Facial mapping, or facial image comparison, is a term used to describe a process in which an expert will compare an image of an unknown subject to that of a known subject. In the process the expert may have to alter the brightness, compression or sharpness of an image in order to make a more informed decision. Their aim in this endeavour is to ascertain whether the similarities between the two images are great enough to amount to a match.
Facial mapping is perhaps the most commonly used method in the U.K for identifying a subject using imagery. It was first used in 1993 in R v Stockwell and has grown in its use, popularity and reliability in the years since. In 2002, the Attorney General gave the field of expert witnesses in facial mapping further status by stating that “A suitably qualified expert with facial mapping skills can give opinion evidence of identification based on a comparison between images from the scene (whether expertly enhanced or not and a reasonably contemporary photograph of the defendant, provided the images and the photograph are available for the jury)”. Due to its ever-increasing use and prevalence in modern trials, the use of facial image comparison is now considered as a forensic discipline, along with the likes of DNA and fingerprint comparison.
This process understandably involves a degree of subjectivity, in that different experts will have their own methods as there is no uniform method of comparing two facial images. The expert in the case will prove that their process of analysis has followed a reasonable and structured methodology in order to have arrived at their decision. Furthermore, experts are responsible for demonstrating that their method is not only tried and tested but that their opinions are completely impartial and supported by their findings. An expert’s opinion is therefore based upon their personal training, experience and competency in their field.
Due to the nature of the evidence base that facial mapping experts use, they can come across some cosmetic complications when reviewing the footage or image they are examining. Though camera technology has improved greatly over the last few decades, not all footage that the experts deal with will be of the highest standard. There may, for example, be poor lighting or a low resolution on the footage. Furthermore, due to compression the subject’s face and defining features may be somewhat difficult to make out. Another key problem is the angle of the footage, as CCTV is almost always from an elevated angle it offers a very different angle of the subject than in a face-on mug shot. Though these cosmetic problems can cause issues for the facial mappers, they also necessitate their role in court, as experts are well equipped to find the merit in otherwise inconclusive footage.
Through image enhancement, revision and comparison an expert witness facial mapper can add compelling evidence in a courtroom and give a great deal of weight to a case. Though there are some limitations to their work in certain cases, their role in the courtroom continues to become more established and crucial. Indeed, the ability of a facial mapper to get the most out of an otherwise inconclusive piece of evidence is unrivalled by any other. Within 24 hours of your enquiry your dedicated case manager will send you a portfolio of CVs containing our expert witness profiles. Our expert witnesses, across all of our fields, are hand-selected and court-ready, with all the tools and experience to help with your case.