Personal Identification by Morphometric Analyses of Intra‐Oral Radiographs of Unrestored Teeth*

Abstract: The aim of this study was to work out a biometric method for personal identification by comparing simulated antemortem and postmortem digital radiographs of unrestored teeth. Intra‐oral radiographs of the inferior right first molar, without restorations, were acquired at two different times in 70 subjects using a standardized technique followed by a morphometric analysis. The program automatically supplied values of the absolute distances, relative distances, shape factors, moments, perimeter values, and the areas of the triangles, which were obtained by joining key reference points. The values for the homologous samples were compared with the heterologous samples. Statistical analysis was then carried out, resulting in a section point value of 0.9992. Higher correlation coefficients indicate positive identification, with less than 2% risk of false positives, and approximately 3% of false negatives. We have also tested the method on dental records from 30 patients in order to demonstrate the specificity and sensitivity of the system.     

Post-mortem Iris Decomposition and its Dynamics in Morgue Conditions

With increasing interest in employing iris biometrics as a forensic tool for identification by investigation authorities, there is a need for a thorough examination and understanding of postmortem decomposition processes that take place within the human eyeball, especially the iris. This can prove useful for fast and accurate matching of antemortem with postmortem data acquired at crime scenes or mass casualties, as well as for ensuring correct dispatching of bodies from the incident scene to a mortuary or funeral homes. Following these needs of forensic community, this paper offers an analysis of the coarse effects of eyeball decay done from a perspective of automatic iris recognition. We analyze postmortem iris images acquired for a subject with a very long postmortem observation time horizon (34 days), in both visible light and near-infrared light (860 nm), as the latter wavelength is used in commercial iris recognition systems. Conclusions and suggestions are provided that may aid forensic examiners in successfully utilizing iris patterns in postmortem identification of deceased subjects. Initial guidelines regarding the imaging process, types of illumination, and resolution are also given, together with expectations with respect to the iris features decomposition rates. Visible iris features possible for human, expert-based matching persists even up to 407 h postmortem, and near-infrared illumination is suggested for better mitigation of corneal opacity while imaging cadaver eyes (Post-mortem iris decomposition and its dynamics in morgue conditions. ArXiv pre-print, 2019).     

The Effect of Decomposition on the Efficacy of Biometrics for Positive Identification

Biometrics, unique measurable physiological and behavioral characteristics, are used to identify individuals in a variety of scenarios, including forensic investigations. However, data on the longevity of these indicators are incomplete. This study demonstrated that iris and fingerprint biometric data can be obtained up to four days postmortem in warmer seasons and 50 + days in the winter. It has been generally believed, but never studied, that iris recognition is only obtainable within the first 24 hours after death. However, this study showed that they remain viable for longer (2–34 days) depending upon the environmental conditions. Temperature, precipitation, insects, and scavenger activity were the primary factors affecting the retention of biometrics in decomposing human remains. While this study is an initial step in determining the utility of physiological biometrics across postmortem time, biometric research has the potential to make important contributions to human identification and the law enforcement, military, and medicolegal communities.     

虹膜人工特征选择和标注方法的初步研究

目的本文主要研究基于虹膜图像的人工特征选择和标注方法,探寻虹膜人工鉴定研究方向,探讨虹膜技术作为一种新的刑事技术在诉讼中应用的可行性。方法首先,作者结合眼解剖学与虹膜基础理论,对虹膜特征进行了粗分类,分为五大类型:放射状沟线、向心沟、卷缩轮、隐窝和色素点;其次,作者结合已有的虹膜算法和图像处理方法对虹膜图像特征的提取和分析方法进行研究;最后,通过专用软件辅助,对虹膜图像进行区域切割、归一化、特征定位和标记、特征信息提取等系列处理。结果初步实现了两张虹膜图像在同一尺度下的人工特征选取和标注。结论本文研究的虹膜人工特征选择和标注方法,是虹膜识别技术在检验鉴定领域应用的初步探索,为后续虹膜人工比对鉴定的深入研究奠定基础。     

