OPCIONES DE COMPENSACIÓN

The ability of fingerprints to theoretically individualise is justified based upon the uniqueness and permanence of friction ridge skin (Champod et al, 2004), resulting from multiple factors involved in the embryological formation of epidermal ridges (Ashbaugh, 1999, Kaye, 2003). Identification is based upon the assumption that the patterns formed by the epidermal ridges on every individual finger are unique and that they are distinguishable from the patterns on every other finger (Haber and Haber, 2008). However, there is a lack of empirical evidence to confirm the statistical nature of this uniqueness (Kaye, 2003). Empirical evidence for the statistical uniqueness of fingerprints, which would remove current inductive reasoning, could only be achieved by comparing the friction ridge skin of everyone who had ever lived; an unattainable goal. An attempt made to provide a statistical value for uniqueness for litigation purposes remains unpublished in the scientific press and has been criticised by Kaye (2003) for being inaccurate and badly designed. Even if statistical validation of theoretical uniqueness was achievable the practical ability to individualise from a fingerprint would still be dependent upon the methodology used.

Fingerprint comparison methodology through the implementation of the ACE-V process (SWGFAST, 2011) is a subjective and opinion driven discipline. This process has not been scientifically verified (Haber and Haber, 2008) and a lack of evidence that fingerprint examiners do indeed have expertise in identifying the source of fingermarks has been highlighted by Vokey et al. (2009). However, fingerprint practitioners and the courts still uphold a ‘strong faith in uniqueness and (virtual) freedom from error’ (Saks, 2010, p14), continuing to claim to individualise (Cole, 2014).

Error has, however, been shown to occur, most publicly with the misidentification of the Madrid bomber, but also in a number of other cases of misattribution (Cole, 2005). DNA analysis techniques, which have achieved statistical validity for identification, can now exceed the reliability of fingerprint evidence, leading to an increased overturning of fingerprint convictions, as in the case of Stephen Cowens (Cole, 2005, 2006). This illustrates the paradoxical position that ‘good’ evidence holds; with

Page | 30 less other evidence able to challenge it, it is less challenged and so strengthened, meaning that flaws can go undetected (Cole, 2006). This may suggest the potential for further cases of wrongful convictions based upon erroneous fingerprint evidence. The terminology and meaning of error within forensic science is discussed further within section 2.7.

There is now healthy, multidisciplinary debate about how to ensure the continued legal acceptance of fingerprint evidence and increase its validity (Koehler, 2008), with approaches divided between the validation of ACE-V methodology or basing testimony solely on expertise (Haber and Haber, 2008). Mnookin (2008) advocates a system based solely on expertise to avoid validation of ACE-V whilst also claiming that the historical successful use of fingerprint evidence, as demonstrated in cases where it has been corroborated by other evidence, has itself provided ‘naturalistic’ evidence that the methodology works. This approach is criticised by Haber and Haber (2008) who question the independent nature of corroborative evidence, and point out that ACE-V methodology may not have been used in all such cases. Champod (2008) argues that experts should shift from stating that they are 100% certain of their conclusions to testifying on the probability of an accurate identification and that more research should be done to provide statistical validation for the ACE-V method.

Such debate demonstrates the ‘paradigm shift to a science based science’ (Saks & Koehler, 2010) in certain areas of methodology validation. However, this leaves out a fundamental component of examination methodology; the examiner himself. The FBI Laboratory Committee acknowledged the subjective nature of the work of a fingerprint examiner, referring to the examiner as a ‘black box’ and stating that ‘one may not know, understand, or appreciate the machinations that the examiner made to arrive at a conclusion’ (Budowle, et al, 2006). It would seem essential that the same scientific rigour that is being employed to validate founding principles and methodology should also be applied to a better understanding and calibration of the ‘black boxes’ responsible for the subjective ‘machinations’ of fingerprint examiners. It is no longer sufficient to fall back on previous reliable results to have confidence in the reliability of this subjective decision making process, instead forensic science needs to attempt to better understand the ‘black boxes’ of criminalists, not just wait for the inevitable Popperian ‘black swan’ (Keuth, 2005).

The forensic science community is, indeed, becoming increasingly aware of the psychological issues associated with human examiners making subjective decisions. Normative psychological theory suggests a probabilistic, Bayesian type approach to decision-making, with the keyassumption that the decision-maker is a rational actor who analyses decisions based upon probabilities and utilities (Hardman, 2009).It seems unlikely that this rational, economical model be said to be true of forensic scientist decision-makers, rather, that pressure and the highly emotional context of the decision may

Page | 31 cause the scientist to act irrationally. Kahneman et al. (1982) argue that a departure from rationality occurs due to the effect of heuristics, resulting in quicker decisions based on ‘rules of thumb’, or relying on external biasing information when the data present does not lead to a clear decision (Kahneman et al., 1982, Schiffer & Champod, 2007).

2.5.

