Police use composites to identify potential suspects, usually in cases of serious crime (e.g., those involving rape, murder and aggravated burglary), and so maximising the effectiveness of composite images from this form of forensic evidence is of importance both in terms of best use of police resources and correct identification of offenders. The project focuses on methods for evolving the most identifiable likeness of a face, looking specifically at what is referred to as ‘population size’. In this case, how many faces should witnesses be shown for selecting best matches (of a target face), whether more examples would be preferable in the first or second pass (‘generation’) through the system, the importance of facial shape and texture information, and the optimal evolving procedure to use based on strength of memory.
Carefully designed experiments are exploring the best evolving strategies to use, based on the tried-and-tested “replication and extension” model. When assessed using procedures designed to mirror real life use of composites, including construction of an unfamiliar face seen the previous day, initial results indicate that a smaller population size is more effective in general than a larger one, to promote more identifiable faces. This finding is currently being assessed by forensic practitioners of the EvoFIT system in the UK and abroad.
Members:
Project lead: Dr Beth Richardson
Project staff: Elizabeth Jackson
Collaborators and partners: Professor Charlie Frowd, Dr Cristina Fodarella
Related research projects
Investigating the effect of visual load on EvoFIT facial composites
The research programme is investigating the impact of presentation of faces to eyewitnesses during construction of EvoFIT facial composites.- Article
Helping the police to identify offenders using EvoFIT facial composites
In the fight against serious crime police forces worldwide are using advanced digital technology co-developed with the University’s forensic practitioners. Enhancing the effectiveness of facial-composite images
The aim of this programme of research is to understand how to produce more identifiable facial composites by enhancing internal facial features (i.e., the eyes, mouth) using a holistic composite system.Self-administered procedures for constructing identifiable facial composites
Our research focuses on techniques that allow police to identity suspects through use of composite images produced by witnesses and victims of crime.Using detailed environmental recall to enhance facial-composite images
The programme of research aims to improve the effectiveness of facial composites by recalling the environment in which a face was seen, which allows a witness to construct the face of an offender more effectively.
