Catching More Offenders with EvoFIT Facial Composites: Lab Research and Police Field Trials

Often the only evidence of an offender s identity comes from the memory of an eyewitness For over 12 years we have been developing software called EvoFIT to help eyewitnesses recover their memories of offenders faces to assist police investigations EvoFIT requires eyewitnesses to repeatedly select from arrays of faces with breeding to evolve a face Recently police forces have been formally evaluating EvoFIT in criminal cases The current paper describes four such police audits It is reported that EvoFIT composites directly led to an arrest in 25 4 of cases overall the arrest rate was 38 5 for forces that used a newer less detailed face-recall interview These results are similar to those found in the laboratory using simulated procedures Here we also evaluate the impact of interviewing techniques and outline further work that has improved system performanc

Catching more offenders with EvoFIT facial composites: Lab research and Police field trials.

Often, the only evidence of an offender’s identity comes from the memory of an eyewitness. For over 12 years, we have been developing software called EvoFIT to help eyewitnesses recover their memories of offenders’ faces, to assist police investigations. EvoFIT requires eyewitnesses to repeatedly select from arrays of faces, with ‘breeding’, to ‘evolve’ a face. Recently, police forces have been formally evaluating EvoFIT in criminal cases. The current paper describes four such police audits. It is reported that EvoFIT composites directly led to an arrest in 25.4% of cases overall; the arrest rate was 38.5% for forces that used a newer, less detailed face-recall interview. These results are similar to those found in the laboratory using simulated procedures. Here, we also evaluate the impact of interviewing techniques and outline further work that has improved system performance

EvoFIT facial composite images: a detailed assessment of impact on forensic practitioners, police investigators, victims, witnesses, offenders and the media

This paper assesses use of the EvoFIT facial composite system by police practitioners in the UK and overseas. Results reveal that this forensic system is used extensively: a total of 2,440 times since September 2013. With a suspect identification rate of 60% and a conviction rate of 17%, the impact of this forensic technique is appreciable for helping the police to identify offenders. It was also found that empirically-driven enhancement techniques were used frequently by police practitioners-including use of detailed context reinstatement and holistic techniques during interview, and asking the witness to focus on the eye-region during construction. Research evaluating EvoFIT images published in the media also revealed that composites were produced mostly for serious offences, in particular for sexual crimes. In addition, the vast majority were of male offenders, in their early 30's; victims were female (aged mid 20's to mid 30's); these demographics were similar to composites emerging from another recognition system, EFIT-V / 6. Although this exercise revealed that EvoFIT composites were sometimes published using a more optimal stretched mode, some were presented in a way that did not faithfully represent the constructed image, with the external features cropped. In conclusion, the EvoFIT system is clearly being deployed frequently, with appreciable impact, in the fight against crime

Breath, relax and remember: an investigation into how focused breathing can improve identification of EvoFIT facial composites

Accurate identification of criminal suspects by witnesses is vital for police investigations. Methods such as Cognitive Interviewing techniques have been employed for this reason to enhance witness recall. In the current project, we demonstrate the benefit of including a focused breathing exercise during face construction using the EvoFIT recognition-based facial composite system. Twenty participants, half of whom received the focused breathing instruction, each constructed a facial composite of an unfamiliar face seen the previous day. A further 40 participants attempted to name the resulting composites. A significant increase was found in accurate identification of composites constructed by the focused breathing group

Evaluation of facial composites utilizing the EvoFIT software program

Facial composites are traditionally created with the assistance of a sketch artist, and the resulting image is then circulated in the police force as well as the public community. However, with the advance of computer technologies and a better understanding of how facial composites are created, composite software systems have developed greatly. EvoFIT, an abbreviation for Evolutionary Facial Imaging Technique, is a computer program used to create composites based on the Darwinian concept. It allows a witness to select for global features of the face, that will in turn be combined together to create new faces that have a greater likeness to the offender. The EvoFIT program aims to boost the low recognition values of facial composite methods currently used. The purpose of this study is to evaluate production of two composites from the same person as a mechanism for improving performance. The use of a second composite, paired composites, and morphed composites is examined as mechanisms for boosting recognition. Ten sets of composites representing ten different volunteers (targets) were created using EvoFIT. The first composite in each set was named correctly 8.3% of the time, the second composites at 18.3%, the paired composites at 20%, and the morphed composites at 23.33%. The results support the theory that use of a second composite, a pair of composites, and morphed composites increases the number of instances in which namers correctly identify the target. This research suggests that it is valuable for a witness to construct a second composite using EvoFIT or similar software

EvoFIT composite face construction via practitioner interviewing and a witness-administered protocol

