Systematic approach to the profiling analysis of illicit amphetamine

The use of automated workstations for the study of the origin of illicit produced amphetamine was examined by comparing the precision of peak identification methods of gas chromatographically determined impurities of confiscated amphetamine powders. The identification parameters used were absolute and relative retention times and retention indices. The retention index monitoring proved to be the most precise identification method when intralaboratory repeatability was examined. Preprocessing of gas chromatographic data is needed when automating pattern recognition for rapid screening of the impurities of amphetamine powder. Normalisation of peak areas of the impurity components was studied; scaled data were calculated by dividing peak areas of the chromatogram by the peak area of a selected impurity component of the same chromatogram. The precision of the gas chromatographic method of analysis in a large impurity concentration range was determined by comparing both the normalisation and the quantitation method of analysis with each other. Normalisation was a more precise way to preprocess data than quantitation on the basis of relative standard deviation values for the comparison. In order to get chromatographic data quickly for pattern recognition it is appropriate to prepare amphetamine powders with the same moisture content before making the analysis. The method of drying powders was studied by comparing gas chromatographically produced results of analyses of powders dried at an ambient temperature to those dried using infra-red radiation. The infra-red drying method proved to be suitable for the rapid preparation and analysis of amphetamine powders.     

Human Identification by Oral Prosthesis Analysis with Probability Rates Higher than DNA Analysis

Several techniques are used to perform an appropriate and reliable human identification. Forensic dentistry has achieved great relevance over the past years. The aim of this article is to report the method used for the identification of a male body found in the colliquative stage of putrefaction. The identification of the victim was succeeded confronting the dental findings found in the corpse with the data present on dental records provided by his dentist. The major elements for the identity′s recognition were a metal core and a prosthetic crown that were being fabricated. These elements associated with the dental records were compelling for the elucidation of the case, and a positive body identification was achieved with high levels of probability. In the present case, cadaveric analysis of stomatognathic system structures achieved a probability value higher than DNA identification techniques, emphasizing the importance of forensic dentistry.     

Allele polymorphism of molecular-genetic individualizing systems based on tetranucleotide tandem repeats LPL,vWA and TH01 among the population of Russia

Until recently, data bases on incidence rates of alleles STR (LPL, vWA and THO1 loci) have not been introduced in Russia. To obtain information on the above rates in Russia, a large scale research of distribution of LPL, vWA and Tho1 loci has been performed among a sample of 442 blood-unrelated persons from 57 regions of the Russian Federation to specify basic assessment characteristics of these loci and to raise efficiency of expert use of identifying systems on their base. Relevant parameters (allele frequencies) are presented for each polymorphic locus as well as basic population characteristics of polymorphism in the studied sample of RF population. These results can be used as key parameters for standard probability estimations in assessing the results of molecular-genetic identification.     

Automated gunshot residue particle search and characterization

The main disadvantage to gunshot residue (GSR) particle analysis utilizing scanning electron microscope/energy dispersive X-ray (SEM/EDX) instrumentation has been the excessive operator time required for search and identification. This study uses an automated particle search and characterization program for unattended GSR search and identification. This system allows for automatic matrix search, particle sizing, chemical typing, and spectral aquisition with subsequent storage of data to disk for later operator review and verification. This work describes various aspects of the program, determines appropriate parameters adequate for both unique and characteristic GSR particle identification, and evaluates the reliability of data obtained. Samples are collected via the tape lift method from test-firings of .38, .32, .25, and .22 caliber handguns at time after firing intervals of 0 to 6 h. Unique GSR particles are consistently and correctly identified by this method on tape lift samples taken up to 4 h after firing. False positive results of unique GSR particles are not encountered on control handblank samples. This technique appears to provide the forensic science community with an operator-free method of reliable GSR particle search and an improved analyst-time-per-case ratio.     

Design of the automatic system of processing data on mitochondrial DNA "mDNAbase" sequestration for expert identification of the unidentified bodies under the conditions of mass reception of human remains

The authors consider utilization of software which provides indirect personality identification by establishment of biological kinship using a comparative analysis of nucleotide sequences (NS) of mitochondrial DNA (mtDNA) in unidentified bodies and suspected relatives of these victims. The software supports data bases with information on NS. To secure automatic search there are modes of cross-processing. Results of identification are formed as lists of exclusions and tables with calculated frequencies of mitotypes of identification objects as well as protocols of a comparative analysis of nucleotide position in mtDNA sequences under comparison. The proposed computer approach is a new highly effective tool for identification of personality based on data on mtDNA analysis in conditions of stream information processing under mass reception of unidentified bodies.     

Comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC x GC-TOFMS) for drug screening and confirmation

Comprehensive two-dimensional gas chromatography (GC x GC) is applied to analysis of drug standard mixtures containing 78 drugs of interest in forensic samples. For this study, underivatised drugs were employed. While several of the drugs were not detected at the low concentrations employed in the samples, most could be satisfactorily assigned their first and second dimension retentions in the GC x GC retention plane. For this study, time-of-flight mass spectrometry (TOFMS) detection was used. The enhanced separation possible in GC x GC is demonstrated, and typical linearity and apparatus precision are shown for tramadol, diazepam, olanzapine and desipramine using selected qualifier ions. Mass spectral library search quality for the detection of drugs in a selection of authentic forensic cases, along with retention position in the 2D retention plane, is used to support positive identification of the presence of the drugs. The analysis of 'difficult' drugs paracetamol and phenytoin is shown to produce anomalous chromatographic peak shape in the 2D plane, whereas most drugs gave acceptable peak shapes. The GC x GC technique was applied to screening drugs in forensic samples, with either flame ionisation (FID) or TOFMS detection, and compared favourably with conventional single column GC-MS analysis when tested for diazepam in an authentic forensic study.     

Identification of unknown dead bodies by X-ray image comparison of the skull using the X-ray simulation program FoXSIS

The aim of the study was to improve the objectivity of X-ray image comparison for the identification of unknown dead individuals. CT-data were collected for 30 macerated skulls. An already presented computer program which uses CT data to establish virtual X-ray images was used to obtain X-rays with different beam angulations simulating rotation, dorsal flexion, and ventral flexion. Specific parameters were measured on the simulated images. The frontal sinus reveals the highest variability not only between the individual skulls but also within an individual skull in different positions. The most consistent parameters with respect to different positions were the skull breadth, the biorbital breadth and the bizygomatic breadth. In a blind study, three out of 24 skulls could clearly be identified just by measured distances although the positions were different and unknown to the investigator. The dimensions of the frontal sinus do not correlate with the other skull parameters (analysis of covariance). Based on the presented results, we propose a method that will calculate the probability of identity. The presented results demonstrate that the comparison of X-ray images can be undertaken in an objective way by quantifying the probability of identity even when the comparative images were made under different conditions.     

云南壮族人群15个STR基因座遗传多态性

目的 对600个云南壮族人群15个常染色体短串联重复(short tandem repeat,STR)序列基因座的遗传多态性进行调查,探讨云南壮族群体遗传学特性及在法医学中的应用价值.方法 使用AmpFLSTR? Identifiler? Direct PCR扩增试剂盒对此地区600名壮族无关个体血样DNA进行PCR扩...     

苯二氮卓类新精神活性物质去氯依替唑仑的定性检验方法研究

目的建立苯二氮卓类新精神活性物质去氯依替唑仑的气相色谱-质谱(GC-MS)和超高效液相色谱-四极杆-飞行时间质谱(UPLC-Q-TOF MS)定性检验方法。方法未知样品用甲醇和水提取,取上清液,采用GC-MS和UPLC-Q-TOF MS进行分析。结果经GC-MS检测,保留时间为17.73 min的未知组分的质谱碎片主要特征离子峰有m/z 279,308,239,252,225,77,126。经UPLC-Q-TOF MS检测,保留时间为4.781 min的未知组分的准分子离子峰为309.1173,碰撞诱导解离(CID)模式下二级质谱主要离子有m/z 280.0776,255.0952,240.0719,225.0604,206.0748。经缴获毒品分析科学工作组(Scientific Working Group for the Analysis of Seized Drugs,SWGDRUG)分析谱库检索和文献查询获得的信息资料进行比对,鉴定为去氯依替唑仑。结论该方法具有分析简便、快速的特点,可以用于实际案件的检测。     

The forensic and investigative significance of reverse paternity testing with absent maternal sample

The authors are involved in the extraction of DNA material from calcified tissues, oftentimes teeth, and analysis of such material to assist the investigative process, frequently by confirming the identity of the victim. Biologic or molecular techniques for the purposes of human identification have evolved to allow increasingly discriminating tests for use in criminal and noncriminal death investigations, as well as paternity disputes. The goal of such tests is to either include 2 samples (ie, they are from the same person, or in the case of paternity, they are from related individuals) or exclude 2 samples (ie, they are from different people or from unrelated individuals). Regardless of the system used and when data error has been eliminated, an exclusionary conclusion is irrefutable. The probability of excluding the falsely accused has steadily increased over the years as new methods are developed. Conventional ABO blood typing, for example, has a probability of exclusion (PE) of only 17%. This value increases to 53% with the inclusion of the Rh and MN systems. Additional serological markers can provide a probability of exclusion of greater than 99%. Today, the current method of choice for human identification is the polymerase chain reaction for the amplification of short tandem repeat (STR) multiplexes. This paper discusses the implications of nonpaternity in reverse paternity testing when only paternal DNA is available.     

