Performance evaluation of automated fingerprint identification systems for specific conditions observed in casework using simulated fingermarks

Few studies have been reported on the performance evaluation of automated fingerprint identification systems (AFIS) for fingermark-to-fingerprint comparisons. This paper aims to illustrate to fingerprint examiners the relevance of evaluating the AFIS performance under specific conditions by carrying out five types of performance tests. The conditions addressed are the number of minutiae assigned to a fingermark, manual and automatic assignment of the minutiae, the finger region from which the fingermark originates, the degree of distortion in the fingermark, and the difference in orientation between fingermarks and fingerprints. In these tests, the magnitude of the influence for each condition was quantified. The comparisons were performed using a research AFIS technology with simulated fingermarks. Simulated fingermarks provide a practical way to create fingermarks for specific conditions in large quantities. The results showed that each condition influences the performance significantly, emphasizing the relevance of developing, and applying performance tests for specific conditions.     

指纹特征点区域分布规律应用研究

目的 针对指纹自动识别系统评分机制所存在的局限性,探讨根据指纹特征点分布进行加权的方法.方法 通过总结大量人群指纹特征点区域分布规律,按照分布密度在计算中进行加权.结果 在对反查指纹加权计算的试验中,同一指纹加权后的分数相比其它指纹得到了提高.结论 采用此种加权机制,对于现有基‘于特征点的指纹自动识别系统准确率提高是有效的.     

Cognitive and contextual influences in determination of latent fingerprint suitability for identification judgments

We examined forensic fingerprint examiners' suitability determinations of latent fingerprints comparing situations in which the latent is assessed solo (in isolation) versus situations in which it is presented alongside a comparison (matching or non-matching) exemplar print. The presence of a non-matching comparison exemplar led examiners to be more inclined to draw the conclusion that the latent was suitable for comparison compared to when the latent was presented solo. This effect persisted even when the latent presented was highly unsuitable for comparison. The presence of a matching comparison exemplar led examiners to be less likely to decide that the latent was suitable and more likely to decide the latent was questionable compared to solo analysis. This effect persisted even when the latent presented was highly suitable, suggesting a strong main effect. Knowledge of another examiner's previous determination that the latent was unsuitable was found to increase the likelihood that the examiner would conclude that the latent was unsuitable. However, knowledge of a previous “suitable” determination by another examiner did not increase the likelihood of a “suitable” conclusion by examiners. The finding that effects were weaker, although not entirely removed, in those with IAI certification suggests that training may be an appropriate route for reducing the effect of contextual influence and bias in suitability determinations. It was also shown that latent prints that were previously classed as "unsuitable" in a non-biasing context, continued to be judged to be "unsuitable" in a strongly biasing context (a major case in which a previous examiner was purported to have made an Individualization).     

Computation of likelihood ratios in fingerprint identification for configurations of three minutiae

Recent challenges to fingerprint evidence have brought forward the need for peer-reviewed scientific publications to support the evidential value assessment of fingerprint. This paper proposes some research directions to gather statistical knowledge of the within-source and between-sources variability of configurations of three minutiae on fingermarks and fingerprints. This paper proposes the use of the likelihood ratio (LR) approach to assess the value of fingerprint evidence. The model explores the statistical contribution of configurations of three minutiae using Tippett plots and related measures to assess the quality of the system. Features vectors used for statistical analysis have been obtained following a preprocessing step based on Gabor filtering and image processing to extract minutia position, type, and direction. Spatial relationships have been coded using Delaunay triangulation. The metric, used to assess similarity between two feature vectors is based on an Euclidean distance measure. The within-source variability has been estimated using a sample of 216 fingerprints from four fingers (two donors). Between-sources variability takes advantage of a database of 818 ulnar loops from randomly selected males. The results show that the data-driven approach adopted here is robust. The magnitude of LRs obtained under the prosecution and defense propositions stresses upon the major evidential contribution that small portions of fingermark, containing three minutiae, can provide regardless of its position on the general pattern.     