The genetics of eye colours in an Italian population measured with an objective method for eye colour quantification

Brown and blue eye colours are primarily explained by the single nucleotide polymorphism (SNP) HERC2 rs12913832. However, the genetics of eye colours that appear to be neither blue nor brown are not well understood. In this study, 230 unrelated Italian individuals were typed for 32 SNP loci in pigmentary genes. High resolution digital images of the participants’ eyes were taken and the iris region was successfully extracted with the use of the custom designed software Digital Iris Analysis Tool (DIAT) from 218 of the 230 (95%) images. The software counted the numbers of blue and brown pixels in the iris region and calculated a Pixel Index of the Eye (PIE-score) that described the eye colours quantitatively. The PIE-score ranged from −1 to 1 (brown to blue). We investigated the association of the PIE-scores extracted from the eye images with the genotypes of the 32 pigmentary SNPs. We observed a statistically significant association between the PIE-scores and the SNP loci rs12913832, rs4778241, rs7495174 in the HERC2/OCA2 region and the locus rs16891982 in SLC45A2.     

An Introduction to Biometrics and Large Scale Civilian Identification

This paper introduces the reader to biometrics and explains how modern biometric technology is used for verification and identification of individuals. It begins by defining the specialist terms used by the biometric industry. It then goes on to consider the difficulties of using biometric technologies in large-scale civilian environments such as National Identity schemes. The paper concentrates on the practical difficulties of accuracy and scaling and considers some fundamental limitations. After establishing that such large scale schemes are difficult to implement, it reflects on how biometric technologies have been adapted and augmented to cope with these challenging situations. The paper concludes by looking at the likely future of such schemes and the likely advances in biometric technology.     

目击证人错误记忆的影响因素研究综述

目击证人对犯罪嫌疑人辨认的结果是定案的重要依据,但目击证人的错误记忆产生的不当陈述又是案件错判的最常见原因,提高目击证人辨认的准确性对于惩罚犯罪和保障公民的权利至关重要。目击证人受外界环境、主观心理等多方面的作用,形成错误记忆,严重影响辨认的准确性。因此,应当借鉴认知心理学对错误记忆的研究方法,抑制错误记忆对目击证人的影响因素,提高目击证人辨认结果的准确性。     

Pig-mentation: postmortem iris color change in the eyes of Sus scrofa

Experienced forensic pathologists and examiners may be familiar with the phenomenon of postmortem iris color change; however, only Knight, Simpson's forensic medicine, Arnold, London, 1997; Ref. 1 and Saukko and Knight, Knight's forensic pathology, 3rd ed., Arnold, London, 2004; Ref. 2 have referred to it in the literature, and to date, there have been no published scientific research studies on this taphonomic artifact. A controlled experiment was conducted of postmortem changes to isolated Sus scrofa eyes. The eyes (n = 137) were separated into three groups and each sample was observed for 3-day postmortem at a different temperature. In addition, a Sus scrofa head was obtained to observe postmortem changes of eyes in situ. All isolated blue eyes in the experiment, at room temperature and higher, changed to brown/black within 48 h. The in situ blue eye, at room temperature, turned brown/black within 72 h. If iris color consistently changes postmortem in humans, then this taphonomic artifact must be incorporated into victim identification protocol, including disaster victim identification software, and autopsy reports to prevent inaccurate victim identification and inappropriate exclusion from the identification process.     

The Effect of Image Alterations on Identification Using Palmar Flexion Creases

Palmprints are identified using matching of minutia points, which can be time consuming for fingerprint experts and in database searches. This article analyzes the operational characteristics of a palmar flexion crease (PFC) identification software tool, using a dataset of 10 replicates of 100 palms, where the user can label and match palmar line features. Results show that 100 palmprint images modified 10 times each using rotation, translation, and additive noise, mimicking some of the characteristics found in crime scene palmar marks, can be identified with a 99.2% genuine acceptance rate and 0% false acceptance rate when labeled within 3.5 mm of the PFC. Partial palmprint images can also be identified using the same method to filter the dataset prior to traditional matching, while maintaining an effective genuine acceptance rate. The work shows that identification using PFCs can improve palmprint identification through integration with existing systems, and through dedicated palmprint identification applications.     