Validation of the barcoding gene COI for use in forensic genetic species identification

The application of forensics to wildlife crime investigation routinely involves genetic species identification based on DNA sequence similarity. This work can be hindered by a lack of authenticated reference DNA sequence data resulting in weak matches between evidence and reference samples. The introduction of DNA barcoding has highlighted the expanding use of the mtDNA gene, cytochrome c oxidase I (COI), as a genetic marker for species identification. Here, we assess the COI gene for use in forensic analysis following published human validation guidelines. Validation experiments investigated reproducibility, heteroplasmy, mixed DNA, DNA template concentration, chemical treatments, substrate variation, environmental conditions and thermocycling parameters. Sequence similarity searches using both GenBank BLASTn and BOLD search engines indicated that the COI gene consistently identifies species where authenticated reference sequence data exists. Where misidentification occurred the cause was attributable to either erroneous reference sequences from published data, or lack of primer specificity. Although amplification failure was observed under certain sample treatments, there was no evidence of environmentally induced sequence mutation in those sequences that were generated. A simulated case study compared the performance of COI and cytochrome b mtDNA genes. Findings are discussed in relation to the utility of the COI gene in forensic species identification.     

Testing the reliability of frontal sinuses in positive identification

The use of frontal sinus radiographs in positive identification has become an increasingly applied and accepted technique among forensic anthropologists, radiologists, and pathologists. From an evidentiary standpoint, however, it is important to know whether frontal sinus radiographs are a reliable method for confirming or rejecting an identification, and standardized methods should be applied when making comparisons. The purpose of the following study is to develop an objective, standardized comparison method, and investigate the reliability of that method. Elliptic Fourier analysis (EFA) was used to assess the variation in 808 outlines of frontal sinuses by calculating likelihood ratios and posterior probabilities from EFA coefficients. Results show that using EFA coefficient comparison to estimate the probability of a correct identification is a reliable technique, and EFA comparison of frontal sinus outlines is recommended when it may be necessary to provide quantitative substantiation for a forensic identification based on these structures.     

SNP genotyping by multiplex amplification and microarrays assay for forensic application

OBJECTIVE: Research on the application feasibility of SNP genotyping for forensic identification by microarrays. METHODS: Oligonucleotide microarrays which could detect 34 different SNPs were used. After hybridization and washing, the arrays were scanned and fluorescence intensities analyzed using Microarray software. Population studies on 34 SNP loci were carried out in a sample of 109 unrelated Chinese Han individuals using oligonucleotide microarrays for genotype detection. The method was also applied to cases. RESULTS: According to the results of population studies, no deviations from Hardy-Weinberg equilibrium could be found. Among the 34 loci, 3 SNPs were low informative, 4 were medium informative and 27 were high informative. The combination discrimination power (CDP) of the 31 optimal polymorphic SNPs was 0.9999999999979. The matching probability was 2.13 x 10(-12). The average exclusion probability in paternity testing for duos was 0.9609. The average exclusion probability in paternity testing for trios was 0.9970. CONCLUSION: The data and case application demonstrated that SNP typing by oligonucleotide probe microarrays was a useful technique for paternity testing and individual identification. Combined with the 28 SNPs loci distributed on HLA-DRB1 and ABO genes, the combination discrimination power (CDP) was 0.9999999999999910. The matching probability was 9.02 x 10(-15). The average exclusion probabilities in duos and in trios were 0.9894 and 0.9992, respectively. It may be concluded that the 59 SNPs loci yield the same power in forensic identification as CODIS STRs currently used.     

Distribution of HLA DQA1, LDLR,GYPA, HBGG,D7S8, and GC locus alleles in the population of Russia

The distribution of chromosome locus alleles HLA DQA1, LDLR, GYPA, HBGG, D7S8, and GC of PolyMarker molecular genetic individualizing system was studied for the first time in a representative "mean statistical" sampling of Russian population. Typing of these locuses was carried out in 391 donors (no relatives) from 63 regions of the Russian Federation. The incidence of genotypes of all 6 locuses corresponded to the expected values, estimated on the basis of Hardy-Weinberg equilibrium hypothesis. This allows us to use the frequency characteristics of HLA DQA1 locus and the PolyMarker locuses determined in our study as the reference parameters for standard probability estimations in DNA identification. The frequencies of PolyMarker locuses alleles in the Russian sampling (in comparison with other ethnic groups) coincided best of all for allele frequencies in Europeoids living in the USA. For expert evaluation of the efficiency of using these locuses as molecular genetic markers with identification purposes, the discrimination potential was estimated separately for each locus and combinations thereof. HLA DQA1 locus was the most informative of the studied 6 locuses. The main population characteristics of this locus (probability of accidental coincidence, potential of discrimination--PD, polymorphism coefficient--PIC, exclusion potential--Pe, and mean value of parentage index--PI) were estimated for the population of Russia. The frequency distribution of alleles of the studied panel of locuses in the mean statistical Russian population obtained in our study can be used in molecular genetic personality identification and in anthropological studies.     