Police require reliable facial-composite systems to help identify, arrest and convict criminals. Recent developments, however, have allowed newer versions of the EvoFIT composite system to be made available for policing. The outcome is an online (cloud-based) version and a new system called Witness At Home, both using a simpler interface. Here, we formally compare these two versions to establish potential benefits to policing. Two experiments were conducted. In Experiment 1, participants observed a target identity for 1 minute and returned 4 hours (Witness At Home) or 24 hours (EvoFIT Online) to construct a composite from memory. No significant difference in composite accuracy was found. In Experiment 2, participants constructed a composite, 24-hours after seeing a target identity, using either EvoFIT Online or Witness At Home. A significant increase in accurate identification was found for EvoFIT Online, with some utility for the self-administered procedure, together indicating benefit for these newer systems plus some areas for development

The importance of detailed context reinstatement for the production of identifiable composite faces from memory

Memory is facilitated by reflecting upon, or revisiting, the environment in which information was encoded. We investigated these “context reinstatement” (CR) techniques to improve the effectiveness of facial composites – visual likenesses of a perpetrator’s face constructed by eyewitnesses. Participant-constructors viewed a face and, after a one-day-delay, revisited (Physical CR) or recalled the environmental context (Mental/Detailed CR) before recalling the face and constructing an EvoFIT or a PRO-fit composite. Detailed CR increased correct naming of ensuing composites, but only when participant-constructors suitably encoded the environment. Detailed CR was also effective when combined with another interviewing technique (Holistic-Cognitive Interview), with focus on a target’s character; it was no more effective prompting constructors to engage in greater environmental recall. Analyses indicate that the Detailed CR advantage was mediated by an increase in face recall. Results are applicable by forensic practitioners to aid eyewitness memory, thereby potentially increasing suspect identification and subsequent arrest rates

The impact of external facial features on the construction of facial composites

Witnesses may construct a composite face of a perpetrator using a computerised interface. Police practitioners guide witnesses through this unusual process, the goal being to produce an identifiable image. However, any changes a perpetrator makes to their external facial-features may interfere with this process. In Experiment 1, participants constructed a composite using a holistic interface one day after target encoding. Target faces were unaltered, or had altered external-features: (i) changed hair, (ii) external-features removed or (iii) naturally-concealed external-features (hair, ears, face-shape occluded by a hooded top). These manipulations produced composites with more error-prone internal-features: participants’ familiar with a target’s unaltered appearance less often provided a correct name. Experiment 2 applied external-feature alterations to composites of unaltered targets; although whole-face composites contained less error-prone internal-features, identification was impaired. Experiment 3 replicated negative effects of changing target hair on construction and tested a practical solution: selectively concealing hair and eyes improved identification

Race and statistics in facial recognition: Producing types, physical attributes, and genealogies

Principal component analysis (PCA) is a common statistical procedure. In forensics, it is used in facial recognition technologies and composite sketching systems. PCA is especially helpful in contexts with high facial diversity, which is often translated as racial diversity. In these settings, researchers use PCA to define a ‘normal face’ and organize the rest of the available facial diversity based on their resemblance to or difference from that norm. In this way, the use of PCA introduces an ‘ontology of the normal’ in which expectations about how a normal face should look are corroborated by statistical calculations of normality. I argue that the use of PCA can lead to a statistical reification of racial stereotypes that informs recognition practices. I discuss current and historical cases in which PCA is used: one of face perception theorization (‘face space theory’) and two of technology development (the ‘eigenfaces’ facial recognition algorithm and the ‘EvoFIT’ composite sketching system). In each, PCA aligns facial normality with racial expectations, and instrumentalizes race in specific ways: as a type, physical attribute, or genealogy. This analysis of PCA does two things. First, it opens the black box of facial recognition to uncover how stereotypes and intuitions about normality become part of theories and technologies of facial recognition. Second, it explains why racial categorizations remain central in contemporary identification technologies and other forensic practices

Varieties of biometric facial techniques for detecting offenders

Many crimes are committed where the only record of the event is in the memory of a witness or victim. Recovering a recognisable image of the offender’s face is then crucial for solving the crime. Traditionally, eyewitnesses describe the offender’s face and select individual facial features – eyes, hair, nose, etc. – to build a ‘composite’. This image is then published in the media so that someone can recognise it and phone the police with a name. Unfortunately, when tested using life-like procedures, this method rarely produces recognisable images. The current paper describes these systems for extracting such biometric information from witnesses. It also describes how useful they are and explores three such approaches for improving their effectiveness. Included are a new method to interview witnesses (a holistic-cognitive interview), a new method to present images to the public (animated composite) and a new system to construct the face (EvoFIT)