Legal and ethical considerations of biometric identity card: Case for Mauritius

The highly connected nature of the current era has raised the need for more secure systems, and hence the demand for biometric-based authentication methods. In 2013, the Mauritian Government invested massively in the collection of data, and implementation of the national biometric identity card scheme. The latter has suffered a number of contestations among the population, and several cases were consequently filed at the Supreme Court of Mauritius to oppose the use of this biometric card. The main concern was the collection of biometric data which posed threats to the privacy of individuals. Additionally, the collection and retention of biometric data lead to security issues. In this paper, the challenges with respect to the usage of the biometric card are analysed. The laws governing data protection are discussed, together with the legal framework used for data collection and retention. Following the court decisions, several amendments have been made to the existing laws in order to cater for the usage of biometric data for the public interest. Finally, recommendations are made with regards to a legal framework which will enhance the security of biometric data, and eventually encouraging public acceptance of this biometric identification system.     

大数据背景下个人生物识别信息安全的法律规制

个人生物识别信息具有个人数据的唯一性、程序识别性、可复制性、损害的不可逆性及信息的关联性等特征。在大数据背景下,个人生物识别信息的广泛应用会带来严重的生物信息安全风险,其滥用可造成隐私权、平等权和财产权等权益受到侵犯,需要立法进行全方位规制。我国目前个人生物信息的相关立法存在总体位阶较低且内容分散、保护范围狭窄、权利义务边界不清、法律责任不明晰等缺陷,应当采取渐进式专门立法的思路,完善现有相关部门法关于个人生物信息的规制内容,构建层次分明、内外协调的个人生物识别信息安全保护的法律体系。     

Fingerprint Change: Not Visible,But Tangible

Hand–foot syndrome, a chemotherapy‐induced cutaneous toxicity, can cause an alteration in fingerprints causing a setback for cancer patients due to the occurrence of false rejections. A colon cancer patient was fingerprinted after not having been able to use fingerprint recognition devices after 6 months of adjuvant chemotherapy. The fingerprint images were digitally processed to improve fingerprint definition without altering the papillary design. No evidence of skin toxicity was present. Two months later, the situation returned to normal. The fingerprint evaluation conducted on 15 identification points highlighted the quantitative and qualitative fingerprint alteration details detected after the end of chemotherapy and 2 months later. Fingerprint alteration during chemotherapy has been reported, but to our knowledge, this particular case is the first ever reported without evident clinical signs. Alternative fingerprint identification methods as well as improved biometric identification systems are needed in case of unexpected situations.     

Roadside detection of impairment under the influence of ketamine--evaluation of ketamine impairment symptoms with reference to its concentration in oral fluid and urine

