I didn't dream your DNA mix-up, y'all mixed up smear (which is chaos) with contamination (which is a rare constructed occurrence).
If Peter Gill lectures all the DNA specialists that came before him on Meredith's case like they're 6 year olds who don't know:
1-What a DNA trace is and how to interpret it as signal/noise
2-How a judge can use a DNA expert and build his case
Then no one should be embarrassed pointing at Peter Gill's simple mistake:
We don't live through our day leaving a trail of DNA.
DNA is produced on impact. Namely all denaturation processes: heat, friction, stress, acid, etc.
RS came in significant collision with Meredith's bra.
Please give it some consideration, Peter Gill is mistaken.
I think you have your own unique terminology that is hard for others to comprehend. Smear is not an often used term in DNA, it might help if you defined your terms.
I do not mean to be condescending, but it may be worth considering the history of forensic DNA. Originally the DNA was testing a known sample with intrinsic meaning. So you have a rape murder, a semen sample is found. There is not much doubt about what the donor of that semen was doing, nor when. The semen is typed then it can be compared to suspects. To begin with one needed around 2 square cm of blood stain to extract a DNA profile. Contamination was less of an issue because so much DNA was needed to type and the source of the DNA was overt. As extraction methods improved, and sensitivity of typing methods improved the DNA became divorced from its source. This is what is termed trace DNA. DNA with no clear origin. One cannot tell if the DNA originated from snot, pee, tears, blood.
So you have low transcript number DNA a few cells worth. Perhaps you find the DNA in a bomb. The prosecution argue that the DNA must have originated from the bomb maker. But the courts ruled that DNA typing of this type was qualitatively different from e.g. the DNA typing of a blood stain. Strenuous precautions needed to be taken to ensure that the sole source of the DNA was the thing being tested. This issue was recognised from the very first time LCN DNA trace typing was presented as evidence in court.
There are no distinguishing features of DNA trace that determines whether it was deposited by primary, secondary or tertiary plus transfer. It has been shown that if say person A shakes hands with person B, then person B handles e.g. a glass more DNA of person A can be deposited than of person B who actually handles the glass. What a few years ago was undetectable or a partial match could be retested now and give a full profile. Guilty people can deposit partial profiles and innocent people full profiles.
An honest statement about the DNA on the bra hook (assuming that the DNA was there in the first place and it was not in laboratory contamination) is
1) It is not known when it was deposited. A reasonable time frame is between the last wash (and there is some evidence for DNA transfer during washing of clothes), and the bra hook collection.
2) It is not known the source of the DNA. It might be from a sneeze or sweat or skin cells.
3) It is not known whether the DNA was deposited by direct contact with Sollecito, or indirect - secondary or greater transfer.
The prosecution need to make a case that the DNA transfer occurred during the crime. The defence need to argue the converse. It is not reasonable for the prosecution to be given a pass on this, but the defence be made to prove a route of transfer.