Experimental results of fingerprint comparison validity and reliability: A review and critical analysis

Our purpose in this article is to determine whether the results of the published experiments on the accuracy and reliability of fingerprint comparison can be generalized to fingerprint laboratory casework, and/or to document the error rate of the Analysis–Comparison–Evaluation (ACE) method. We review the existing 13 published experiments on fingerprint comparison accuracy and reliability. These studies comprise the entire corpus of experimental research published on the accuracy of fingerprint comparisons since criminal courts first admitted forensic fingerprint evidence about 120 years ago. We start with the two studies by Ulery, Hicklin, Buscaglia and Roberts (2011, 2012), because they are recent, large, designed specifically to provide estimates of the accuracy and reliability of fingerprint comparisons, and to respond to the criticisms cited in the National Academy of Sciences Report (2009).Following the two Ulery et al. studies, we review and evaluate the other eleven experiments, considering problems that are unique to each. We then evaluate the 13 experiments for the problems common to all or most of them, especially with respect to the generalizability of their results to laboratory casework.Overall, we conclude that the experimental designs employed deviated from casework procedures in critical ways that preclude generalization of the results to casework. The experiments asked examiner-subjects to carry out their comparisons using different responses from those employed in casework; the experiments presented the comparisons in formats that differed from casework; the experiments enlisted highly trained examiners as experimental subjects rather than subjects drawn randomly from among all fingerprint examiners; the experiments did not use fingerprint test items known to be comparable in type and especially in difficulty to those encountered in casework; and the experiments did not require examiners to use the ACE method, nor was that method defined, controlled, or tested in these experiments.Until there is significant progress in defining and measuring the difficulty of fingerprint test materials, and until the steps to be followed in the ACE method are defined and measurable, we conclude that new experiments patterned on these existing experiments cannot inform the fingerprint profession or the courts about casework accuracy and errors.     

A comparison of three automated DNA purification methods in Forensic casework

Manual Chelex^®-100 and organic extractions (phenol/chloroform) are used as routine methods at the Swedish National Laboratory of Forensic Science, SKL. The aim of this study was to find an automated DNA purification system to replace the organic method. The following methods were evaluated and compared to each other and to the organic method used routinely; BioRobot^® EZ1 with EZ1 DNA Investigator Kit and Card (Qiagen), iPrep™ Purification Instrument with iPrep™ ChargeSwitch^® Forensic Kit and Card (Invitrogen), Magnatrix™ 1200 Workstation with the Magnatrix™ gDNA Blood Kit Forensic and two different protocols; Forensic protocol A and B (Magnetic Biosolutions). Blood on fats, cotton swabs, moist snuff, paper towels and leather, post-mortem blood and muscle tissue were extracted with the different methods. DNA concentration and quality of the electropherograms were examined. Individual comparisons between the four extraction methods showed that iPrep™ and Magnatrix™ 1200 gave significantly lower mean quantities compared to BioRobot^® EZ1 and the organic extraction method (p < 0.05). There were no significant differences between the latter two. BioRobot^® EZ1 generated the best results and is in the process of being validated for routine analysis at SKL.     

Computation of likelihood ratios in fingerprint identification for configurations of any number of minutiae

Recent court challenges have highlighted the need for statistical research on fingerprint identification. This paper proposes a model for computing likelihood ratios (LRs) to assess the evidential value of comparisons with any number of minutiae. The model considers minutiae type, direction and relative spatial relationships. It expands on previous work on three minutiae by adopting a spatial modeling using radial triangulation and a probabilistic distortion model for assessing the numerator of the LR. The model has been tested on a sample of 686 ulnar loops and 204 arches. Features vectors used for statistical analysis have been obtained following a preprocessing step based on Gabor filtering and image processing to extract minutiae data. The metric used to assess similarity between two feature vectors is based on an Euclidean distance measure. Tippett plots and rates of misleading evidence have been used as performance indicators of the model. The model has shown encouraging behavior with low rates of misleading evidence and a LR power of the model increasing significantly with the number of minutiae. The LRs that it provides are highly indicative of identity of source on a significant proportion of cases, even when considering configurations with few minutiae. In contrast with previous research, the model, in addition to minutia type and direction, incorporates spatial relationships of minutiae without introducing probabilistic independence assumptions. The model also accounts for finger distortion.     

Saliva identification in forensic samples by automated microextraction and intact mass analysis of statherin

