23 research outputs found
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An investigation into the use of CCTV footage to improve likeness in facial composites
Facial composites are an important investigative tool and have been used in numerous high-profile cases (e.g. Yorkshire Ripper). Despite this, a great deal of research has indicated that composites often portray very poor facial resemblance to the suspect/target. While some of the difficulties with the older composite systems (e.g. Photofit and Identikit) were due to system design (see e.g. Ellis, Shepherd & Davies, 1975; Davies, Ellis & Shepherd, 1978; Laughery & Fowler (1980), the hit rate for composites constructed with more modern systems (e.g. E-FIT and PROfit) can still be very low (e.g. Frowd et al. 2005). While research has indicated that composite likeness can be improved at test by combining composites from multiple witnesses (e.g. Bennet, Brace, Pike, & Kemp 1999; Bruce, Ness, Hancock, Newman, & Rarity, 2002; Ness, 2003) research on improving composites during construction has produced mixed results
Improving composite images of faces produced by eyewitnesses
When a witness views a crime, they are often asked to construct a facial likeness, or
composite of the suspect. These composites are then used to stimulate recognition
from someone who is familiar with the suspect. Facial composites are commonly used
in large scale cases e. g. Jill Dando, Yorkshire Ripper, however a great deal of
research has indicated that facial composites perform poorly and often do not portray
an accurate likeness of the suspect. This thesis therefore examined methods of
improving facial composites. In particular, it examined methods of increasing the
likeness portrayed in composites, both during construction and at test.
Experiments 1 to 3 examined the effectiveness of a new three-quarter-view database
in PROfit. Experiment 1 examined whether the presentation of composites in a three-quarter-
view composite will aid construction. Participant-witnesses were exposed to
all views of a target and the results indicated that three-quarter-view composites
performed as well as full-face composites but not better. Experiments 2 and 3 then
examined whether the presentation of two composites (one in a full-face view and the
other in a three-quarter-view) from the same participant-witness would increase
performance above the level observed for a single composite. The results revealed that
two views were better than one. In addition, experiment 3 examined the issue of
encoding specificity and viewpoint dependency in composite construction. All
participant-witnesses were exposed to either one view of a target (full-face or three-quarter)
or all views and they were asked to construct both a full-face and a three-quarter-
view composite. The results indicated that performance was better when all views of a face had been presented. When a target had been seen in a three-quarter-view,
it was better to construct a three-quarter-view composite. However, when a
target had been seen in a full-face view, performance for both full-face and three-quarter
composites was poor.
Experiments 4 to 8 examined whether the presentation of composites from multiple
witnesses would increase performance. The results revealed that morphing composites
from four different witnesses (4-Morphs) resulted in an image that performed as well
as or better than the best single image. Further experimentation attempted to examine
why multiple composites performed well. In particular, it was asked whether multiple
composites performed well because they contained varied information or whether
they performed well because they just contained more information. Multiple
composites from both single and multiple witnesses using the same (PROfit) and
different (PROfit, E-FIT, Sketch, EvoFIT) composite techniques were compared and
the results revealed that multiple composites performed well because they contained
different memorial representations. This combination of different memorial
representations appeared to result in an image that was closer to the ideal, or
prototypical image.
Experiments 9 to 12 examined the relationship between verbal descriptions and
composite quality. The results revealed that there was no clear relationship between
the amount of description provided, the accuracy of the description and performance
of the resulting composite. Further experimentation examined whether the
presentation of a composite and a description would increase performance above the
level observed for a single composite. The results revealed that the combination of a description and a composite from the same participant-witness did increase
performance. This indicated that descriptions and composites might contain differing
amounts and types of featural and configurational information.
Both the theoretical and practical implications of these results are discussed.
Experiments 1, 2 and 3 of this thesis have been submitted for publication. Ness, H.,
Hancock, P. J. B., Bowie, L. and Bruce, V. Are two views better than one? A study
investigating recognition of full-face and three-quarter-view composites. Applied
Cognitive Psychology.
Experiment 4 of this thesis appears in Bruce, V., Ness, H., Hancock, P. J. B.,
Newman, C. and Rarity, J. (2002). Four heads are better than one: combining face
composites results yields improvements in face likeness. Journal of Applied
Psychology. 87 (5), 894-902.
Other Publications
Frowd, C. D., Carson, D., Ness, H., Richardson, J., Morrison, L., McLanaghan, S.,
Hancock, P. J. B. Evaluating Facial Composite Systems. Manuscript accepted for
publication in Psychology, Crime and Law.
