Haploid vererbte Polymorphismen des Y-Chromosoms sind wichtige diagnostische Werkzeuge der forensischen Genetik und verwandter Disziplinen, insbesondere der Anthropologie. Geschlechtsspezifität und uniparentaler Erbgang der Merkmale ermöglichen eine Reihe von Untersuchungen, die mit autosomalen Markern erfolglos bleiben müssen. Kurze tandem-repetitive STR-Sequenzen, die polymorphen Marker der Wahl im forensischen Labor, sind auch auf dem Y-Chromosom nachzuweisen. Aufgrund der rekombinationsfreien, paternalen Vererbung des größten Teils des Y-Chromosoms werden locus-spezifische Allele hier en bloc, als hochinformativer Haplotyp, vererbt. Die forensische Untersuchung profitiert insbesondere auf dem Gebiet der Untersuchung biologischer Spuren von der Y-chromosomalen Diagnostik: vor allem in Vergewaltigungsfällen kann die männliche DNA-Fraktion der Abstrichpräparate unabhängig von der weiblichen des Opfers untersucht und individualisiert werden. Bei der Abstammungsuntersuchung wird in solchen Fällen die Y-chromosomale Analyse empfohlen, in denen der Vater (eines männlichen Kindes) nicht zur Verfügung steht und paternale Verwandte an seiner statt untersucht werden müssen. Von den 14 evaluierten Y-chromosomalen STR-Systemen sind 9 für die forensische Praxis ausgewählt und empfohlen worden. Sie bilden den sogenannten "minimal haplotype", der heute international für die o. g. Analysen verwendet und von der zuständigen Fachgesellschaft (International Society of Forensic Genetics) in ihren Richtlinien empfohlen wird. Wegen der immensen Haplotyp-Variabilität und des uniparentalen Erbgangs ist die Frequenzbestimmung, und damit die Entscheidungsfindung für rechtsmedizinische Gutachter, nur über den Zugang zu großen Datenbanken möglich. Zu diesem Zweck wurde an der Charité die "European Y-STR Haplotype Reference Database" eingerichtet, die Frequenzabfragen auf Grundlage des aktuellen Datenmaterials online ermöglicht (http://ystr.charite.de). Aufgrund des uniparentalen Erbmodus und der im Vergleich zu Autosomen verringerten effektiven Zahl von Y-Chromosomen in der Population muß mit einem meßbaren Einfluß genetischer Drift auf die Y-STR-Haplotyp-Verteilung in der Population gerechnet werden. Mit Hilfe der AMOVA (Analysis of Molecular Variance) - Methode konnten genetische Distanzen für eine repräsentative Auswahl von über 50 weltweit verteilter Populationen berechnet werden. Der AMOVA-Test ist unentbehrlich für die Überprüfung der Eignung von Referenzdatenbanken als Grundlage der Frequenzbestimmung von Y-STR-Haplotypen. / There are a number of merits that qualify the Y chromosome as a special forensic genetic tool: the male specificity for most of its length, the absence of recombination which provides unambiguous male lineage's and the small effective population size that tends to create population specific allele distributions of the Y chromosomes. Particularly in cases of rape and other sexual assault as well as in kinship testing, Y-STR haplotyping can help to close informativity gaps. Since the main goal of forensic genetics is individualization of persons or lineages of descent an analytical strategy for the male chromosome must enable the expert to differentiate between the majority of unrelated haplotypes. For this to achieve the choice of the sequence type and its variability (i.e. its mutation rate) as well as the number of individual sequences to be used for profiling is crucial. We have introduced a STR profile for the Y-chromosome consisting of 11 microsatellite sequences which is both informative for individualization purposes as well as for a genetic distance analysis of populations. The technical simplicity of the approach led to a rapid introduction of the technique in many of the forensic labs world-wide. Intense international collaboration facilitates the generation of large haplotype reference databases, most of them are online available and searchable (Europe: http://ystr.charite.de and USA: http://www.ystr.org/usa/). By use of haplotype specific parameters such as the molecular distance (which equals the minimum number of mutational steps separating two haplotypes) and the largest available haplotype databases a Bayesian approach to evaluate Y-STR haplotype matches has been proposed. Directly inspired by our work are the recommendations of the International Society of Forensic Genetics (ISFG). These guidelines state some basic principles on forensic analysis using Y-STR polymorphisms: the use of sequenced allelic ladders, the application of a repeat-based nomenclature and the use of suitable haplotype reference databases for statistical evaluation of matches. Still a matter of research , but of the utmost interest is the potential of the Y-chromosome analysis to unravel the ethnological background of a given male profile. A dual approach - that using Y-STRs as well as Y-SNPs - probably renders the maximum amount of information about the descent of a male lineage typed in a forensic specimen.

