Having completed thousands of criminal cases in several countries, inevitably we come across many interesting matters arising from some of those cases. These 'Matters Arising' may be of interest to the wider forensic, scientific, legal, and indeed general community. We provide them to further the cause of 'better science, better justice'.
Naturally, we see only a tiny proportion of the cases that may provide important learning points, so if you have a case that you think provides and interesting Matter Arising, please email us via our contact page and we will consider presenting it on these pages.
Outsourcing by the Scottish Police Authority
We were alerted to the fact that the SPA were outsourcing DNA casework to commercial suppliers in England when we received the ‘branded’ statements from the scientists involved. But here’s the twist; for these cases we were provided with the English commercial laboratory casefiles as requested, disclosure deprived to us when the work is done in the publicly owned SPA laboratory!
Contamination being hidden; unacceptable
Labs frequently check that DNA samples have not been contaminated by police or lab staff. If the samples are contaminated then they should be discarded, not introduced as evidence.
In a case involving the finding of DNA on a weapon, the lab discovered the DNA from one of the police staff on a key sample. This is troublesome in itself, but even more troubling are the facts that this was not mentioned in the scientist’s statement or provided to us in the lab casefile.
In many cases, the best that can be said is that it is not possible to identify anyone. In this case, we were able to exclude the defendant on the basis of one moment from the CCTV recording.
Confusion in Court on LCN/LTDNA profiles
The potential for misunderstanding of one Court following the judgment of another without the full knowledge of the facts and nuances that led to the published judgment are evidenced between the cases of Reed & Garmson in the Appeal Court in England and Wales, and the case of Wallace in New Zealand. This article illustrates how confusion has arisen and clarifies the issue with respect to Low Template (LTDNA) or Low Copy Number (LCN) DNA profiles.
DNA and 'Expert systems'
Recent trials involving LCN or Low Template DNA in which we have been involved have seen the introduction of statistics using complex and not widely accepted computer programmes to produce statistics for profiles that the DNA expert has been unable to calculate using conventional methods. The interpretation of such profiles remains controversial with various approaches being proposed.