Frowd, C. D., Carson, D., Ness, H., McQuiston, D., Richardson, J., Baldwin, H.,
Hancock, P. J. B. Contemporary Composite Techniques: The impact of a forensically relevant
target delay. Manuscript accepted for publication in Legal and
Criminological Psychology
Advances in Facial Composite Technology, Utilizing Holistic Construction, Do Not Lead to an Increase in Eyewitness Misidentifications Compared to Older Feature-Based Systems
An eyewitness can contribute to a police investigation both by creating a composite image of the face of the perpetrator and by attempting to identify them during an identification procedure. This raises the potential issue that creating a composite of a perpetrator might then interfere with the subsequent identification of that perpetrator. Previous research exploring this issue has tended to use older feature-based composite systems, but the introduction of new holistic composite systems is an important development as they were designed to be a better match for human cognition and are likely to interact with memory in a different way. This issue was explored in the current experiment. Participants were randomly assigned to a feature-based composite construction condition (using E-FIT), a holistic-based composite construction condition (using EFIT-V) or a control condition. An ecologically valid delay between seeing a staged crime, creating the composite, and completing the identification task was employed to better match conditions in real investigations. The results showed that neither type of composite construction had an effect on participants’ accuracy on a subsequent identification task. This suggests that facial composite systems, including holistic systems, may not negatively impact subsequent eyewitness identification evidence
Improving composite images of faces produced by eyewitnesses
When a witness views a crime, they are often asked to construct a facial likeness, or composite of the suspect. These composites are then used to stimulate recognition from someone who is familiar with the suspect. Facial composites are commonly used in large scale cases e. g. Jill Dando, Yorkshire Ripper, however a great deal of research has indicated that facial composites perform poorly and often do not portray an accurate likeness of the suspect. This thesis therefore examined methods of improving facial composites. In particular, it examined methods of increasing the likeness portrayed in composites, both during construction and at test. Experiments 1 to 3 examined the effectiveness of a new three-quarter-view database in PROfit. Experiment 1 examined whether the presentation of composites in a three-quarter- view composite will aid construction. Participant-witnesses were exposed to all views of a target and the results indicated that three-quarter-view composites performed as well as full-face composites but not better. Experiments 2 and 3 then examined whether the presentation of two composites (one in a full-face view and the other in a three-quarter-view) from the same participant-witness would increase performance above the level observed for a single composite. The results revealed that two views were better than one. In addition, experiment 3 examined the issue of encoding specificity and viewpoint dependency in composite construction. All participant-witnesses were exposed to either one view of a target (full-face or three-quarter) or all views and they were asked to construct both a full-face and a three-quarter- view composite. The results indicated that performance was better when all views of a face had been presented. When a target had been seen in a three-quarter-view, it was better to construct a three-quarter-view composite. However, when a target had been seen in a full-face view, performance for both full-face and three-quarter composites was poor. Experiments 4 to 8 examined whether the presentation of composites from multiple witnesses would increase performance. The results revealed that morphing composites from four different witnesses (4-Morphs) resulted in an image that performed as well as or better than the best single image. Further experimentation attempted to examine why multiple composites performed well. In particular, it was asked whether multiple composites performed well because they contained varied information or whether they performed well because they just contained more information. Multiple composites from both single and multiple witnesses using the same (PROfit) and different (PROfit, E-FIT, Sketch, EvoFIT) composite techniques were compared and the results revealed that multiple composites performed well because they contained different memorial representations. This combination of different memorial representations appeared to result in an image that was closer to the ideal, or prototypical image. Experiments 9 to 12 examined the relationship between verbal descriptions and composite quality. The results revealed that there was no clear relationship between the amount of description provided, the accuracy of the description and performance of the resulting composite. Further experimentation examined whether the presentation of a composite and a description would increase performance above the level observed for a single composite. The results revealed that the combination of a description and a composite from the same participant-witness did increase performance. This indicated that descriptions and composites might contain differing amounts and types of featural and configurational information. Both the theoretical and practical implications of these results are discussed. Experiments 1, 2 and 3 of this thesis have been submitted for publication. Ness, H., Hancock, P. J. B., Bowie, L. and Bruce, V. Are two views better than one? A study investigating recognition of full-face and three-quarter-view composites. Applied Cognitive Psychology. Experiment 4 of this thesis appears in Bruce, V., Ness, H., Hancock, P. J. B., Newman, C. and Rarity, J. (2002). Four heads are better than one: combining face composites results yields improvements in face likeness. Journal of Applied Psychology. 87 (5), 894-902. Other Publications Frowd, C. D., Carson, D., Ness, H., Richardson, J., Morrison, L., McLanaghan, S., Hancock, P. J. B. Evaluating Facial Composite Systems. Manuscript accepted for publication in Psychology, Crime and Law. Frowd, C. D., Carson, D., Ness, H., McQuiston, D., Richardson, J., Baldwin, H., Hancock, P. J. B. Contemporary Composite Techniques: The impact of a forensically relevant target delay. Manuscript accepted for publication in Legal and Criminological Psychology.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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Eyewitness identification procedures: Do researchers and practitioners share the same goals?