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.     

The database search problem: A question of rational decision making

This paper applies probability and decision theory in the graphical interface of an influence diagram to study the formal requirements of rationality which justify the individualization of a person found through a database search. The decision-theoretic part of the analysis studies the parameters that a rational decision maker would use to individualize the selected person. The modeling part (in the form of an influence diagram) clarifies the relationships between this decision and the ingredients that make up the database search problem, i.e., the results of the database search and the different pairs of propositions describing whether an individual is at the source of the crime stain. These analyses evaluate the desirability associated with the decision of 'individualizing' (and 'not individualizing'). They point out that this decision is a function of (i) the probability that the individual in question is, in fact, at the source of the crime stain (i.e., the state of nature), and (ii) the decision maker's preferences among the possible consequences of the decision (i.e., the decision maker's loss function). We discuss the relevance and argumentative implications of these insights with respect to recent comments in specialized literature, which suggest points of view that are opposed to the results of our study.     

miniSTR荧光检测体系的建立及法医学应用

目的 建立检测片段均小于150bp的miniSTR荧光检测体系,提高对微量降解检材DNA的检测效能. 方法 应用Primer Premier 5软件设计、FastPCR 6.0筛选引物,组合成用四色荧光标记引物的miniSTR复合扩增体系.优化PCR检测条件和引物浓度,在3100-Avant仪上用POP4胶进行电泳检测.分型结果用DNA标准品9947A和007进行验证,并通过检测新鲜血样、疑难微量检材评估该体系的法医学应用效能.结果 建立的miniSTR荧光检测体系（D12A TA 63、D2S1776、D1GA TA 113、D4S2408、D17S974、D20S482、D3S3053、Ame logenin、D6S474、D9S1122）中各基因座的检测片段均小于150bp,各等位基因扩增均衡性良好,无非特异性扩增产物,等位基因频率分布符合Hardy-Weinberg平衡,累积个体识别率为0.999999983,三联体累积非父排除率为0.996 8.能成功检测腐败肌肉组织、低拷贝数DNA检材以及在40％甲醛溶液中固定12d的人体组织. 结论 miniSTR荧光检测体系可独立应用于降解DNA样本的个体识别鉴定或补充应用于亲权鉴定,提高对微量、降解检材DNA的检测能力.     

31个SNP位点多重PCR扩增和芯片分型技术的建立及其法医学应用

目的对SNP基因分型芯片在个体识别中的应用价值进行研究。方法根据SNP不同等位基因的序列设计探针,制成分型芯片。采用4个复合PCR体系,用末端标记了Cy5的引物进行复合PCR扩增,产物与寡核苷酸探针进行杂交,根据杂交产生的荧光信号值确定样品在各SNP位点的基因型。将这一方法应用于109份样本的分型,根据基因型分布统计分析31个SNP位点的法医学应用价值。同时,进行家系调查和方法灵敏度分析。结果方法的灵敏度为1ng;所检测的31个SNP位点的累积个体识别率为0.9999999999979(偶合率为2.13×10-12),二联体亲子鉴定中累积非父排除率为0.9609,三联体亲子鉴定中累积非父排除率为0.9970。家系调查的结果表明,这些位点等位基因由亲代向子代的传递符合孟德尔遗传定律。结论上述31个SNP位点为中高信息量位点,适用于法医学个体识别,可作为当前STR系统的补充。     

毛细柱气相色谱保留指数法鉴定常见毒物的研究

本文描述了鉴定常见毒物的 Kovǎts 保留指数系统。研究了各种因素(测量时间、柱操作温度,柱前压等)对保留指数值测定的影响,并在三根不同极性柱上,以不同温度,测定了四十种药物的保留指数;提出用 C—R3A 计算保留指数的 BASIC 程序。     

Age Adjustment and Recall Bias in the Analysis of Domestic Violence Data: Methodological Improvements Through the Application of Survival Analysis Methods

This methodological paper presents the utility of survival analysis methods to provide age adjustment in the analysis of domestic violence data. These methods improve the estimation of lifetime probability of domestic violence, improve identification of patterns of first victimization over the lifespan, and provide methods of testing risk factors for first victimization while adjusting for the respondents' age. Most importantly, these methods allow a new investigation of recall bias. Results suggest that lifetime probability of abuse may have been substantially underestimated in previous studies because of problems in recall/disclosure encountered by middle-aged women.