Expert Witness featured the following article by Jo Millington on Streamlined Forensic Reports (SFR) and their use in the Criminal Justice System.
If you are representing an individual in which only SFR reports have been disclosed, please ask us about our SFR Advisory Service. We will help you identify the strengths and limitations of early scientific evidence so that you can submit a challenge if necessary.
Streamlined Forensic Reports (SFR)
There is increasing pressure across the Criminal Justice System to deliver forensic science more quickly and for less money. The faster/cheaper philosophy is epitomised in the Streamlined Forensic Reporting process. This approach was introduced by the CPS to ‘reduce unnecessary costs, bureaucracy and delays in the criminal justice system’, and ‘to ensure that the key forensic evidence that the prosecution intend to rely on is presented in the shortest and clearest way so as to achieve early agreement on forensic issues and to identify contested issues’. It is implied that the SFR ‘report’ will outline the scientific evidence in such a way that the reader will understand the strengths and limitations of the scientific findings in context of their case, and that it will be upgraded into a court report, which addresses the key issues and satisfies the Criminal Procedures Rules, as and when necessary. Yet, on a regular basis, forensic experts instructed by the Defence are being faced with reports where the scientific evidence has only been conveyed in an abbreviated form, with no opinion from a Crown scientist regarding what the findings could mean in the context of the case circumstances. This introduces risk into the Criminal Justice System.
As an example, the ‘DNA Stage 1 SFR’ typically outlines the DNA match that exists between a crime sample and a named individual. That individual might then be asked to explain how ‘their’ DNA came to be present at that crime scene. Whether this is a reasonable question is best considered in the context of whether you feel that you could readily explain where your DNA might be. Not great lumps of your DNA, minute traces that you may have left purposefully or unintentionally on things, and including DNA that may have been further transferred by others, without your knowledge.
We recently published a Short Guide to Forensic DNA Reports, which outlines the questions that you should ask when presented with a DNA SFR:
DOES THE SFR TELL YOU WHAT THE DNA CAME FROM? Has the DNA been attributed to a biological material?
If a DNA profile can be confidently linked to a body fluid, it is 'easier' for the scientist to address issues such as 'how the DNA might have been deposited'. For example, if the DNA can be attributed to blood, we can talk about how that blood might have been deposited on an item, by looking at the pattern of bloodstains. If the report does not contain a clear opinion regarding the biological source of DNA, including if it's not possible to say, no scientist can provide definitive interpretations as to how the DNA could have got there.
HAS AN EVALUATION BEEN DONE? Have the DNA findings been put into context?
A DNA profile on its own, or a 'DNA match', does not tell you how, what, where or why. It is important that the DNA findings have been evaluated in light of the case circumstances. This includes scenarios provided by the Prosecution and the Defence. If the DNA findings have not been fully evaluated in context, their significance could be misconstrued and the DNA match overstated.
If the DNA report includes phrases such as 'one explanation for the DNA findings could be that Mr X handled the knife’, it follows that there could be other, legitimate, explanations. If an account from the defendant was not available when the scientist wrote their report, they may say: 'if an alternative explanation is provided, I can evaluate the findings further'. If this hasn't happened before trial, it must be done. Further evaluation could potentially neutralise the evidence, depending on the case circumstances.
IS THE DNA MIXED WITH OTHER DNA? Has a DNA mixture been obtained?
When multiple people have contributed DNA to a sample, a mixed DNA profile will be produced. The DNA result itself does not tell us when, or in what order each part of the DNA was deposited; or how long it has been on an item. It also can't tell us where the DNA was located originally, which is relevant if material from different areas has been combined into one sample.
A variety of computer programmes are now used routinely to resolve complex DNA mixtures, but again, the result of any statistical calculation does not tell us how or when the DNA was deposited.
If it is suggested that someone could have contributed DNA to a sample, the finding must be subjected to some form of statistical assessment before it can be considered evidentially. If a statistical assessment has not been done, you must insist that it is.
DNA STATISTICS. Has an evidential strength of support been assigned to the DNA findings?
If a DNA profile is suitable for a statistical evaluation (using standard or specialist methods) the DNA match will be conveyed as a number. A billion is commonly encountered. This number does not tell us how or when the DNA was transferred, or how likely it is that someone 'did' a particular activity. The assessment of whether an individual may have been involved in an activity, such as kicking, punching or handling must be considered independently. The scientific or evidential strength of support given to activity-level propositions is calculated in a different way to the DNA match probability. Scientists may draw on their experience, but their opinion must be evidence-based and take into account case information and relevant data from transfer & persistence studies. Forensic science cannot answer questions such as whether an individual committed an offence, this is a matter for the court.
In our experience the potential impact of the scientific findings in an investigation, a DNA result for example, can change significantly depending when the evidence has been introduced into the criminal justice process, and the format of the report. As a general rule our advice would be that unless the DNA findings in your case have been specifically evaluated in light of the case circumstances, including scenarios presented by the Prosecution and Defence, their potential evidential significance should be considered as undefined.
If you are dealing with a case in which these factors apply, please give us a call. We always offer free advice and we are able to provide quotes for Legal Aid purposes if necessary. We have been working in the arena of forensic evaluation, including DNA and body fluid interpretation, for over 75 years, and we can help you put the science into context.