Establishing phone-pair co-usage by comparing mobility patterns

In forensic investigations it is often of value to establish whether two phones were used by the same person during a given time period. We present a method that uses time and location of cell tower registrations of mobile phones to assess the strength of evidence that any pair of phones were used by the same person. The method is transparent as it uses logistic regression to discriminate between the hypotheses of same and different user, and a standard kernel density estimation to quantify the weight of evidence in terms of a likelihood ratio. We further add to previous theoretical work by training and validating our method on real world data, paving the way for application in practice. The method shows good performance under different modeling choices and robustness under lower quantity or quality of data. We discuss practical usage in court.     

Combined Statistical Analyses of Forensic Evidence in Sexual Assault: A Case Report and Brief Review of the Literature

DNA analysis has been widely used in the forensic field in order to contribute to identifying the perpetrator of a crime. Forensic investigation in sexual assaults usually focuses on locating and identifying biological fluids, followed by DNA analysis. The identification of certain compounds present in condoms can be useful to reconstruct the occurred event, especially in cases of sexual assaults where the DNA analysis did not show the presence of a male profile and where RNA analysis did not show the presence of sperm markers. Herein we describe the case of a woman reporting to be victim of sexual assault, who was not able to provide accurate information concerning the dynamics of the event; she remembered only forced penile–vaginal penetration by a single perpetrator. We performed short tandem repeat (STR) analyses and mRNA typing for forensic genetics testing on vaginal and rectal swabs collected on the victim, and Fourier-transform infrared spectroscopy (FTIR) followed by chromatographic analyses for the detection of condom compounds on the same swabs. The STR analysis showed only the victim’s genetic profile, and RNA analysis showed only the presence of vaginal and skin markers. In this situation, the identification of condom compounds residues on vaginal swabs became important as it complemented other collected evidences allowing the Court to reconstruct the events. A proposal of likelihood ratio (LR) calculation for the assessment of the weight of evidence in this case is described.     

Revisiting the matrilineal lineages and hypoxic adaptation of highland Tibetans

The mitochondrial DNA (mtDNA) plays a vital role in forensic, anthropological, biogeographical and genealogical studies. In the present study, we sequenced 59 mitochondrial genomes of Tibetan individuals settling in Muli Tibetan Autonomous County of Sichuan Province using the Precision ID mtDNA Whole Genome Panel and Ion S5 XL system. Meanwhile, 192 published complete mitogenomes from five Tibetan populations were included for further analysis. All 251 investigated Tibetan participants were assigned to 98 unique subclades pertained to the macrohaplogroups M and N, and 17 subhaplogroups were considered as major haplogroups of Tibetans since these subhaplogroups accounted for considerably high frequencies in randomly selected Tibetans. It was noteworthy that M9a1a1c1b1a was the predominant subhaplogroup in the Tibetans collectively. Furthermore, the nonsynonymous substitutions and synonymous substitutions ratios (N/S) of Tibetans, Tibetan highlanders (Monpas, Lhobas, Dengs and Sherpas), non-Tibetan highlanders and general populations were estimated to evaluate the potential selective constraints. The N/S ratio in the Tibetan groups (0.503) is higher than that in Tibetan highlanders (0.465), non-Tibetan highlanders (0.430) and general populations (0.415). The distributions of N/S ratio in 13 protein-coding genes revealed that significant differences were existed in COX2, ATP8 genes, which likely contributed to hypoxic adaptation.     

中国县区级出生性别比治理的社会政策系统协调性分析

本研究采用政策系统协调性分析框架,对中国县区级出生性别比治理的社会政策系统协调性进行分析,揭示了目前县区级出生性别比治理相关社会政策系统中所存在的不协调问题。其中,系统内部不协调主要包括政策主体内部的不协调、政策客体内部的不协调以及主体和客体之间的不协调;系统外部不协调主要包括本社会政策系统与其他政策系统之间的不协调,以及本政策系统与环境之间的不协调。     

Reflections on variability in the blood–breath ratio of ethanol and its importance when evidential breath-alcohol instruments are used in law enforcement

