The survival of oral streptococci on human skin and its implication in bite-mark investigation

Ten-microlitre aliquots of whole saliva applied to human skin were sampled for periods up to 6.25 h. The rate of loss of recoverable bacteria was 45–50% per hour. After 6.25 h, viable oral streptococci could be recovered. The implications for using a “fingerprint” typing method for these bacteria with regard to the identification of bite-marks are discussed.     

血清IgE在药物过敏性休克死亡鉴定中的价值

目的 探讨血清IgE在药物过敏性休克死亡鉴定中的应用价值。方法 采用MEIA法，对17例明确鉴定为药物过敏性休克死亡者(休克组)和16例交通事故死亡者(对照组)的心血进行IgE检测，并对2组IgE检测结果进行统计学分析。结果 休克组IgE水平为(622.49±594.67)U／ml，对照组为(45.04±43.62)U／ml；经t检验，2组显著差异(P＜0.01)。结论 血清IgE水平升高，可作为鉴定药物过敏性休克死亡的依据之一。     

牙齿异常者颌面数字全景片同一认定指标及其编码

目的系统筛选颌面影像法医学同一认定的识别指标，制定全口牙型识别指标编码。方法随机选取620例有牙齿治疗史者、150例牙齿有病变无治疗史者的数字全口牙位曲面体层片进行观测，根据牙齿的生理变异、病理改变和治疗特征筛选全口牙型识别指标，并按设计的编码标准和原则对其全口牙型逐一编码，最后分别统计两组全口牙型的多样性以评估其价值。结果620例牙齿有治疗史者中共有619种全口牙型编码，全口牙型多样性为99．84％；150例牙齿有病变无治疗史者中共有146种全口牙型编码，全口牙型多样性为97．33％。结论选出的全口牙型识别指标对牙齿异常者进行法医学同一认定具有实际应用价值。     

On identification problems requiring linked autosomal markers

This paper considers identification problems based on DNA marker data. The topics we discuss are general, but we will exemplify them in a simple context. There is DNA available from two persons. There is uncertainty about the relationship between the two individuals and a number of hypotheses describing the possible relationship is available. The task is to determine the most likely pedigree. This problem is fairly standard. However, there are some problems that cannot be solved using DNA from independently segregating loci. For example, the likelihoods for (i) grandparent–grandchild, (ii) uncle–niece and (iii) half-sibs coincide for such DNA data and so these relations cannot be distinguished on the basis of markers normally used for forensic identification problems: the likelihood ratio comparing any pair of hypotheses will be unity.Sometimes, but not in the examples we consider, other sources of DNA like mtDNA or sex chromosomes can help to distinguish between such equally likely possibilities. Prior information can likewise be of use. For instance, age information can exclude alternative (i) above and also indicate that alternative (iii) is apriori more likely than alternative (ii).More generally, the above problems can be solved using linked autosomal markers. To study the problem in detail and understand how linkage works in this regard, we derive an explicit formula for a pair of linked markers. The formula extends to independent pairs of linked markers. While this approach adds to the understanding of the problem, more markers are required to obtain satisfactory results and then the Lander–Green algorithm is needed. Simulation experiments are presented based on a range of scenarios and we conclude that useful results can be obtained using available freeware (MERLIN and R).The main message of this paper is that linked autosomal markers deserve greater attention in forensic genetics and that the required laboratory and statistical analyses can be performed based on existing technology and freeware.     

The spectroscopic detection of exogenous material in fingerprints after development with powders and recovery with adhesive lifters

