The Utility of Expanded Conclusion Scales During Latent Print Examinations

During fingerprint comparisons, a latent print examiner visually compares two impressions to determine whether or not they originated from the same source. They consider the amount of perceived detail in agreement or disagreement and accumulate evidence toward same source and different sources propositions. This evidence is then mapped to one of three conclusions: Identification, Inconclusive, or Exclusion. A limitation of this 3-conclusion scale is it can lose information when translating the conclusion from the internal strength-of-evidence value to one of only three possible conclusions. An alternative scale with two additional values, support for different sources and support for common sources, has been proposed by the Friction Ridge Subcommittee of OSAC. The expanded scale could lead to more investigative leads but could produce complex trade-offs in both correct and erroneous identifications. The aim of the present study was to determine the consequences of a shift to expanded conclusion scales in latent print comparisons. Latent print examiners each completed 60 comparisons using one of the two scales, and the resulting data were modeled using signal detection theory to measure whether the expanded scale changed the threshold for an “Identification” conclusion. When using the expanded scale, examiners became more risk-averse when making “Identification” decisions and tended to transition both the weaker Identification and stronger Inconclusive responses to the “Support for Common Source” statement. The results demonstrate the utility of an expanded conclusion scale and also provide guidance for the adoption of these or similar scales.     

Cognitive biases in the peer review of bullet and cartridge case comparison casework: A field study

ObjectiveForensic judgments and their peer review are often the result of human assessment and are thus subjective and prone to bias. This study examined whether bias affects forensic peer review.HypothesesWe hypothesized that the probability of disagreement between two forensic examiners about the proposed conclusion would be higher with “blind” peer review (reviewer saw only the first examiner’s comparison photos) than with “non-blind” peer review (reviewer also saw the first examiner’s interpretation and proposed conclusion). We also hypothesized that examiners with a higher perceived professional status would have a larger effect on the reported conclusion than examiners with a lower status.MethodWe acquired data during a non-blind and a blind peer review procedure in a naturalistic, covert study with eight examiners (3–26 years of experience). We acquired 97 conclusions of bullet and cartridge case comparisons in the blind and 471 in the non-blind peer review procedure.ResultsThe odds of disagreement between examiners about the evidential strength of a comparison were approximately five times larger (95%-CI [3.06, 8.50]) in the blind than in the non-blind procedure, with disagreement about 42.3% and 12.5% of the proposed conclusions, respectively. Also, the odds that their proposed conclusion was reported as the final conclusion were approximately 2.5 higher for the higher-status examiners than for lower-status examiners.ConclusionsOur results support both the hypothesis that bias occurs during non-blind forensic peer review and the hypothesis that higher-status examiners determine the outcome of a discussion more than lower-status examiners. We conclude that blind peer review may reduce the probability of bias and that status effects have an impact on the peer reviewing process.     

论笔迹鉴定结论的证据效力——兼谈“世纪遗产争夺案”的笔迹鉴定

笔迹鉴定在现代诉讼中日益增多,因其鉴定多依赖于＂经验知识＂,不具有可验证的重复性,也无法接受实证的重复性检验,致使其在作为证据使用时存在一定的分歧,尤其是遗嘱笔迹因书写人死亡,其鉴定结果更富有争议。香港历经＂八年＂旷日持久的＂世纪遗产争夺案＂中的笔迹鉴定颇具典型意义。笔迹鉴定结论如何在法庭中出示以及法庭对有争议的笔迹鉴定结论如何采纳或者排除,既是一个理论问题,又是一个制度问题,还是一个价值选择问题。因此,对笔迹鉴定结论的研究与探讨成为司法鉴定制度和证据制度必须直面的带有现实意义的问题。     

What does a digital forensics opinion look like? A comparative study of digital forensics and forensic science reporting practices

This study explores digital forensics (DF) reporting practices and compares the results with other forensic science disciplines. Forty reports were obtained from a quasi-experiment involving DF examiners, and a quantitative content analysis was performed to determine which conclusion types they applied and which content they included with relevance to the credibility of the reported results. A qualitative analysis was performed to examine the certainty expressions used in the conclusions. The results were compared to a study of eight forensic science disciplines performed by Bali et al. [24,26]. The results show that the DF examiners tend to present their conclusions either as Categorical conclusion or Strength of support (SoS) conclusion types and that they address source, activity, and offence level issues in their conclusions. The content analysis indicates deficiencies in DF reporting practices, and several of the challenges seem to be shared with other FS disciplines. The analysis of certainty expressions showed that a plethora of expressions was used, and that they lacked reference to an established framework. The results indicate that more research on DF evaluation and reporting practices is necessary and justifies a need for enhanced focus on quality control and peer review within the DF discipline.     