Although there are many roadside testing devices available for the screening of abused drugs, none of them can be used for the detection of ketamine, a popular abused drug in Hong Kong. In connection to local drug driving legislation, effective roadside detection of ketamine in suspected drug-impaired drivers has to be established. According to the drug evaluation and classification program (DEC), ketamine is classified in the phencyclidine (PCP) category. However, no study has been performed regarding the signs and symptoms exhibited by users under the influence of ketamine. In a study to develop a protocol for effective roadside detection of drug-impaired drivers, 62 volunteers exiting from discos were assessed using field impairment tests (FIT) that included measurements of three vital signs (i.e. body temperature, pulse rate and blood pressure), three eye examinations [pupil size, lack of convergence (LOC) and horizontal gaze nystagmus (HGN)] and four divided attention tests (Romberg, one-leg stand, finger-to-nose and walk-and-turn tests). Subsequent laboratory analysis of oral fluid and urine samples from the participants revealed the presence of common abused drugs in both the urine and oral fluid samples of 55 subjects. The remaining 7 subjects with no drug in their oral fluid samples were used as drug-free subjects. In addition, 10 volunteers from the laboratory who were regarded as drug-free subjects were also assessed using the same FIT. Among the 62 volunteers, 39 of them were detected with ketamine in their oral fluid. Of these ketamine users, 21 of them (54%) with only ketamine found in their oral fluid samples while the rest (18 subjects) of them had other drugs (i.e. MA, MDMA, benzodiazepines and/or THC) in addition to ketamine. Of the 21 ketamine-only users, 15 of them (71%) were successfully identified by FIT. It was found that when salivary ketamine concentrations were greater than 300 ng/mL, signs of impairment became evident, with over 90% detection rate using the FIT. By comparing the FIT observations on the 21 ketamine-only users with the drug-free subjects, the typical signs and symptoms observable for subjects under the influence of ketamine included LOC, HGN, elevated pulse rate and in general, failing the divided attention tests, especially the walk-and-turn and one-leg stand.     

The application of visible wavelength reflectance hyperspectral imaging for the detection and identification of blood stains

Current methods of detection and identification of blood stains rely largely on visual examination followed by presumptive tests such as Kastle–Meyer, Leuco-malachite green or luminol. Although these tests are useful, they can produce false positives and can also have a negative impact on subsequent DNA tests. A novel application of visible wavelength reflectance hyperspectral imaging has been used for the detection and positive identification of blood stains in a non contact and non destructive manner on a range of coloured substrates. The identification of blood staining was based on the unique visible absorption spectrum of haemoglobin between 400 and 500 nm. Images illustrating successful discrimination of blood stains from nine red substances are included. It has also been possible to distinguish between blood and approximately 40 other reddish stains. The technique was also successfully used to detect latent blood stains deposited on white filter paper at dilutions of up to 1 in 512 folds and on red tissue at dilutions of up to 1 in 32 folds. Finally, in a blind trial, the method successfully detected and identified a total of 9 blood stains on a red T-shirt.     

Contextual information renders experts vulnerable to making erroneous identifications

We investigated whether experts can objectively focus on feature information in fingerprints without being misled by extraneous information, such as context. We took fingerprints that have previously been examined and assessed by latent print experts to make positive identification of suspects. Then we presented these same fingerprints again, to the same experts, but gave a context that suggested that they were a no-match, and hence the suspects could not be identified. Within this new context, most of the fingerprint experts made different judgements, thus contradicting their own previous identification decisions. Cognitive aspects involved in biometric identification can explain why experts are vulnerable to make erroneous identifications.     

Children's identification of unfamiliar voices on both target-present and target-absent lineups

ABSTRACT

A robust finding from the eyewitness literature is that children are as accurate as adults on target-present lineups from the age of five years, whereas they continue to make an erroneous false positive identification from a target-absent lineup up until around fourteen years of age (Pozzulo, J. D., & Lindsay, R. C. L. (1998). Identification accuracy of children versus adults: a meta-analysis. Law and Human Behavior, 22(5), 549–570). The current study explores whether the same pattern occurs when voices are used instead of faces. A total of 334 participants from six age groups (6–7-year-olds, 8–9-year-olds, 10–11-year-olds, 12–13-year-olds, 14–15-year-olds and adults) listened to a 30 second audio clip of an unfamiliar voice and were then presented with either a six person target-present or target-absent voice lineup. Overall, participants were more accurate with target-present than target-absent lineups. Moreover, performance on target-present lineups showed adult-like levels of attainment by 8–9 years of age. In contrast, performance on target-absent lineups was extremely poor, with all age groups tending to make a false identification. Confidence was higher when participants made correct rather than incorrect decisions for both types of lineup and this did not change with increasing age. Given these results, both child and adult earwitness evidence needs to be treated with considerable caution.     

