VALIDATE: “to make something legally acceptable”; “to prove that something is correct”[1]
That seems clear enough then. You may think that if you were proposing to use something in court then you would not only expect to, but want to, show that your evidence was validated. Weirdly, that does not appear to be the view of the Scottish Police Authority, and they are prepared to spend public money to go to court to avoid proving the validation of their evidence.
Recent years have seen advances in forensic DNA profiling to the extent that we are now frequently dealing with microscopic, invisible biological material mixed together which produces a complex mixture of DNA types. This creates a nightmare for the scientist attempting to assess the actual contributors to the sample. Computer programmes have been developed which claim to do the job. These ‘probabilistic genotyping’ systems generally work by taking hundreds of thousands of guesses at the possible contributors to the DNA profile to see if any fit the crime profile. One of these systems is called STRmix.
STRmix is a commercial product which has been bought by the SPA. Before it can be used in a laboratory it must be validated within that laboratory. We have been engaged on behalf of a person charged with a crime. Part of the evidence against him is a statistic calculated by the STRmix software. We sought disclosure of the validation supposedly undertaken by the SPA prior to it being used in real casework.
The SPA, a publicly funded body, has not only refused to provide the defence with this vital information, it is understood that they now intend to spend public money on their own Counsel to go to court to block such disclosure.
In whose interest can it be to keep the validation secret?
What is within the data that the defence should not see?
Why is public money being spent to avoid scrutiny of a public body which is supposedly serving the public?
This is of course not the beginning of the secretive and obstructive approach by the SPA, who have a long history of failing to disclose to the defence what is disclosed in other civilised jurisdictions. For more on this click here
September 2018