Measuring the Rarity of Fingerprint Patterns in the Dutch Population Using an Extended Classification Set

Latent print examiners often use their experience and knowledge to reach a conclusion on the identity of the source. Their conclusion is primarily based on their personal opinion on the rarity of the matching fingerprint features. Fingerprint patterns, if present, can play a significant role in the final assessment of a match. The authors believe that statistical data on the rarity of fingerprint patterns strengthens the subjective evaluation of the corresponding information. In order to provide fingerprint examiners with additional numerical support, fingerprint patterns were manually classified in a set of 24,104 fingerprints. In this study the frequencies of occurrence of 35 different fingerprint patterns have been obtained. The frequency data presented in this study can be used in the ACE‐V process applied in forensic casework, allowing for the assessment of the evidential strength related to a specific fingerprint pattern type.     

Application of likelihood ratios for firearm and toolmark analysis

Historically firearm and toolmark examiners have rendered categorical or inconclusive opinions and eschewed probabilistic ones, especially in the United States. We suggest this practice may no longer be necessary or desirable, and outline an alternative approach that is within a comprehensive logical/Bayesian paradigm. Hypothetical forensic and non-forensic examples are provided for readers who are practicing firearm and toolmark examiners, and the strengths and weaknesses of both approaches are considered.     

Microscopical discrimination of human head hairs sharing a mitochondrial haplogroup

In forensic analyses, determining the level of consensus among examiners for hair comparison conclusions and ancestry identifications is important for assessing the scientific validity of microscopical hair examinations. Here, we present data from an interlaboratory study on the accuracy of microscopical hair comparisons among a subset of experienced hair examiners currently analyzing hair in forensic laboratories across the United States. We examined how well microscopical analysis of hair can reliably be used to differentiate hair samples, many of which were macroscopically similar. Using cut hair samples, many sharing similar macroscopic and microscopic features, collected from individuals who share the same mitochondrial haplogroup as an indication of genetic relatedness, we tested multiple aspects that could impact hair comparisons. This research tested the extent to which morphological features related to ancestry and hair length influence conclusions. Microscopical hair examinations yielded accurate assessments of inclusion/exclusion relative to the reference samples among 85% of the pairwise comparisons. We found shorter hairs had reduced levels of accuracy and hairs from populations examiners were not familiar with may have impacted their ability to resolve features. The reliability of ancestry determinations is not yet clear, but we found indications that the existing categories are only somewhat related to current ethnic and genetic variation. Our results provide support for the continued utility of microscopical comparison of hairs within forensic laboratories and to advocate for a combined analytical approach using both microscopical analysis and mtDNA data on all forensic analyses of hair.     

Novices cannot fill the examiners’ shoes: Evidence of footwear examiners’ expertise in shoe comparisons

The value of a footwear examiner’s opinion centres on their ability to determine whether a particular shoe made an impression with greater accuracy than a novice. However, there has been limited research on the expertise of footwear examiners and the accuracy and reproducibility of their decisions. In the current study, we measured the accuracy and consensus of 31 footwear examiners versus a comparison group of 29 novices. Participants completed 20 ground truth known mock shoe comparisons. Results demonstrated that footwear examiners were more accurate than novices, regardless of comparison difficulty. Overall, on trials where probative decisions were given, examiners made false identifications and false exclusions on a total of 3% and 2% of trials, while novices made false identifications and false exclusions on a total of 19% and 17% of trials. Examiners also demonstrated better consensus in their opinions than novices, although both groups demonstrated low levels of agreement in their responses and variability in their interpretation of the conclusion scale. In summary, these findings support the proposition that footwear examiners show expert-level performance in matching known and unknown footwear impressions. These performance estimates may help the criminal justice system to appropriately value footwear examination evidence.     

Battered woman and public opinion: Some realities about the myths

Expert testimony regarding the battered woman syndrome is often presented at trial on behalf of women charged with killing their batterers. Where courts have admitted such testimony into evidence, they have done so on the theory that the testimony is needed to dispel common myths regarding battered women—e.g., erroneous beliefs that battered women are masochists, who are somehow responsible for the battering they suffer and could avoid being battered by simply leaving their batterers. To date, however, there is no published empirical evidence that either jurors or members of the public at large hold such erroneous beliefs. The results of this study provide empirical support for the judicial hypothesis. These results suggest that many members of the general public eligible for jury duty do, in fact, hold erroneous, stereotyped beliefs about battered women.     

Anxiety disorders and intimate partner violence: can the association be explained by coexisting conditions or borderline personality traits?