The application of powders to fingerprints has long been established as an effective and reliable method for developing latent fingerprints. The powders adhere to the ridge pattern of the fingerprint only, thus allowing the image to be visualised. Fingerprints developed in situ at a crime scene routinely undergo lifting with specialist tapes to facilitate subsequent laboratory analysis. As with all recovered evidence these samples would be stored in evidence bags to allow secure transit from the scene to the laboratory and also to preserve the chain of evidence. In this paper, the application of Raman spectroscopy for the analysis of exogenous material in latent fingerprints is reported for contaminated fingerprints that had been treated with powders and also subsequently lifted with adhesive tapes. A selection of over the counter (OTC) analgesics were used as samples for the analysis and contaminated fingerprints were deposited on clean glass slides. The application of aluminium or iron based powders to contaminated fingerprints did not interfere with the Raman spectra obtained for the contaminants. In most cases background fluorescence attributed to the sebaceous content of the latent fingerprint was reduced by the application of the powder thus reducing spectral interference. Contaminated fingerprints developed with powders and then lifted with lifting tapes were also examined. The combination of these two techniques did not interfere with the successful analysis of exogenous contaminants by Raman spectroscopy. The lifting process was repeated using hinge lifters. As the hinge lifters exhibited strong Raman bands the spectroscopic analysis was more complex and an increase in the number of exposures to the detector allowed for improved clarification. Raman spectra of developed and lifted fingerprints recorded through evidence bags were obtained and it was found that the detection process was not compromised in any way. Although the application of powders did not interfere with the detection process the time taken to locate the contaminant was increased due to the physical presence of more material within the fingerprint. The presence of interfering Raman bands from lifting tapes is another potential complication. This, however, could be removed by spectral subtraction or by the choice of lifting tapes that have only weak Raman bands.     

Are accurate witnesses more likely to make absolute judgments?

The present study tested the Two-Judgment Theory of Eyewitness Identification Accuracy. Specifically, the extent to which participants were able to engage in an absolute judgment strategy was manipulated by varying the time available to view a lineup. Providing a limited exposure to a lineup should “interrupt” decision making, whereby witnesses can only engage a relative strategy, thus leading to higher false positive responding given a target-absent lineup. Seventy-four adults viewed a 1-minute video that exposed them to an unknown target and subsequently viewed the lineup for a limited (2 s) or an unlimited amount of time. Although false positive rates were similar across conditions, accurate witnesses were more confident than inaccurate witnesses. Confidence was negatively correlated with response latency such that witnesses who took more time to make a decision were less confident in their decisions compared to witnesses who made more rapid decisions. Response latency did not differ for accurate and inaccurate witnesses. Limitations and suggestions for future research on the Two-Judgment Theory are discussed.     

“I Had a Confidence Epiphany!”: Obstacles to Combating Post-Identification Confidence Inflation

Research shows that eyewitnesses often become more confident with their selections from a lineup over time, a problem labeled "confidence inflation." Wells et al. (1998) Law and Human Behavior, 22, 603-647 suggested that eyewitnesses provide a confidence statement immediately following their selection to capture an unadulterated measure of confidence. Three experiments tested the effectiveness of introducing such a statement to combat the effects of confidence inflation on mock-juror judgments. All experiments provided evidence that the attributions participants formed about the eyewitness' confidence inflation differentially impacted their judgments. Although mock-jurors generally discredited eyewitnesses who showed confidence inflation and sometimes lowered probability of guilt ratings for the defendant, a clear exception occurred when mock-jurors attributed the inflation to an epiphany. Use of post-identification confidence statements to decrease the impact of confidence inflation in the courtroom may be insufficient.     

网络民意需重视，更需甄别——以立法引入网络民意为例

网络已经成为民意表达的重要渠道,并深刻影响当代中国的社会生活。在立法中引入网络民意,既能有效引导网络舆论,又能充分扩展立法过程的公众参与。但网络民意是否能真实、客观地反映民意,其本身还需要建立有效的甄别机制。     

World War One Italian and Austrian soldier identification project: DNA results of the first case

We report the results of an attempt to identify the supposed remains of a famous World War I (WWI) Italian soldier who was killed in battle along the Italian front in 1915.Thanks to the availability of offspring from both paternal and maternal lineage Y-STRs and mtDNA were analysed and both showed a clear exclusion scenario: the remains did not belong to the supposed war hero.This is the first effort of identification of the remains of soldiers who perished during World War I within a multidisciplinary project aimed at the retrieval of historical and cultural aspects linked to WWI, and the systematic study of the remains of soldiers and ultimately their identification. This last step involves both Italian and Austrian laboratories.     

DNA条形码技术在法庭科学种属鉴定中的应用

DNA条形码(DNA Barcoding)技术提出10余年,目前已成为国内外食品安全和动物保护等相关领域种属鉴定的新热点,该技术可实现生物样本的快速、准确识别和种属鉴定,为司法实践提供所需的科学证据。本文综述了DNA条形码技术的原理、发展及应用前景。