The enzyme α-amylase has long been a commonly targeted protein in serological tests for saliva. While being especially abundant in saliva, α-amylase is detectable in vaginal secretions, sweat, fecal matter, breast milk and other matrices. As a result, assays for α-amylase only provide a presumptive indication of saliva. The availability of mass spectrometry-based tools for the detection of less abundant, but more specific, protein targets (e.g., human statherin) has enabled the development of high confidence assays for human saliva. Sample throughput, however, has traditionally been low due to multi-step workflows for protein extraction, quantitation, enzymatic digestion, solid phase cleanup, and nano-/capillary-based chromatography. Here, we present two novel “direct” single-stage extraction strategies for sample preparation. These feature immunoaffinity purification and reversed-phase solid-phase microextraction in conjunction with intact mass analysis of human statherin for saliva identification. Mass analysis was performed on the Thermo Scientific Q-Exactive™ Orbitrap mass spectrometer with a 10-min analytical run time. Data analysis was performed using Byos^® from Protein Metrics. Two sample sets were analyzed with a population of 20 individuals to evaluate detection reliability. A series of casework-type samples were then assayed to evaluate performance in an authentic forensic context. Statherin was confidently identified in 92% and 71% of samples extracted using the immunoaffinity purification and solid phase microextraction approaches, respectively. Overall, immunoaffinity purification outperformed the solid phase microextraction, especially with complex mixtures. In toto, robotic extraction and intact mass spectrometry enable the reliable identification of trace human saliva in a variety of sample types.     

A comparison of multi-metal deposition processes utilising gold nanoparticles and an evaluation of their application to 'low yield' surfaces for finger mark development

This paper reports a comparison of the effectiveness and practicality of using different multi-metal deposition processes for finger mark development. The work investigates whether modifications can be made to improve the performance of the existing process published by Schnetz. Secondly, we compare the ability of different multi-metal deposition processes to develop finger marks on a range of surfaces with that of other currently used development processes. All published multi-metal deposition processes utilise an initial stage of colloidal gold deposition followed by enhancement of the marks with using a physical developer. All possible combinations of colloidal gold and physical developer stages were tested. The method proposed by Schnetz was shown to be the most effective process, however a modification which reduced the pH of the enhancement solution was revealed to provide the best combination of effectiveness and practicality. In trials comparing the modified formulation with vacuum metal deposition, superglue and powder suspensions on surfaces which typically give low finger mark yields (cling film, plasticised vinyl, leather and masking tape), the modified method produced significantly better results over existing processes for cling film and plasticised vinyl. The modified formulation was found to be ineffective on both masking tape and leather. It is recommended that further tests be carried out on the modified multi-metal deposition formulation to establish whether it could be introduced for operational work on cling film material in particular.     

Cognitive issues in fingerprint analysis: inter- and intra-expert consistency and the effect of a 'target' comparison

Deciding whether two fingerprint marks originate from the same source requires examination and comparison of their features. Many cognitive factors play a major role in such information processing. In this paper we examined the consistency (both between- and within-experts) in the analysis of latent marks, and whether the presence of a 'target' comparison print affects this analysis. Our findings showed that the context of a comparison print affected analysis of the latent mark, possibly influencing allocation of attention, visual search, and threshold for determining a 'signal'. We also found that even without the context of the comparison print there was still a lack of consistency in analysing latent marks. Not only was this reflected by inconsistency between different experts, but the same experts at different times were inconsistent with their own analysis. However, the characterization of these inconsistencies depends on the standard and definition of what constitutes inconsistent. Furthermore, these effects were not uniform; the lack of consistency varied across fingerprints and experts. We propose solutions to mediate variability in the analysis of friction ridge skin.     

Optimization and initial evaluation of 1,2-indandione as a reagent for fingerprint detection

1,2-Indandione has been used to develop fluorescent fingerprints on porous materials such as paper. The compound reacts with amino acid residues to produce highly fluorescent fingerprint ridges. An optimized formulation and treatment protocol for using the reagent is presented here. The reagent is applied as a solution in HFE7100 containing acetic acid and ethyl acetate. Treated articles are heated at 100 degrees C for 10 min at ambient humidity and stored in the dark before recording the fingerprints using fluorescence photography or digital imaging. Photodecomposition of the fluorescent fingerprints has been observed. Storage in the dark reduces degradation, extending the lifetime of the fingerprints. Other chemical methods to stabilize the fingerprints proved unsuccessful. Comparisons of the performance of 1,2-indandione with DFO in CFC113 performed on a limited range of substrates indicated that the reagent might be an effective method for the development of latent fingerprints despite the new reagent producing less intense fluorescence.     

