Contextual information management: An example of independent-checking in the review of laboratory-based bloodstain pattern analysis

This article describes a New Zealand forensic agency's contextual information management protocol for bloodstain pattern evidence examined in the laboratory. In an effort to create a protocol that would have minimal impact on current work-flow, while still effectively removing task-irrelevant contextual information, the protocol was designed following an in-depth consultation with management and forensic staff. The resulting design was for a protocol of independent-checking (i.e. blind peer-review) where the checker's interpretation of the evidence is conducted in the absence of case information and the original examiner's notes or interpretation(s). At the conclusion of a ten-case trial period, there was widespread agreement that the protocol had minimal impact on the number of people required, the cost, or the time to complete an item examination. The agency is now looking to adopt the protocol into standard operating procedures and in some cases the protocol has been extended to cover other laboratory-based examinations (e.g. fabric damage, shoeprint examination, and physical fits). The protocol developed during this trial provides a useful example for agencies seeking to adopt contextual information management into their workflow.     

眼损伤法医学错误鉴定分析（附2例分析）

眼损伤法医学鉴定是法医临床学鉴定中的难点和研究热点,也是最容易出现错误鉴定的地方。本文针从两例错误鉴定入手,分析错误鉴定主要原因,一是鉴定人未关注病历材料中显示的重要信息,对病历材料中反映的既往病史、损伤动态发展及检查结果未予重视：二是鉴定人不具备眼损伤检查的基本技能,过度依赖外部信息。三是鉴定人不具备眼损伤的基础专业知识．对各类信息缺乏准确认识．对常见的眼损伤转归及预后不掌握。因此,结合上述问题,笔者建议鉴定人应当采取以下对策阻止或减少错误鉴定的发生,（1）完整审阅病历资料、影像学资料是基础;（4）实施细致、完善检查是关键;（3）准确把握鉴定标准是核心;（4）加强鉴定人专业技能和法律意识的提高是根本。     

2012年法医临床学研究进展

本文以中国知网为网络搜索平台,综述了2012年法医临床学研究领域的最新进展,主要包括伤残鉴定、损伤程度鉴定和医疗纠纷鉴定等。上述内容代表了法医临床学研究领域的最高研究水平。     

Estimating drop-out probabilities of STR alleles accounting for stutters,detection threshold truncation and degradation

Allelic drop-out continues to be a challenge to forensic geneticists when interpreting crime scene evidence and calculating the evidential weight. Methods exist for estimating the probability of allelic drop-out, where the most promising methods use the signal intensities as input for quantifying the drop-out probability. Using data from real crime cases, we demonstrate that taking degradation of the biological material and truncation of the data due to a detection threshold into account is superior to previous approaches. An additional correction for stuttering effects showed limited improvement.     

Analysis of 15 autosomal STR loci in the population of the State of Acre,Brazilian Amazonia

Acre was the last state of Brazil to be inhabited by non-indigenous individuals. The aim of this study was to calculate the allele frequencies of 15 STR loci in 503 unrelated individuals living in Acre, as well as to estimate statistical parameters of forensic interest. The Hardy–Weinberg equilibrium test performed in the overall sample, as well as population comparisons between sub-samples from the five regions in Acre did not reveal the presence of population substructure. This is the first report of STR data in this population and the results showed that a single database is suitable for all the regions analyzed.     

The Ge.F.I. DNA Proficiency Test: Year-one experience

The Ge.F.I. (the Italian Speaking Working Group of ISFG) has launched the first DNA Proficiency Test in 2012. The aim is to increase the external quality controls in forensic genetics in Italy and to drive to the standardizations of methods within the laboratories. Reference and mixed stains typing as well as statistical exercises were proposed and 26 laboratories submitted results.     

Soil sample metagenome NGS data management for forensic investigation

Soil analysis is a valuable resource in forensic investigation. Classical forensic soil analysis involves examination of its physical characteristics and chemical composition, such as soil type, colour, particle size, shape, pH, elemental, mineral and organic content. However the limited variability of these parameters is not always allowing adequate discrimination between soil samples. As soil supports extreme diversity of microorganisms and eukaryotic communities, microbiological approaches have been proposed. Several molecular approaches for microbial DNA profiling are available; however there is a lack of published data of implementation of the next generation sequencing (NGS) approaches for forensic soil analysis.The aim of the current study was elaboration of criteria for soil metagenome data management and database searching. We used our previously sequenced collection of 11 samples collected from different environments (forests, fields, grasslands, urban park) with different flora. The single sample collection includes 9 soil samples per one sampling area (30 m × 30 m) spaced by 15 m. In the current study we concentrated mainly on 18S rRNA gene V2-V3 region for fungi however SSU rRNA region for arbuscular mycorrhizal (AMF) fungi and V2-V3 hypervariable region of 16S rRNA gene for bacterial communities were taken into account. The sequencing was performed by Roche/454 platform. For data analysis OTU based approach on mothur software and NCBI BLASTN search were used. NCBI BLASTN analysis revealed altogether 2983 AMF matches and 8997 18S matches as well as 25477 OTUs (16S) were determined. Several data filtration approaches were used for data management. We found that 18S marker results could be used to create and run a filtered database that is computationally much more efficient and flexible. Our results have broad impact; however more samples have to be analysed, additional studies performed and cooperation between soil scientists and forensic scientists is required to be able to implement these novel techniques into the routine forensic practice.     

A 1-year time course study of human RNA degradation in body fluids under dry and humid environmental conditions

Blood, saliva and semen are some of the forensically most relevant biological stains found at crime scenes. mRNA profiling is a reliable approach for the identification of the origin of an evidentiary trace. A stable set of markers and the knowledge about the effects of RNA degradation under different environmental conditions is necessary for the determination of an unknown biological stain. The aim of this work was to compare RNA degradation for human blood, semen and saliva at three different concentrations during a 1-year time period and exposed to dry and humid conditions. Also, this study addressed the question whether there are relevant differences in the efficiency of two RNA extraction methods.     

Multiplex high resolution melt (HRM) messenger RNA profiling assays for body fluid identification

Traditional body fluid identification methods use a variety of technologically diverse techniques that do not permit the identification of all body fluids. Definitive identification of the biological material present can be crucial to a fuller understanding of the circumstances pertaining to a crime. Thus definitive molecular based strategies for the conclusive identification of forensically relevant biological fluids need to be developed. Messenger (mRNA) profiling is an example of such a molecular based approach.Current mRNA body fluid identification assays typically involve either capillary electrophoresis (CE) or quantitative RT-PCR (qRT-PCR) platforms, each with its own limitations. Both platforms require the use of expensive fluorescently labeled primers or probes. CE-based assays require separate amplification and detection steps thus increasing the time required for analysis. For qRT-PCR assays, only 3 or 4 markers can be included in a single reaction since each requires a different fluorescent dye. To simplify mRNA profiling assays and to reduce the time and cost of analysis, we have developed multiplex high resolution melt (HRM) assays that provide an identification of all forensically relevant biological fluids and tissues.