Intimate partner violence (IPV) is a serious, preventable public health problem. IPV perpetration is strongly associated with Anxiety disorders at the population level. We investigated whether the association could be explained by coexisting psychiatric conditions or Borderline personality traits, using a combined data-set of two National Household Surveys (n = 15,973). Results showed women were more likely to report perpetrating IPV than men. Anxiety disorders were associated with IPV. When coexisting psychiatric conditions together with a categorical diagnosis of Borderline Personality Disorder (BPD) were investigated as explanatory variables, 19.2% of the association between Anxiety disorders and IPV was explained. Using individual Borderline traits in place of a categorical diagnosis of BPD, 58.3% of the association was explained. In conclusion, the association between Anxiety disorders and IPV was partly, but not fully, explained by coexisting psychiatric conditions and individual Borderline traits. Perpetrators of IPV should be screened for Anxiety disorders and among those with Anxiety disorders, Borderline traits are important.     

Firearm examination: Examiner judgments and computer‐based comparisons

Forensic firearm examination provides the court of law with information about the source of fired cartridge cases. We assessed the validity of source decisions of a computer‐based method and of 73 firearm examiners who compared breechface and firing pin impressions of 48 comparison sets. We also compared the computer‐based method's comparison scores with the examiners' degree‐of‐support judgments and assessed the validity of the latter. The true‐positive rate (sensitivity) and true‐negative rate (specificity) of the computer‐based method (for the comparison of both the breechface and firing pin impressions) were 94.4% and at least 91.7%, respectively. For the examiners, the true‐positive rate was at least 95.3% and the true‐negative rate was at least 86.2%. The validity of the source decisions improved when the evaluations of breechface and firing pin impressions were combined and for the examiners also when the perceived difficulty of the comparison decreased. The examiners were reluctant to provide source decisions for "difficult" comparisons even though their source decisions were mostly correct. The correlation between the computer‐based method's comparison scores and the examiners' degree‐of‐support judgments was low for the same‐source comparisons to negligible for the different‐source comparisons. Combining the outcomes of computer‐based methods with the judgments of examiners could increase the validity of firearm examinations. The examiners' numerical degree‐of‐support judgments for their source decisions were not well‐calibrated and showed clear signs of overconfidence. We suggest studying the merits of performance feedback to calibrate these judgments.     

对『司法会计鉴定结论能否回答法律性问题』的思考

司法会计鉴定结论是法定证据之一.由于司法会计技术人员一般都具备较高的综合素质,司法会计鉴定与查帐报告和审计结论有质的区别,司法会计技术人员对案件过程有比较全面的了解,对案件性质有比较深刻的认识,因此,司法会计鉴定结论对法律问题不应当采取一概回避或一律排斥的态度.又由于司法会计技术人员不具备对案件定性的权力,司法鉴定在本质上是一种科学研究活动,决定了它只能有限制地回答部分与鉴定要求有关的法律问题.     

Secondary victimization and the collective identity of crime victims: a qualitative analysis of Swedish crime news discourse

This article presents an analysis of how secondary victims of murder—in this context, the parents or close family members of a primary murder victim—are represented in Swedish crime news discourse. The study is based on a discourse analysis of media coverage of secondary victims, and statements made by them, in relation to four highly publicized murder cases during the last two decades. The analysis shows that portrayals of secondary victimization reinforce the conflictual character of victim–offender relationships in the news, but also limit the conditions for talking about the significance of social support, mediation and reconciliation for crime victims. News representations of crime victims become less clearly marked by the characteristics of the ‘ideal’ victim as secondary victims, and persons who are explicitly critical toward the legal system, claim victimhood. Furthermore, the identity of the crime victims’ movement as a collective becomes destabilized when the category of the victim is widened to include individuals whose interests are framed as subjective, rather than related to the needs of other crime victims or the general public. In sum, increased media focus on secondary victims may thus undermine the legitimacy of victim claims in public discourse.     

Organizational and Human Factors Affecting Forensic Decision-Making: Workplace Stress and Feedback

Although forensic examiners operate in a stressful environment, there is a lack of understanding about workplace stress and feedback. These organizational and human factors can potentially impact forensic science judgments. In this study, 150 practicing forensic examiners from one laboratory were surveyed about their experiences of workplace stress, and the explicit and implicit feedback they receive. Forensic examiners reported that their high stress levels originated more from workplace-related factors (management and/or supervision, backlogs, and the pressure to do many cases) than from personal related factors (family, medical, and/or financial). The findings showed that a few (8%) of the forensic examiners sometimes felt strong implicit feedback about what conclusions were expected from them and that some (14%) also strongly felt that they were more appreciated when they helped to solve a case (e.g., by reaching a “match” as opposed to an “inconclusive” conclusion). Differences were found when comparing workplace stress and feedback levels across three core forensic science fields (forensic biology, chemistry, and latent prints) and across career stages (early, mid, and late). Gaining insights into the stress factors within a workplace and explicit and implicit feedback has implications for developing policies to improve the well-being, motivation, and performance of forensic examiners.     

