife thrusts... where?
FINZI – in her neck, and throat.
MAORI – And you were unaware of the width and depth of the wounds.
FINZI – Yes, certainly.
MAORI – So, you did not know the length of the blade...
FINZI - If someone tells me the wounds are very deep, then I suppose...and wide, I suppose the blade, surely, but it may be a big blade.
MAORI – OK, and a while ago – in answering a question of the prosecutor – you said there were other knives in Sollecito’s apartment; some of them were smaller, and some of them were bigger than this one.
FINZI – Yes
MAORI – But you didn’t focuse attention on the bigger ones. Why ?
FINZI – Because in my opinion they were of no interest.
MAORI – You say “ in my opinion “ ...so it was a mere opinion.
FINZI – It was an opinion.
MAORI – A mere opinion or a scientific evaluation? Maybe you knew the shape of the wounds, and therefore...
FINZI - No, no, I say again , I never saw Meredith’s wounds, people had reported to me ...so in my opinion that knife could be...its blade might be compatible with the wounds, it might be...
MAORI – The first knife you see...
FINZI – yes, because it stood on the cutlery."
He just took the first big knife he saw. Not with any guidance on the size of wounds. Indeed it subsequently became clear that some of the wounds were incompatible with this knife so another knife had to be introduced to the scenario. Quite apart from the bloody imprint showing a knife compatible with all the wounds but not with Sollecito's knife.
One would have thought a proper investigation would collect all knives able to inflict stab wounds and test them.
A popular PIP misrepresentation. The knife had to be at least 9cm to have breached the hyoid bone. The bruising around the wound were elegantly shown by a forensic pathologist to be the same curved moon shape of a thumb nail, and was proportional to the other finger mark bruises found around Mez' lower face and nostrils.
The problem is there are three wounds all 8cm in depth. Easy to explain with an 8cm blade up to the hilt difficult with a longer blade. I'll agree to a disagreement by the forensic specialists about the cause of the bruising whether due to a hilt or not.
It came back as low copy number (LCN) - probably thanks to vigorous scrubbing of the knife - Stefanoni found that when she amplified the LCN sample enough times (i.e., a chemical reaction which causes the DNA string to replicate itself over and over again, a well-established and weel-used technique in the medical world of research, [e.g., cancer research]) the machine showed a DNA reading of the loci as billions to one against it was anyone's other than Mez. This reading is done by a machine and cannot be faked. Raff's expert forensic defense representative was there as a witness and did not complain of any issues. All parties agree it is indeed Mez' DNA.
The DNA typing result - EPG - is probably that of the victim. That is to say that the sample put into the machine contained some of the victims DNA. That is not to say that DNA originated from the knife, nor that if it was on the knife it was attributable to the murder. The negative controls from the concentration and amplification process have not been revealed. The knife was not handled in a way appropriate for LCN DNA analysis. Knox's DNA was on the handle, but this certainly does not mean she used the knife for a murder. If the knife is thought to have been so thoroughly cleaned that no trace of blood and only the slightest trace of DNA of the victim is left then that cleaning would certainly have removed any trace of the wielder.
Mez is not of 'the human species'? Obviously, it will be body tissue in the form of skin, fat layers and other tissue. Blood is not the only source of DNA. Blood washes off easily if rinsed straight away. Stefanoni assess initially that the blood drips in the bathroom were compatible with pure blood (cotton bud box) and more and more diluted blood as it got to the sink and bidet. Mixed Amanda and Mez DNA. This is a scientific fact.
To correct Welshman, in fact the sample from the knife blade was quantified (contrary to what Steffanoni falsely testified to the court), using a non species specific technique. No DNA human or otherwise was detected. There is something odd about why this sample was typed when other samples with no detectable DNA.
Could you link to where Steffanoni reports on dilution of blood (and how she does so).
Both merits courts found it a fact there was no contamination.
The problem is they are then left with explaining the DNA off other persons, if they do not believe contamination occurs then they must believe these are other participants on the crime.
The problem is since the laboratory did not meet the standards to do LCN work contamination is likely. The way one tries to avoid this is by running duplicate samples not something Steffanoni did.It obviously did, as Mez' DNA showed up.