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‘Analysis’ is the first stage carried out by a fingerprint examiner when comparing two fingerprints using ACE-V methodology (SWGFAST, 2011). Analysis establishes the suitability of a fingermark for further comparison by identifying the fingerprint characteristics present (SWGFAST, ibid). A study of the analysis stage found participants who had been trained in the ACE-V process able to identify more fingerprint characteristics with less intra-variability in the characteristics found than those who had not been given training (Schiffer & Champod, 2007), highlighting the difference in analysis ability between experts and novices.

Psychological studies have consistently supported the idea that a higher cognitive ability leads to higher performance in tasks (Beier & Oswald, 2012) although, there have been a number of studies that suggest that higher cognitive ability may actually be a hindrance when carrying out certain tasks (Gimming et al., 2006; Bielock & DeCaro, 2007). Ways in which experts excel and are hindered have been summarised by Chi (2006) who states that experts excel at detection and recognition of patterns but that they can be overconfident and vulnerable to bias. Dror (2012) has applied this idea to the domain of fingerprint examination, stating that expert status leads to an increased vulnerability to

Page | 34 bias, and focussing his research in the area to application to experts, only using novices as a point of comparison. This is problematic as there are decisions being made within the field of fingerprint evidence by ‘novices’. Latent fingermarks are chemically developed by fingerprint practitioners in a laboratory, and these practitioners must then decide whether or not the fingermark is of sufficient quality to be forwarded to a fingerprint examiner who will carry out the ACE-V process (Expert Working Group on Human Factors in Latent Print Analysis, 2012). In making this decision the practitioner is, essentially, carrying out the analysis stage of the ACE-V process but without the training that qualifies them to be an examiner, or provides expertise in this analysis process. This novice decision (relative to the analysis of the examiner) is, arguably, the most important decision in the chain of evidence as any fingerprints which are excluded at this stage will be lost. A poor decision will either lead to a waste of resources through an examiner being required to consider a fingerprint of too poor a quality, or lead to a loss of evidence.

2.6.1. Potential differences in fingermark sufficiency decision making between practitioners

and examiners

Fingerprint sufficiency has been the subject of research, but this has focussed on the value assessment made by fingerprint examiners to determine whether or not to continue with a comparison. A study by Ulery et al. (2013) attempted to understand the basis for this sufficiency decision through modelling the relationships between the value determinations and annotations made by fingerprint examiners in the US. Ulery et al. (ibid) note that this process is a subjective one, with no formal criteria, which relies on knowledge and experience as opposed to a quantitative threshold. However, they found fingerprint minutiae count to be the most significant factor when determining the value of a fingerprint. Other factors were identified as the clarity of the print, the types of features present, the quantity of useable print and the relationships of the features present (Ulery et al., ibid). There is debate about the use of numerical standards by fingerprint experts throughout the ACE-V process (Evett & Williams, 1996), with the UK no longer utilising a 16-point standard for a fingerprint match (Mackenzie, 2011). The finding by Ulery et al. (ibid) that a numerical threshold is, in practice, being used at the analysis stage may mean that there are potential inconsistencies between the decision- making capabilities of ‘experts’ (examiners) and ‘novices’ (practitioners). Langenburg (2004) found that the number of fingerprint minutiae identified by examiners was higher than that identified by lay persons, supporting the idea that experts excel at the detection and recognition of patterns (Chi, 2006, Schiffer and Champod, 2007). This may suggest that, given the same fingerprint, a fingerprint development practitioner, who has not been trained as an examiner will see less minutiae that the fingerprint examiner who has undergone comprehensive training in the ACE-V process. This demonstrates the importance of the threshold at which a development officer decides to forward a

Page | 35 fingermark to an examiner, which should allow for these potential differences in pattern recognition ability.

