Forensic science in cases is an interpretative exercise; it may not provide definitive evidence. That interpretation depends upon the specifics of the case.
Forensic science is continuing to make technical advances. In one of the most widely used techniques DNA profiles can now be generated from something you have touched. The question is was the contact innocent or part of a criminal event? New fields are emerging. In the last few years we have seen the development of forensic techniques involving mobile telephones. Each time you make a call from or to a mobile phone, the unique number of the mast through which the connection is made is recorded. This data can be analysed and tested to determine the vicinity from where the call was made.
Companies like Keith Borer Consultants are involved in cases in a variety of different roles:
- Check of prosecution evidence – has the work been done correctly?
- Undertake further testing from case samples to corroborate or otherwise the prosecution work.
- Re-evaluate the significance of the evidence in relation to the information provided. Scientists on either side will usually have only part of the information about the circumstances of a case. In a recent courtroom discussion of secondary transfer of DNA (that is from one person to another via a third party or object) the prosecution scientist was unaware that the defendant had previously lived in a particular house and was a regular visitor there. Without our enquiries, the jury would not have been in a position to assess the opportunity for a secondary transfer explanation relative to the situation if the defendant had never been to the property in question.
- Expand the forensic investigation beyond the work that has been undertaken by the prosecution. All forensic investigations are rightly subject to budgetary pressures. Selection is a necessary process and not everything can be looked at. An aspect which could be vital in the defendant’s account may be neutral in preparing the case for the prosecution. For example, in England & Wales we are increasingly seeing in kicking assaults that the shoes have been examined but not the trousers. The latter may provide further information helpful to the interpretation. Similarly in a case relying on a rape victim’s DNA profile generated from staining on bed linen, our examination of the defendant’s mattress revealed numerous stains supporting the defendant’s account that there had been a sexual relationship between the parties for some time.
- Advise on the limitations of the forensic evidence. We are often asked to comment on the absence of scientific findings. If there are no scientific findings, does this mean the defendant was not present? This is not necessarily the case. Take the example of a shop window being broken by a brick in a matter of criminal damage. No glass fragments were found on the clothing of the defendant who was arrested by the police a short time after the incident. No glass fragments – the wrong person? Not in this case as the defendant had thrown his missile from behind a half height wall which had shielded him from the glass fragments. Without the wall, the conclusion from the scientific evidence would have been completely different.
Our work ensures that in the Court room there is balance in the interpretation of the scientific evidence on both sides. Furthermore, high quality forensic work on behalf of the defence can shorten the legal process. It is often a valuable exercise for scientific experts to meet before the trial. This can enable missing information issues to be ironed out and for points of agreement and difference to be identified.These can then be presented to the jury in much more coherent and efficient process.
Dr L Jane Bloor, Director
This article has been revisited in 2018 by Senior Manager, Dr David Schudel. See HERE.