On the meaning of the likelihood ratio: Is a large number always an indication of strength of evidence?

There is general lack of awareness that high LR based on complex propositions e.g. three contributors, does not necessarily translate into probative evidence against a suspect. In some cases there is an increased chance of false inclusion of a person of interest. This is an issue for all LR-based models. One way to address this issue is to further evaluate or qualify the estimated LR by a performance test. Based on simulations, this was achieved by non-contributor-testing: replacing the reference profile of interest (typically the suspect's profile), by the profile of a simulated random man. An exact p-value can also be calculated, giving the chance of observing an LR-value exceeding the estimated if the defense hypothesis is true.     

Laser microdissection separation of pure spermatozoa from epithelial cells for short tandem repeat analysis

Short tandem repeat (STR) analysis is a valuable tool in identifying the source of biological stains, particularly from the investigation of sexual assault crimes. Difficulties in analysis arise primarily in the interpretation of mixed genotypes when cell separation of the sexual assailant's sperm from the victim's cells is incomplete. The forensic community continues to seek improvements in cell separation methods from mixtures for DNA typing. The feasibility of applying laser microdissection (LMD) technology to precisely separate sexual assault cell mixtures by visual inspection coupled with laser dissection was assessed through three experiments. First, various histological stains were evaluated for use with LMD and DNA analysis. Second, different DNA isolation methods were evaluated on LMD-collected cells. Finally, STR analysis was performed on LMD-separated sperm cells from mixtures of semen and female buccal epithelial cells. The results indicated (a) hematoxylin/eosin staining performed best in its ability to differentiate sperm and epithelial cells while exhibiting the least negative effect on further downstream analysis; (b) both QIAamp and Lyse-N-Go methods were useful for recovery of DNA from LMD-collected sperm cells; and (c) LMD separation provided clear STR profiles of the male donor with the absence of any additional alleles from the female donor. This report describes an efficient, low-manipulation LMD method for the efficient separation of spermatozoa from two-donor sperm/epithelial cell mixtures.     

Inclusion Probabilities and Dropout

Abstract: Recent discussions on a forensic discussion group highlighted the prevalence of a practice in the application of inclusion probabilities when dropout is possible that is of significant concern. In such cases, there appears to be an unpublished practice of calculation of an inclusion probability only for those loci at which the profile of interest (hereafter the suspect) is fully included among the alleles present in the crime scene sample and to omit those loci at which the suspect has alleles that are not fully represented among the alleles in the mixture. The danger is that this approach may produce apparently strong evidence against a surprisingly large fraction of noncontributors. In this paper, the risk associated with the approach of ignoring loci with discordant alleles is assessed by simulation.     

DIP-STR在不平衡混合DNA样本中的分析研究

当前,DNA检验技术作为打击犯罪的利器,在法医鉴定中发挥着巨大作用。但对于性侵、暴力犯罪等案件中提取的混合DNA样本,尤其是从受害人或嫌疑人的接触物上采集的高度不平衡混合DNA样本,利用常染色体STR检验方法得到的结果通常不是很理想。由于PCR扩增偏倚,从混合样本中检测出痕量DNA分型是一个巨大的挑战,也是当前法医DNA检验的一个难点。近年来的研究显示,利用新型连锁遗传标记DIP-STR,即结合缺失或插入多态性片段DIP(deletion–insertion polymorphisms)和STR的连锁位点,可以用来检测出混合DNA样本中任一性别和细胞起源的微量DNA,甚至在DNA混合比例高达1:1000时,DIP-STR标记的灵敏度、特异性仍旧相对较为理想。因此,DIP-STR标记的分析可以作为常染色体STR检验的有效补充。本文将对DIP-STR在不平衡混合DNA样本分析中的研究背景、方法及其应用前景进行综述。     

当前利用现场指纹进行检验查档中亟待重视的若干问题

当前,必须巩固和加强传统指纹技术在刑侦工作中的特殊作用和地位,理性、客观地认识到新的指纹自动识别技术必须建立在传统指纹技术基础上。刑侦技术人员必须大力提高指纹检验的基本技能和水平,牢固确立指纹检验工作中人的决定因素,改变主观上漠视或轻视犯罪现场保护的现状,努力提高现场指纹的提取破案率。     

Who's Your Daddy?: The Marital Presumption of Legitimacy in the Modern World and its Application to Same‐Sex Couples

Recently, the definition of marriage has been significantly altered. No longer do we find ourselves exclusively in the midst of “traditional marriage” between one man and one woman. Instead, everywhere we experience different kinds of marriages and diverse, nontraditional families. The United States has finally caught up to many advanced democracies in universally recognizing same‐sex marriage through the Supreme Court's decision in Obergefell v. Hodges. However, the next question remains unanswered: what about families of same‐sex couples? This Note explores the nature of same‐sex couples, their families, and in particular, their children. It addresses the issue of the marital presumption of legitimacy and encourages its application to all legally recognized married couples regardless of sexual orientation and biology. Even though prior to Obergefell some states were unwilling to apply the presumption, since the implementation of marriage equality, the next logical step would be to utilize the presumption to ensure that all parents, regardless of gender, are recognized and families are preserved.     

法医尸检工作中常见的职业危害因素及预防措施

法医尸体解剖在解决民事、刑事案件中所涉及的死亡原因、死亡方式等问题中发挥重要作用,法医作为尸体检验工作的承担者,其在尸检过程中自身常面临多种危害因素,本文对法医实践中常见的职业性危害因素以及其可能危害机制进行总结分析,以期提高法医的自我保护意识并引起相关部门的重视.     

DNA数据库比对技术在刑事侦查中运用的合宪性问题

DNA数据库比对技术实质上是基因检测技术和大数据处理技术相结合的产物。DNA数据库比对技术可以精确锁定犯罪嫌疑人,由于其强大的证明能力而被广泛地运用于刑事侦查,各国都积极推动DNA数据库的建立。DNA数据库比对技术在维护了社会安全的同时也对公民基因隐私构成极大威胁。如何在技术的运用和隐私权保障之间做出更好的平衡,是DNA比对技术的合宪性争议的中心。廓清了合宪性问题,我们才可以更好地制定相关法律,消弭合宪性问题,在保障公民隐私权的同时也更好地维护社会安全。     

马钱子中毒生物检材的毛细管电泳法分析

测定马钱子蓄积中毒死者胃内容和肝组织中马钱子碱成分含量。以标准马钱子碱和送检马钱子药材粉末作对照 ,采用毛细管电泳仪在 190～ 6 0 0nm波长 ,扫描分析检材中马钱子碱成分含量。结果表明 :马钱子碱成分在检材中的含量分别为 5 83mg/ 10 0ml、 4 92mg/ 10 0 g和 3 0 7% (w/w )。确认死者的胃内容、肝组织中的高含量马钱子碱而引起的中毒死亡。     

Enclosing the global commons: the convention on biological diversity and green grabbing

‘Green grabs,’ or the expropriation of land or resources for environmental purposes, constitute an important component of the current global land grab explosion. We argue that international environmental institutions are increasingly cultivating the terrain for green grabbing. As sites that circulate and sanction forms of knowledge, establish regulatory devices and programmatic targets, and align and articulate actors with these mechanisms, they structure emergent green market opportunities and practices. Drawing on the idea of primitive accumulation as a continual process, we examine the 10^th Conference of the Parties to the United Nations Convention on Biological Diversity as one such institution.