Facial Mapping is the objective comparison of questioned facial images with known reference imagery, in order to determine whether the two faces under comparison may be excluded from being the same person, and if not, the likelihood of them being the same person.
Tests used include a proportional comparison (where appropriate), morphological comparison, and superimposition.
It is unusual for such an exercise to result in a conclusive identification, although exclusions are quite possible, with the image quality of the questioned person being critical to the outcome.
An assessment of the questioned image quality is a vital part of the process, which allows the correct qualification of any perceived similarities or differences. Therefore, the process of facial mapping may be used as a means of illustrating the limitations of any identification evidence forming part of a case.
The quality and suitability of the reference (known) imagery is important in ensuring the most robust and reliable results, in particular viewpoint (angle of view) and camera-to-subject distance, and such photographs may be taken under our guidance, or for best results we can take the comparative photographs.
In order to provide the most reliable results and to maximise the chances of the identification of significant differences (should they exist) we will routinely include the examination of any useful physiological features, including overall build, physical proportions and posture.
Facial mapping expertise is achieved through experience and can be measured by the acceptance of reports presented in the court. Rob Butler, our Facial Mapping Expert, has given evidence on hundreds of occasions at many dozens of Crown, Magistrates’, Coroners’ and Youth Courts throughout England and Wales, including many occasions at the “Old Bailey” (Central Criminal Court), and also courts in Scotland and the Channel Islands.
Why have this evidence checked?
Mistakes have been made regarding identification evidence from CCTV, both by lay-witnesses and experts.