Research has undoubtedly led to a number of important changes to the way police obtain eyewitness identification evidence in a number of countries. However, despite these successes and the significant effort made by researchers to communicate key findings to public agencies, policy-makers and influential law enforcement personnel using a broad range of evidence, relevant policy and practice have either been very slow to respond or have not changed to incorporate the suggestions at all. In this article we employed an online survey to explore the knowledge and opinions of front-line policing practitioners in the UK regarding eyewitness research and practice. This was undertaken to determine how familiar less-senior, operational staff were with key research findings, what their opinions of current practice were and crucially, their views on how identification procedures should be improved compared with the recommendations made by researchers. The results revealed a fundamental mismatch between research and practice, with practitioners indicating a need to increase the rate of positive identifications and research tending to focus on methods of reducing false identifications. This result suggests that an approach driven by the need for the police to produce convictions may be an important factor that is blocking the translation of eyewitness identification research into practice
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Over-observed? What is the quality of CCTV in this new digital legal world?
Poor quality CCTV evidence requires a witness to make an identification of the suspect. Good quality CCTV images are often left to the jury, who are unfamiliar with the face. Psychological research has demonstrated that identification procedures for both known and previously unknown suspects should be very different. A visual comparison of high quality imagery may suggest that a more reliable decision regarding identity will be made. However, studies indicate that when an assailant is unknown, identification is poor even when the image is of high quality, regardless of format. As such, research has demonstrated that recognizing or matching unfamiliar faces even in optimal conditions is an extremely error prone process. This paper examines the current legal framework for identification from imagery in the light of psychological research. Incorrect identifications may not necessarily be safeguarded against in some situations, although further research is needed to elucidate reliable identification methods for criminal prosecutions
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How to develop evidence based practice to support witnesses on the autistic spectrum (ASD) when they give evidence
Current procedures for gathering evidence from witnesses can create significant anxiety to people with Autistic Spectrum Disorders (ASD), due to difficulties with memory, language, social interaction, communication and face recognition. This can impact on the quality of evidence provided. Working with ASD witnesses could also be stressful to police officers, as they are the first to interact with witnesses that could require special assistance, and it is therefore vital for officers to be able to identify and support ASD witnesses. This empirical study aims to address these issues by investigating police officers’ perceptions, knowledge and understanding about ASD individuals as witnesses, as well how this translates into their practice, and is to develop operational procedures to improve policing practice, particularly for eyewitness identification procedures. The project seeks not only to identify areas where improvement might be needed, but also to develop and test procedures which make the most of research evidence based practices
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What’s so ‘super’ about super recognisers?
Super-recognisers are often treated in the face recognition literature as if they are a homogeneous group, whose abilities are analogous and have the same theoretical underpinnings. However, we know that in the normal population there are huge variations in people’s abilities to process faces. For example, while some people display better face matching abilities than face recognition skills, others may show the opposite. Additionally, there are considerable individual differences in people’s ability to process the different types of information contained within a face (e.g. Ness, 2012). For example, while some people are more featural processors (i.e. they rely heavily on processing the individual component features of the face in a relatively piecemeal fashion), others are more configural processors (i.e. they rely more on the spatial relationships between key facial features, processing the face more holistically).
Using tests of face recognition and matching, as well as standardised tasks used to establish featural and configural processing abilities, we investigated how a small group of super-recognisers in the Metropolitan Police varied in their abilities to process faces. The results revealed that super-recognisers are a heterogenous group, with different strengths and weaknesses. We discuss how identifying individuals’ strengths may allow super-recognisers within the police force to be matched up to specific job roles which may be best suited to their capabilities
Are two views better than one? Investigating three-quarter view facial composites
Purpose – The introduction of a three-quarter-view database in the PRO-fit facial-composite system has enabled an investigation into the effects of image view in face construction. The article examines the impact of constructing full-face and three-quarter-view composites under different encoding conditions. It also examines the potential value of three-quarter-view composites that can be generated automatically from a front-view composite. We also investigate whether there is an identification benefit for presenting full-face and three-quarter composites together.
Design/methodology/approach – Three experiments examine the impact of encoding conditions on composite construction and presentation of composites at the evaluation stage.
Findings – The work revealed that while standard full-face composites perform well when all views of the face have been encoded, care should be taken when a person has only seen one view. When a witness has seen a side view of a suspect, a three-quarter-view composite should be constructed. Also, it would be beneficial for a witness to construct two composites of a suspect, one in full-face view and one in a three-quarter-view, particularly when the witness has only encoded one view. No benefit emerged for use of three-quarter-view composites generated automatically.
Research limitations/implications – This is the first study to examine viewpoint in facial composite construction. While a great deal of research has examined viewpoint dependency in face recognition tasks, composite construction is a reconstruction task involving both recall and recognition. The results indicate that there is a viewpoint effect that is similar to that described in the recognition literature. However, more research is needed in this area.
Practical implications – The practical implications of this research are that it is extremely important for facial composite operators in the field (police operators) to know who will make a good likeness of the target. Research such as this which examines real-life issues is incredibly important. This research shows that if a witness has seen all views of a perpetrator’s face then standard composite construction using a full-face view will work well. However, if they have only seen a single view then it will not.
Social implications – There are obvious wider societal implications for any research which deals with eyewitness memory and the potential identification of perpetrators.
Originality/value – No research to date has formally examined the impact of viewpoint in facial-composite construction