The utility of sex offender registration: a research note†

ABSTRACT

Sex offender registries are one of the more hotly debated and polarising topics in criminology. Registries are generally perceived as valuable by the public, legislators, and law enforcement. However, academics and treatment providers have largely remained critical, arguing registries are costly and ineffective. Continued support despite these claims has led some scholars to suggest that proponents are unaware of evidence, indifferent to science, and perhaps driven by emotions. Yet this conclusion denies important facts. First, statistical evidence shows that registrants are at far higher risk of committing a sex crime than the general public. Second, high-quality empirical research suggests that enacting registries is associated with significant decreases in sex offences. Third, there is prima facie evidence that registration has assisted in police investigations and prevented sexual crimes. Recognising these arguments is likely an important step towards improving the quality of debate, science, and policy on registration.     

The Patent Examiner Sweepstakes

This article presents evidence that patent value varies with random examiner assignment at the U.S. Patent Office. Prior work analyzed firm growth as a function of review by “easy” examiners who grant patents at a high rate. The current research looks past whether a patent is granted and instead focuses on how assignment to an “easy” or “hard” examiner influences the attributes of resultant patents. Focusing on their propensities to reject applications on novelty or obviousness grounds, analysis finds that patents issued by lenient examiners tend to be broader in scope, are more valuable to their owners, and elicit a larger stock market response when granted. Further analysis quantifies the level of variation (“noise”) among examiners. This inquiry finds that the noise level in issuing novelty rejections decreases with examiner experience, while variation among examiners issuing obviousness rejections actually increases with experience. A third line of investigation presents evidence that “stricter” examiners disproportionately reach the correct examination relative to more lenient counterparts. This conclusion is supported by “twin application” analysis comparing outcomes of related U.S. and European applications. Consistent with the literature using this method, the European Patent Office's outcome is considered the “gold standard” for examination, and thus, its decision to grant or deny is assumed correct.     

Shoe print examinations: effects of expectation, complexity and experience

Even though trace evidence is becoming more and more important in legal cases, only little is known about the influence of task and context factors on comparative judgments. In the present study we investigated how expectations and complexity affect shoe print examinations and to what extent differences exist between beginners and experienced examiners. Twelve examiners assessed similarity between a shoe print and a shoe for eight different cases. For half the cases expectation was induced by providing additional incriminating evidence. A complex case meant that the print was relatively noisy, for example because the perpetrator rotated his foot. A simple case meant that the print was clear. The results showed that there was no effect of expectation and no effect of experience. Only complexity affected the examiners' assessments: when the background was noisy, the acquired features received a lower evidential value than when the background was clear. Apparently, examiners compensated for the quality of the print and were more cautious in drawing conclusions when prints were less clear. Even though the results allow for some optimism with regard to the influence of expectations on shoe print examinations, it has to be taken into account that the Dutch procedure is supported by a formal guideline, which may (partly) explain the present findings.     

Forensic DNA retention: Public perspective studies in the United Kingdom and around the world

This review analysed public perspective studies on forensic DNA retention in the United Kingdom and around the world. The studies generally show strong public support for the long-term or indefinite retention of DNA from convicts and suspects. There is considerable support for the retention of DNA from all or some arrestees and potentially the entire population. This was predicated upon the belief that forensic DNA databases have crime-solving abilities, which the public rate highly. In the UK, it was found that the current Protection of Freedoms Act 2012 regime is broadly representative of the recommendations of the surveyed British public. Nevertheless, the studies highlighted a gap in forensic DNA education among the public, suggesting that public views may not be well informed. Overall, there was clear evidence of privacy concerns and the potential misuse of DNA records among the public, with a significant number opposing the retention of DNA from the innocent. It was found that most of the studies were qualitative or non-representative of the relevant population, limiting the generalisation of the results. There was also limited studies among a representative sample of primary stakeholders who are well-informed or directly exposed to the benefits, challenges and risks associated with DNA retention. A research into stakeholders rating of different forensic DNA retention regimes is therefore highly recommended. This is important because the studies suggest divergent views among criminal justice professionals and other members of the public, with the former expressing expansive views and the latter expressing restrictive views. The primary stakeholder's survey will help establish whether the relevant safeguards have been put in place to protect both public security and individual interests.