Hair-MAP: a prototype automated system for forensic hair comparison and analysis

This paper demonstrates the feasibility of the automation of forensic hair analysis and comparison task using neural network explanation systems (NNESs). Our system takes as input microscopic images of two hairs and produces a classification decision as to whether or not the hairs came from the same person. Hair images were captured using a NEXTDimension video board in a NEXTDimension color turbo computer, connected to a video camera. Image processing was done on an SGI indigo workstation. Each image is segmented into a number of pieces appropriate for classification of different features. A variety of image processing techniques are used to enhance this information. Use of wavelet analysis and the Haralick texture algorithm to pre-process data has allowed us to compress large amounts of data into smaller, yet representative data. Neural networks are then used for feature classification. Finally, statistical tests determine the degree of match between the resulting collection of hair feature vectors. An important issue in automation of any task in criminal investigations is the reliability and understandability of the resulting system. To address this concern, we have developed methods to facilitate explanation of neural network's behavior using a decision tree. The system was able to achieve a performance of 83% hair match accuracy, using 5 of the 21 morphological characteristics used by experts. This shows promise for the usefulness of a fuller scale system. While an automated system would not replace the expert, it would make the task easier by providing a means for pre-processing the large amount of data with which the expert must contend.     

预防原则与科学依据在多边协定下的协调——以《生物安全议定书》与《实施卫生与植物卫生措施协定》为例

由于转基因活生物体及其产品对生物多样性、生态环境和人体健康可能产生潜在的有害影响,因此,无论《生物安全议定书》还是《实施卫生与植物卫生措施协定》都在具体内容中考虑了对转基因活生物体及其产品贸易的管理。但两者的目标理念有所不同,前者基于预防原则,后者基于科学依据,造成两者对同一内容的管理出现了矛盾。在世界科技经济愈加一体化的今天,势必需要协调措施以减小这种矛盾对社会进步、技术的发展和国际贸易可能造成的影响。本文即通过对两者的差异及共同点分析,提出协调建议。     

A comment on experimental results of fingerprint comparison validity and reliability: A review and critical analysis

We respond to the article “Experimental results of fingerprint comparison validity and reliability: A review and critical analysis” by Ralph and Lyn Haber which offers (a) a one-sided criticism of the state of affairs in latent print examination, (b) lack of original data supporting that their suggested approach, and (c) a host of incorrect statements, inaccuracies, or obscure interpretations of the existing data.     

The intergroup variability and sex dimorphism in the size of the human dental arches in personal identification]

The morphology of dental arch has been studied in representatives of 11 contrast (by anthropological characteristics) ethnic groups from regions of their compact residence. The sampling from each ethnic group consisted of 200 subjects (100 male and 100 female) aged 13-20 years. A total of 4,500 plaster models of dental arches were examined. The results were statistically processed using factor, canonical, discriminant analyses, and multidimensional scanning. The data on the variability and sex dimorphism in the size and shape of dental arches in subjects belonging to different ethnic groups may be practically significant in forensic medical personality identification.     

Multiplex amplification of mitochondrial DNA for human and species identification in forensic evaluation

We describe a method combining in a single-round polymerase chain reaction amplifications of both cytochrome b and hypervariable D-loop mitochondrial DNA allowing species determination and individual human identification. Following the amplification step, amplicons are first screened on an agarose gel. The presence of only one band indicates that the sample is nonhuman, while the presence of two bands indicates a human origin. Subsequent DNA sequencing of the hypervariable D-loop region DNA allows for individual human identification as the presence of cytochrome b fragment does not interfere with the analysis. Similarly, further species determination on the basis of the phylogenetically variable cytochrome b gene is possible by sequencing of the cytochrome b DNA fragment.     

Anthropological and radiographic comparison of vertebrae for identification of decomposed human remains

This case study demonstrates the importance of involving an anthropologist in forensic situations with decomposed remains. Anthropological consultation was used in conjunction with the comparison of antemortem and postmortem radiographs to establish positive identification of unknown, decomposed remains. The remains had no traditional identifying features such as fingerprints or dental. Through anthropological analysis, it was determined the decedent was male, between 20 and 23 years at time of death and c. 5'2' tall. This information allowed for a presumptive identification and a request for antemortem radiographs. The missing person was identified comparing the spinous processes of the cervical and thoracic vertebrae between ante- and postmortem radiographs.     

WTO知识产权国际争端解决中的证据规则与先例制度研究——以DS362案为例

知识产权已成为各国抢占制高点、增强竞争力的利器，而利用知识产权国际争端解决机制实现对本国利益的保护也成为发达国家有效手段之一。2009年3月，WTO争端解决机构审议通过了“中国-影响知识产权的保护与执行的相关措施案”的专家组报告。尽管美国的大部分主张被驳回，但有必要对国际知识产权争端解决程序中的证据规则、先例制度等相关问题进行分析与总结，为研究应对策略、提高应对能力提供借鉴。