Excellent little interview here:
http://www.nature.com/news/forensics-specialist-discusses-a-discipline-in-crisis-1.16870
...with Niamh Nic Daéid of the University of Dundee, UK.
Following on from Diocletus introduction of the Mark Dwyer decision in New York, it seems that the good judge has sent out some international shockwaves.
"So the courts just don't trust some of these forensic techniques?
I think that’s increasingly occurring. For example, in the United States a judge [Mark Dwyer] refused the admission of DNA evidence in his courtroom because of the current debate in the forensic-science literature. That’s really worrying."
It ought to be abundantly clear to any jurist with a degree of scientific understanding that LCN DNA typing is -
by its very nature - a tool that should be used only with extreme caution.
It should be abundantly clear because the very rationale for low-template analysis - i.e. the attempt to generate DNA profiles where only minuscule amounts of DNA are available - presents self-evident problems. The four most important and relevant problems are these:
1) Contamination at every level of the process (collection of evidence, storage and transportation of evidence, testing of evidence). At these tiny levels, even airborne DNA contamination is a potential problem. And certainly tertiary touch contamination and machine contamination are possibilities.
2) Amplification of noise which is subsequently misinterpreted.
3) Misinterpretation of EDFs and electropherograms - including improper, subjective, suspect-centric interpretations.
4) Lack of repeatability of amplifications and testing, owing to the tiny amounts. This causes very real problems relating to confirmation and validation of the test outputs and their interpretations.
For these reasons (and others), the
very minimum requirement is that any low-template evidence is collected, transported and stored in ultra-sterile conditions, and that it is then tested under extremely stringent protocols (including positive pressure hoods to exclude airborne lab contamination, and incredibly thorough (including UV) cleaning of all surfaces, machines and tools in the lab). Even then, the inherent imprecision attached to low-template work may still mean that it still does not qualify as probative evidence in a criminal justice environment.
Of course, it goes without saying that not-a-real-doctor Stefanoni and her band of goons fell at pretty much every single hurdle when it came to low-template work in the Kercher case. Every sane, non-partisan DNA expert in the World would readily state that the LCN evidence in the Kercher case was totally worthless and unreliable.