Having yes,using no? About the new legal regime for biometric data

The rise of biometric data use in personal consumer objects and governmental (surveillance) applications is irreversible. This article analyses the latest attempt by the General Data Protection Regulation (EU) 2016/679 and the Directive (EU) 2016/680 to regulate biometric data use in the European Union. We argue that the new Regulation fails to provide clear rules and protection which is much needed out of respect of fundamental rights and freedoms by making an artificial distinction between various categories of biometric data. This distinction neglects the case law of the European Court of Human Rights and serves the interests of large (governmental) databases. While we support regulating the use and the general prohibition in the GDPR of using biometric data for identification, we regret this limited subjective and use based approach. We argue that the collection, storage and retention of biometric images in databases should be tackled (objective approach). We further argue that based on the distinctions made in the GDPR, several categories of personal data relating to physical, physiological or behavioural characteristics are made to which different regimes apply. Member States are left to adopt or modify their more specific national rules which are eagerly awaited. We contend that the complex legal framework risks posing headaches to bona fide companies deploying biometric data for multifactor authentication and that the new legal regime is not reaching its goal of finding a balance between the free movement of such data and protecting citizens. Law enforcement authorities also need clear guidance. It is questioned whether Directive (EU) 2016/680 provides this.     

Children's eyewitness identification performance: Effects of a Not Sure response option and accuracy motivation

Purpose. Children who witness crimes are sometimes asked to view a photospread lineup to see if they can identify the culprit. Here, we examined the effectiveness of two manipulations designed to assist in overcoming the tendency of child eyewitnesses to choose from lineups, a tendency that manifests in false identifications from target‐absent lineups. Methods. Children aged around 12 years (N = 432) were randomly assigned to control, Not Sure, or accuracy motivation conditions in order to examine both target‐absent and ‐present identification test performance across multiple sets of stimulus materials. Results. The Not Sure option did not affect false alarms or hit rates, but the combination of accuracy motivating conditions and the Not Sure option reduced guessing, with overall rates of false identifications falling by 12.2%. The latter effect was much stronger under some stimulus conditions but not detectable under others, indicating that the manipulations could improve but not impair performance. While there were beneficial effects at the group level, the manipulation did not produce a general change in individual children's decision strategies. Conclusions. Eyewitness identification test manipulations that reliably reduce false alarms, without lowering hits, by child witnesses have not yet been identified. Here, we showed how a simple‐to‐implement accuracy motivation manipulation reduces false alarms under some conditions, while also highlighting the importance of evaluating the efficacy of interventions across varied encoding and test conditions. However, developing a procedure that can produce a generalized improvement in decision making at the individual level remains a major challenge for eyewitness researchers.     

Multimodal biometrics for identity documents (MBioID)

The MBioID initiative has been set up to address the following germane question: What and how biometric technologies could be deployed in identity documents in the foreseeable future? This research effort proposes to look at current and future practices and systems of establishing and using biometric identity documents (IDs) and evaluate their effectiveness in large-scale developments. The first objective of the MBioID project is to present a review document establishing the current state-of-the-art related to the use of multimodal biometrics in an IDs application. This research report gives the main definitions, properties and the framework of use related to biometrics, an overview of the main standards developed in the biometric industry and standardisation organisations to ensure interoperability, as well as some of the legal framework and the issues associated to biometrics such as privacy and personal data protection. The state-of-the-art in terms of technological development is also summarised for a range of single biometric modalities (2D and 3D face, fingerprint, iris, on-line signature and speech), chosen according to ICAO recommendations and availabilities, and for various multimodal approaches. This paper gives a summary of the main elements of that report. The second objective of the MBioID project is to propose relevant acquisition and evaluation protocols for a large-scale deployment of biometric IDs. Combined with the protocols, a multimodal database will be acquired in a realistic way, in order to be as close as possible to a real biometric IDs deployment. In this paper, the issues and solutions related to the acquisition setup are briefly presented.