DNA is identified as a powerful tool in the solving of rape cases, but it is often destroyed either by members of the public or the police officials who attend to the scene. The aim of the study was to evaluate the management of DNA evidence in rape cases in the Bishop Lavis Policing Area. To address the research topic under investigation, research questions, a legal framework and policies were used. The outcome of the study indicated poor performance in securing the crime scene and ensuring that physical evidence is preserved and not tampered with. On this basis, it was recommended that developmental workshops and intensive training on the management of DNA evidence be conducted to all members of the South African Police Service attend to rape crime scenes. This should be done to equip them with knowledge and an understanding of the management of DNA evidence. / Police Practice / M. Tech. (Forensic Investigation)

The advances in molecular biology have increased the production of enormous amount of genetic information in a small period of time. This capacity of data production motivated the researchers to increase the rhythm of their researches. This necessity demands the use of efficient softwares in order to manage these data. Besides this, it also demands the development of good softwares in order to assist the researchers in the task of analyzing the data and giving them a biological meaning in a brief space of time. This work proposes a software model that will support the study of Forensic DNA, whose main repository is the autossomic DNA. This software intends to support the researchers in the identification of condemned persons or persons that are suspected of a crime. It also intends to assist the researchers in the study of paternity and the search for disappeared persons. The results of this work will be applied in the Forensic DNA Laboratory of UFAL. The software modeled here has four modules study of paternity , criminal , disappeared people and the bank of populational frequencies . The modules were modeled independently from each other, considering the specifications related to the analysis of genetic links. The software was developed using the JAVA programming language together with PostgreSQL database. Both are free software and have an excellent relationship between cost and benefit usage / Fundação de Amparo a Pesquisa do Estado de Alagoas / Os avanços da biologia molecular vêm favorecendo a geração de uma enorme quantidade de informações genéticas em um tempo cada vez menor. Essa capacidade de geração de dados permite que os pesquisadores acelerem o ritmo de suas pesquisas, exigindo a utilização de ferramentas eficientes para o gerenciamento desses dados. Outra necessidade está relacionada com o desenvolvimento de ferramentas computacionais com capacidade de auxiliar na tarefa de análisar e dar um significado biológico a estes dados em um breve espaço de tempo para os pesquisadores. Este trabalho propõe a modelagem de um ambiente de apoio à análise e ao estudo do DNA Forense, cujo principal repositório seja o DNA autossômico. Este ambiente visa dar suporte a identificação de pessoas condenadas ou suspeitas de ter realizado algum tipo de crime contra a sociedade, bem como auxiliar no estudo de paternidade e na busca de pessoas desaparecidas. Este ambiente irá atender ao Laboratório de DNA Forense, da UFAL, que vêm realizando estas atividades. O modelo do ambiente aqui proposto, possui quatro módulos, estudo de paternidade , criminal , desaparecido e o banco de freqüência das populações . Os módulos foram modelados de forma que funcionem independentemente, atendendo as especificações inerentes à análise sobre vínculo genético. O sistema foi desenvolvido na linguagem de programação JAVA com banco de dados PostgreSQL. Ambas as ferramentas possuem característica de software aberto e uma relação custo/benefício excelentes

Indiana University-Purdue University Indianapolis (IUPUI) / DNA phenotyping is a rapidly developing area of research in forensic biology. Externally visible characteristics (EVCs) can be determined based on genotype data, specifically from single nucleotide polymorphisms (SNPs). These SNPs are chosen based on their association with genes related to the phenotypic expression of interest, with known examples in eye, hair, and skin color traits. DNA phenotyping has forensic importance when unknown biological samples at a crime scene do not result in a criminal database hit; a phenotype profile of the sample can therefore be used to develop investigational leads. IrisPlex, an eye color prediction assay, has previously shown high prediction rates for blue and brown eye color in a European population. The objective of this work was to evaluate its utility in a North American population. We evaluated the six SNPs included in the IrisPlex assay in an admixed population sample collected from a U.S.A. college campus. We used a quantitative method of eye color classification based on (RGB) color components of digital photographs of the eye taken from each study volunteer and placed in one of three eye color categories: brown, intermediate, and blue. Objective color classification was shown to correlate with basic human visual determination making it a feasible option for use in future prediction assay development. In the original IrisPlex study with the Dutch samples, they correct prediction rates achieved were 91.6% for blue eye color and 87.5% for brown eye color. No intermediate eyes were tested. Using these samples and various models, the maximum prediction accuracies of the IrisPlex system achieved was 93% and 33% correct brown and blue eye color predictions, respectively, and 11% for intermediate eye colors. The differences in prediction accuracies is attributed to the genetic differences in allele frequencies within the sample populations tested. Future developments should include incorporation of additional informative SNPs, specifically related to the intermediate eye color, and we recommend the use of a Bayesian approach as a prediction model as likelihood ratios can be determined for reporting purposes.

Democratic and accountable policing is one of the hallmarks of democracy. In a healthy democracy, a police service exists to protect and support the rights of its community by successfully listening to those who are laying complaints and resolving to assist them by bringing the perpetrators to the grinding wheels of justice. Encouraging and ensuring that police officials utilise the most modern means of investigation such as the DNA technology, provides the necessary balance to the exercise of professional discretion and heightened conviction rate by the police officials. The utilisation of biological evidence in investigation of rape cases is such a modern intervention – a way of providing insulation against internal and external interference with the proper and successful investigation of rape cases. / Forensic Investigation / M. Tech. (Forensic Investigation)

Democratic and accountable policing is one of the hallmarks of democracy. In a healthy democracy, a police service exists to protect and support the rights of its community by successfully listening to those who are laying complaints and resolving to assist them by bringing the perpetrators to the grinding wheels of justice. Encouraging and ensuring that police officials utilise the most modern means of investigation such as the DNA technology, provides the necessary balance to the exercise of professional discretion and heightened conviction rate by the police officials. The utilisation of biological evidence in investigation of rape cases is such a modern intervention – a way of providing insulation against internal and external interference with the proper and successful investigation of rape cases. / Forensic Investigation / M. Tech. (Forensic Investigation)