Validation, Validation, Validation - what now for forensic R&D?

In the wake of recent court judgements (R-v-Hoey and the subsequent enquiry, followed by the judgement in R-v-Reed) and the publication of the Regulator's draft codes of conduct which attempts to define validation, the issue over whether or not a technique / process has been validated continues to cause utter confusion.

In R-v-Hoey the issue over whether or not the process used by the FSS in dealing with low-template DNA analysis (LCN or "Low Copy Number" as used by the FSS) was scrutinised comprehensively, and challenged by the defence team on the basis that it was not a valid process.

The FSS stated that they had put LCN through their own validation processes including the publication of the method in peer reviewed journals. Furthermore the FSS had been through several rounds of accreditation (inspected by UKAS) during which the process of LCN would have been explored in detail.

The court held that this was not enough and ruled that:

"...However, in the case of LCN there is no validation other than the assertion by Drs Gill and Whitaker that two published journal papers they had written amounted in effect to peer review and thereby the necessary validation, a proposition which was strongly disputed by the Defence experts..."

A government enquiry - held in the aftermath of the judgement held that:

"...we find that the science supporting the delivery of Low Template DNA (LTDNA) analysis is sound and that the three companies (the Forensic Science Service Ltd, LGC Forensics and Orchid Cellmark Ltd) providing this service to the Criminal Justice System have validated their processes in accord with accepted scientific principles using both 28 and 34 PCR cycles for extracts containing less than 200 picograms (pg) of DNA."

In R-v-Reed the court went further and stated that:

"...On the evidence before us, we consider we can express our opinion that it is clear that, on the present state of scientific development:

i) Low Template DNA can be used to obtain profiles capable of reliable interpretation if the quantity of DNA that can be analysed is above the stochastic threshold – that is to say where the profile is unlikely to suffer from stochastic effects (such as allelic drop out mentioned at paragraph 48) which prevent proper interpretation of the alleles.

ii) There is no agreement among scientists as to the precise line where the stochastic threshold should be drawn, but it is between 100 and 200 picograms.

iii) Above that range, the LCN process used by the FSS can produce electrophoretograms which are capable of reliable interpretation. There may, of course, be differences between the experts on the interpretation... However a challenge to the validity of the method of analysing Low Template DNA by the LCN process should no longer be permitted at trials where the quantity of DNA analysed is above the stochastic threshold of 100-200 picograms in the absence of new scientific evidence..."

So at the end of an internal validation by the supplier, several rounds of UKAS accreditation and inspections of the supplier during which the technique was in use, two appeals and a government enquiry, it is the appeal court which drew a line at above 200 picograms here - not the scientists, and not the government.

So how exactly can a method or process used in forensic science be deemed valid? Internal process do not seem to be enough, nor does publication in a peer reviewed journal, nor does an accreditation of the system (of which the process is a part) to a national standard and nor does an independent review of the science by the government suffice. Right now, it is the court that is deciding whether or not a process is valid and furthermore it is defining the analytical levels at which that validity can be challenged.

The regulator demands that providers be accredited to ISO17025 (to be replaced by the forensic standard in due course). Either way, these standards demand validation of processes. UKAS require documented evidence of the technique used in casework so that they can grant accreditation. So in order to bring in new science to forensic science, the supplier must bear the risk of introducing it to casework without it being assessed against the standard in the first place.

Commerical forensic science providers now have to weigh up the probability that their R&D would survive a challenge in court - and if the R&D failed, what the impact on their business might be. It is not just the money that is invested in R&D, it is not just the business that you might win on the basis of the new R&D, it is also the business that might be lost if the court rules against it and/or limits its use or scope. For some suppliers that might be cause enough to close down any R&D programmes that still exist - and who could blame them for that?

Now is not a good time to be doing R&D in forensic science in the UK.