Before CCTV systems were conceived, eye-witness accounts were the only method of identifying a suspect based on their facial features. The pitfalls of this type of identification have been well documented numerous times with regard to the brain’s ability to both forget and modify what a person thinks they witnessed, due to the stress of the situation. It is not surprising therefore that estimations put this method of identification as the greatest factor in wrongful conviction proven by DNA testing.
Facial Comparison, also known as facial mapping, is a field that has seen increased prevalence over the last 20 years due to the proliferation of CCTV cameras in our towns and cities. It has the advantage of not being compromised by stress and the possibility of limiting biases as far as possible. The basic premise is to compare the face of a suspect from a CCTV recording with the face of an individual from a high-quality reference photo (such as a mugshot), to determine the possibility of them being the same person.