Variability in the blood–breath ratio (BBR) of alcohol is important, because it relates a measurement of the blood-alcohol concentration (BAC) with the co-existing breath-alcohol concentration (BrAC). The BBR is also used to establish the statutory BrAC limit for driving from the existing statutory BAC limits in different countries. The in-vivo BBR depends on a host of analytical, sampling and physiological factors, including subject demographics, time after end of drinking (rising or falling BAC), the nature of the blood draw (whether venous or arterial) and the subject’s breathing pattern prior to exhalation into the breath analyzer. The results from a controlled drinking study involving healthy volunteers (85 men and 15 women) from three ethnic groups (Caucasians, Hispanics and African Americans) were used to evaluate various factors influencing the BBR. Ethanol in breath was determined with a quantitative infrared analyzer (Intoxilyzer 8000) and BAC was determined by headspace gas chromatography (HS-GC). The BAC and BrAC were highly correlated (r = 0.948) and the BBR in the post-absorptive state was 2 382 ± 119 (mean ± SD). The BBR did not depend on gender (female: 2 396 ± 101 and male: 2 380 ± 123, P > 0.05) nor on racial group (Caucasians 2 398 ± 124, African Americans 2 344 ± 119 and Hispanics 2 364 ± 104, P > 0.05). The BBR was lower in subjects with higher breath- and body-temperatures (P < 0.05) and it also decreased with longer exhalation times into the breath-analyzer (P < 0.001). In the post-absorptive state, none of the 100 subjects had a BBR of less than 2 100:1.     

What’s Sex (Composition) Got to Do with It? The Importance of Sex Composition of Gangs for Female and Male Members’ Offending and Victimization

Sex composition of groups has been theorized in organizational sociology and found in prior work to structure female and male members’ behaviors and experiences. Peer group and gang literature similarly finds that the sex gap in offending varies across groups of differing sex ratios. Drawing on this and other research linking gang membership, offending, and victimization, we examine whether sex composition of gangs is linked to sex differences in offending in this sample, further assess whether sex composition similarly structures females’ and males’ victimization experiences, and if so, why. Self-report data from gang members in a multi-site, longitudinal study of 3,820 youths are employed. Results support previous findings about variations in member delinquency by both sex and sex composition of the gang and also indicate parallel variations in members’ victimization. These results are further considered within the context of facilitating effects such as gender dynamics, gang characteristics, and normative orientation.     

中国农村人口出生性别比发展水平分析

出生性别比是人口性别年龄结构发展变化的自然基础。出生性别比失衡是中国人口问题面临的一个复杂、实际的深层次问题。依据历次人口普查数据显示,由于农村较低的生产力水平和现行的计划生育政策,人口出生性别比偏高的趋势仍未明显缓解。传统的生育文化是导致农村出生性别比居高不下的根本原因,宽松的计划生育政策及执行是出生性别比偏高的关键因素,先进医疗技术的滥用甚至违法使用更加速了出生性别比的失衡状态,另外农村社会保障薄弱以及计划生育户的奖励幅度过低也是出生性别比偏高的主要原因。     

祖孙关系鉴定中引入不同参考个体的系统效能分析

目的 对不同祖孙关系鉴定组合进行效能分析,为选择合适的参考个体和STR检测体系进行祖孙关系鉴定提供参考.方法 构建常见的9种二个体、三个体、四个体祖孙鉴定组合场景,每种组合分别模拟10000个真家系和假家系,计算每种组合在15～65个STR基因座检测体系的祖孙关系指数,评估不同阈值下的系统效能.结果 引入参考个体的祖孙...     

Variability in the Blood/Breath Alcohol Ratio and Implications for Evidentiary Purposes

The breath analyzer is an indispensable tool for identifying alcohol levels among drivers. While numerous studies have shown high correlations between blood and breath alcohol concentrations, most are limited by the study design. This study seeks to assess this relationship by minimizing potential measurement bias, document time from alcohol consumption to testing, and adjusting for potential confounders. A blinded study was performed using conditions closely resembling those in the field. The Draeger 7110 MKIII IL breath analyzer was used to assess breath alcohol concentrations (BrAC). Participants were 61 healthy volunteers aged 21–37 years with body mass index ≤30 and no history of alcoholism. A total of 242 valid blood/breath tests were performed in four test sets. The study results showed a high correlation coefficient between BrAC and blood alcohol concentration (BAC) levels (r = 0.983) with high sensitivity (97%) and specificity (93%). This strong association between the breath analyzer and BAC persisted even after adjustment for various stages of alcohol absorption. These results illustrate the high diagnostic sensitivity of the breath analyzer in field‐tested conditions.     

民生风险理论与食品安全的刑法规制

民生风险是指包括生产、生活在内的社会活动对民生可能造成危害的风险,规制民生风险的刑法就叫做民生刑法。食品安全问题是民生风险的一项重要内容,包括食品生产制造(包括储存、运输等所有"食品入口"之前的环节)时难以避免的"工艺风险"、对食材配料定位不断变化的"认识风险"及生产和配料中的"人为错误"。其中"人为错误"是行为人能够或应该认识到并加以控制的对食品安全的侵害。而工艺风险和认识风险因难于预测、不易避免,其刑法适用尚待进一步探究,而不能简单地引入"风险"观念,通过加大打击力度、增设新罪来解决。民生风险和民生刑法的概念就避免了"风险"理论对刑法基本底线的违背,较好地把握了理论节度,成为规制食品安全较为合适的刑法指导性理念。