‘Cognitive forensics’ – a developing field

There is a current flux of studies highlighting the presence of biasing effects within the interpretation of forensic evidence. These effects include confirmation bias (the tendency to conform to a pre- conceived hypothesis), contextual bias (being influences by the context in which a decision is made) and belief perseverance (the tendency to accept information that supports a pre-held believe and discount information that contradicts this belief) (Kassin et al., 2013). Biasing effects have been demonstrated to occur in the disciplines of DNA analysis (Dror & Hampikian, 2011), handwriting analysis (Found & Ganas., 2013), odontology (Page et al., 2012), bite mark analysis (Osborne et al, 2014) and anthropology (Nakhaeizadeh et al., 2014). Equally, studies within the domain of fingerprinting have shown biasing effects to occur (Fraser-Mackenzie et al., 2013, Earwaker et al, 2015), and recommendations have been made to reduce such unwanted effects (Dror, 2009, Wells et al., 2013, Garrett, 2013, Dror, 2016).

The best approach to take in order to understand and compensate for failings inherent in the ‘black box’ examiner is currently a hot topic for debate. Views are divided as to whether the most sensible approach is to remove the need for an examiners subjective view through relying on an objective computer generated probabilistic match determination within the pattern matching disciplines (increasing objectivity), or whether it is preferable to concentrate on exploring and correcting for the cognitive effects occurring when examiners are making these subjective decisions (improving subjective performance).

Champod (2014) highlights the recent focus upon research that investigates the effects of cognitive bias within subjective forensic science. Indeed, ‘bias’ can be considered to have become a popular buzz-word within research, conferences and meetings, and a motivator for organisational change within the domain. Champod (ibid) suggests, however, that a disproportionate focus of research into subjective decision making is preventing progress in increasing the objectivity with which forensic scientists can interpret evidence through a better understanding of the forensic traces themselves. Risinger et al., (2014) however, argue that there is not, in fact, an overrepresentation of research into cognitive bias within forensic science, and that research which establishes the existence and prevention of cognitive bias and that which leads to the more objective use of trace evidence need not be mutually exclusive. Buckleton et al. (2014) use the illustration of the ‘human machine’,

Page | 32 suggesting that there is a middle ground; forensic science needs to be undertaken more objectively as a result of a greater understanding of the fundamental principles of the discipline, whilst also ensuring that ‘human machinery’ is calibrated and its error rate is acknowledged. Buckleton et al. (ibid) propose that the existence of bias within forensic science has been sufficiently proven and that it is acceptance and action that now require further attention.

Forensic science, by nature, is a multidisciplinary domain which requires the application, with scientific rigor, of scientific disciplines to a forensic context. In recent years the forensic sciences have been criticised for not achieving this requirement and of lacking scientific integrity (Saks, 2010). With this in mind it would seem that there is indeed an imbalance in the current pool of research in relation to ‘cognitive forensics’. Research that looks to increase the objectivity of the discipline through gaining a better knowledge of the fundamental properties of forensic traces and developing a statistical approach is rich in contributors from a plethora of disciplines including (but not limited to) biologists, chemists, and statisticians. Publications putting forward statistical methods often include a detailed account of the mathematical basis for these propositions (Abraham et al., 2013a). Research into the subjective aspect of practitioner decision-making, however, appears to often lack such a rigorous scientific underpinning. Whilst eminent figures from within the domain of cognitive neuroscience are figureheads for psychological research within forensic science it would appear that the majority of the underlying neuroscience behind the cognitive effects exposed through research is not often communicated to the forensic science community. It would seem that research into the subjective decisions made by practitioners would benefit from a greater theoretical background. Triplett (2013) points out that, whilst a number of solutions to the ‘bias problem’ have been proposed (Kassin et al., 2013), subjectivity and bias may actually be symptoms of other causes; it could be the over use of the ‘bias’ buzz word is limiting research which could lead to a more comprehensive understanding of the psychological mechanisms behind faulty decision making within forensic science, and so provide more effective solutions.

A greater fundamental understanding of the psychological effects that are at play is crucial to establishing the extent to which research that establishes that cognitive bias is occurring should continue. It has been suggested that there has been sufficient research to suggest that bias affects forensic practitioners (Champod, 2014) and that, as we now know that bias occurs within forensic science, further effort to identify the presence of bias within additional specialisms and processes within the domain is unnecessary. This argument implies that all practitioners carrying out all processes within forensic science are being affected in the same way by the same psychological effects. It equally implies, albeit indirectly, that the documented solutions for bias affects will be universally effective. An initial criticism to this assumption is that there is currently a lack of empirical

Page | 33 research demonstrating the effectiveness of any of the solutions proposed, suggesting that further research in this area is required before such solutions are widely implemented and the problem is considered to be solved. Additionally, it would seem that the only way to establish whether or not further research needs to be undertaken to establish the presence of biasing effects in novel forensic situations is to gain, through sound empirical research, a greater knowledge of the psychological effects themselves, so as to be more aware of the exact vulnerabilities of forensic practitioners. Given the differences between processes carried out within forensic science, such as the case and workplace pressures, information present, and exact cognitive processes involved, and also differences related to the same procedure being carried out in a different laboratory, or by a different practitioner at a different point in time, it would seem imperative to fully understand the effects at play in order to be able to adopt the most appropriate solution in each case, be this at a systemic or an individual level. This would also enable the continued gain of further information in relation to situations in which practitioners are vulnerable to cognitive effects in order to build up a more complete picture to inform effective targeted solutions.

As such, the present thesis seeks to carry out research which looks to investigate decision making at an early stage of the fingerprint evidential process during the fingerprint practitioner fingermark submission decisions, and to consider this decision in terms of applicable psychological approaches.

2.6.

Why investigate decision making within the practitioner fingermark