The potential problem of differing training and expertise between examiners and practitioners is vulnerable to exaggeration by a relative absence of communication between the two domains and a lack of a joined up approach to working. This is a problem that exists at both a national and a local level in the UK. As previously described there is no national formal forum for communication between the laboratories and bureaux, and laboratories are not represented at either the Fingerprint Quality Standards Working Group or the Fingerprint Strategic Network (Stow, 2014). This means that key stakeholders within fingerprint development are not necessarily kept up to date with changes in bureaux policy and procedure, and are not represented in discussion or consultation. It would seem to be the case that the policies, procedures and working practices of the bureau are essential knowledge in order to ensure that the end product of the laboratory, the submitted fingermark, is suitable for the requirements of the customer, the bureau. Equally there is often a lack of communication on a local level, within individual Scientific Support Units, which may result in a lack of knowledge of expectations of the customer, in particular if new techniques for uploading fingermarks to the AFIS system, or image transfer are employed, or if new methods of reporting are introduced. Such changes on a local level may alter the requirements for fingermark images to the bureaux potential altering the threshold at which a mark may be deemed useable. Without communication of changes such as these it may be difficult for practitioners to submit fingermarks at an appropriate level.

A further exaggeration of the potential differences between practitioners and examiners may result from the external methods of training procured by the majority of UK police forces. Practitioners attending the College of Policing Fingerprint Laboratory Officer course will learn a standardised approach to fingerprint development with a limited focus on mark submission which uses standards set by the College of Policing for the purposes of the assessment (Lagden, 2014). Unless the requirement of the practitioner’s own bureaux is well enforced and additional training is given to assert these standards, practitioners will be working to a different threshold to that of the examiners that they are working with. This initial training, which instructs practitioners to submit all pieces of fingerprint ridge detail to the bureau (Lagden, 2014), may have a particularly strong effect even if subsequent, different training is given once back in force, due to the effects of belief perseverance (Guenther & Alicke, 2008).

Page | 36 There is a considerable body of psychological research into expertise and what it means to be an expert. It is acknowledged that a fundamental requirement in the development of expertise is receiving feedback (Ericsson & Lehmann, 1996). There are different types of feedback which target different aspects of the performance of an individual. Outcome feedback provides feedback solely in relation to the outcome of a decision, whilst cognitive feedback provides the decision maker with a measure of their cognitive processes used to come to a decision (Shepherd & Zacharakis, 2002). Cognitive feedback has been found to be more effective than outcome feedback (Shepherd & Zacharakis, ibid). It is unlikely that laboratory practitioners receive cognitive feedback. Whilst they may, on occasion, receive outcome feedback in relation to fingermark submissions to the laboratory (Earwaker et al, 2015), cognitive feedback would require a knowledge of the decision mechanisms involved in fingermark submission currently not available. Shepherd and Zacharakis (ibid) argue that decision aids are a useful tool for allowing cognitive feedback, particularly in cases in which outcome feedback is not readily available. This may be an approach that could be used to improve feedback within fingermark submission. However, the effect of feedback on performance has not consistently been positive. Kluger et al. (1996) conducted a review of the effect of feedback interventions on performance, finding that early studies concentrated on ‘knowledge of results (KR)’ (outcome feedback). They found that there were confounding findings in relation to the effect of KR on performance, but that issues concerning research methodology and data analysis were not discussed, and positive results were selectively cited over negative findings, perpetuating the belief that KR is successful in improving performance (Kluger et al., ibid). The presence or absence of feedback to laboratory practitioners may be an influencing factor in practitioner decision making performance. As such it is important to be aware of current processes in relation to feedback when investigating the effectiveness of decisions made within the laboratory. It would seem that there may be differences in the decision making performance of practitioners who have closer working relationships with their fingerprint bureaux, or work from the same site, allowing more frequent feedback.

2.6.3. Existing research into practitioner submission decision making

Research into the effectiveness of fingerprint sufficiency decision making has focussed on examiner decision making during the ACE-V process. Langenburg et al. (2009) acknowledged that fingerprint evidence had been challenged in the case of Minnesota vs Columbus under the Frye admissibility criteria (that if the method is generally accepted within the community then it will be accepted in the court) on the grounds that ACE-V methodology cannot be demonstrated to be reliable. As such they identified the need for a validation, or ‘method performance’ study for the use of the ACE-V process by fingerprint examiners. They carried out a three phased experimental process investigating the

Page | 37 repeatability and reliability of the ACE-V process, finding that examiners were reasonably consistent in their judgements and finding a limited number of false positive and false negative decisions (Langenburg, 2009).

It is important to establish whether the processes used by fingerprint laboratories are effective in filtering out poor quality fingermarks that would be useless to an examiner, and retaining fingermarks of sufficient quality for an examiner to analyse. Very little research has been published exploring the practical reality of this situation.

A study by Neumann et al. (2011), however, examined the evidential value of fingermarks that were discarded within a US fingerprint laboratory, aiming to establish the cost effectiveness of this process. Examination of a sample of partial fingermarks that were discarded by laboratory staff and scene of crime officers led to a small (2.3%) increase in evidence at an estimated cost of $138,000, suggesting that very few exploitable fingermarks are not recovered and that disproportionate investment would be required to progress these marks. However, this estimate, presumably, takes into account further processing of all discarded marks to yield a small percentage of results, not just those that would lead to an identification, suggesting that more effective decision-making could limit this cost by focussing resources at a more accurate submission threshold. Results also showed that the filtering process of submission to examiners was successful, with only a small proportion of insufficient marks being submitted by the laboratory. This would seem to suggest that fingerprint laboratories are reasonably successful in their role of submitting fingermarks to examiners that are of sufficient quality for comparison, and discarding marks of insufficient value, resulting in a system that is fairly cost effective and suggesting that there are not, in practice, significant differences in the abilities of ‘novices’ and ‘experts’ to assess the value of fingerprint ridge detail.

However, Neumann et al. (ibid) did discover that fingermarks were discarded by laboratory staff which contained very large numbers of minutiae, leading to discussion about the need to be more scientifically robust in this area of decision making. The study does not distinguish between fingermarks that were recovered by scene of crime officers and those recovered by the laboratory practitioner. There is benefit in making a distinction between these two sets of results as training, working environments, policies and procedures vary considerably between these two occupations. The results reported are based on the decisions of only one laboratory practitioner and four fingerprint examiners in a small US laboratory. Given the amount of intra-variability in novice analysis ability highlighted by Schiffer and Champod (2007), it would seem important to carry out similar research with a larger sample of laboratory staff in order to be able to generalise the results beyond this laboratory.

Page | 38 Earwaker et al. (2015) carried out a study that looked to assess the efficiency of the fingermark submission process within a UK laboratory, in relation to the requirements for the customer, their internal fingerprint bureau. A task was devised that allowed for the ‘ground truth’ in terms of sufficiency for comparison to be determined for a series of ambiguous fingermarks (those considered borderline for submission to a bureau). This involved internal examiners attempting to identify the fingermarks back to source, thus establishing whether or not they were of sufficient quality to be compared. Once this usability determination was established fingermarks were given to 11 practitioners from the Fingerprint Enhancement Laboratory of the Metropolitan Police Service who were asked to state whether or not they would submit each mark to the bureau. Responses given by the practitioners were compared to the usability determination of the examiners. The study found that 34% of the decisions made by practitioners in relation to the experimental marks were erroneous in relation to the usability determination of the examiners. Of this erroneous percentage of decisions half were decisions to submit a fingermark that was of too poor a quality for comparison (a false positive error) and half were decisions to discard a fingermark that was of sufficient quality for comparison (a false negative error) (Earwaker et al., 2015).

The present thesis seeks to build upon the preliminary work included within Earwaker et al. (2015). Firstly, this thesis seeks to establish the repeatability of the findings within another UK fingermark visualisation laboratory. This is a valuable exercise in order to establish whether such a make-up of decision outcomes is unique to the Metropolitan Police Service or can equally be applied to other UK laboratories, given that the Metropolitan Police is distinctive in its training provisions which are provided in-house instead of at the College of Police National Training Centre (Hall, 2014), and given the potential differences in structure and communication between different scientific support departments across the UK (as discussed in section 2.3). Secondly, this thesis seeks to further explore the mechanisms behind the fingermark submission decision alongside the consideration of a number of pertinent areas of psychological study.