The identification and individualization of biological evidences is crucial to actual criminal investigations. In spite of the differences at the national level, all the legal processes attribute particular importance to forensic DNA analysis. However, none of the qualified results from any professional laboratory can produce substantive, valuable evidence with insufficient quality of samples and/or problems with provision of a pristine and controlled environment. The methodology and efficiency of sampling are distinct in case of living persons and in medico-legal autopsy and crime scenes. This chapter is a short overview from the basic introductory information up to ongoing research, and in accordance with constraints on the chapter size, it briefly discusses the important topics of sample collection at medico-legal autopsy for DNA analysis. The content sorts the major types of samples, reviews the common methods of sampling and the potential risk of poor sampling or contamination transfer. The corpses can be more or less degraded, which in special cases (e.g., paraffin embedded tissues, drowned, burning and/or buried cadaver) allow only for analysis of highly degraded samples. The samples can be associated with tissues of a corpse (e.g., blood, soft tissues, bone, tooth, hair) and/or additional extraneous tissues and remains, which are often mixed (e.g., blood, saliva, semen, vaginal fluid, debris of fingernails) on the corpse.
Part of the book: Post Mortem Examination and Autopsy
The importance of biological traces and evidences related to a criminal matter has been recognized for a long time. The examination of the expression of genetic polymorphism has been an integral part of the multidisciplinary field of medico-legal autopsy for over a century. Since the initial application of blood group antigens for personalization of a putative perpetrator in a murder case, the discipline of forensic genetics has evolved as a standard of forensic sciences. The real breakthrough, the application of molecular tools and processes for the in-vitro replication of genetic substances, has increasingly allowed the exploitation of advances of molecular genetics for both forensic and criminal investigations. Although there are certainly many more applications and scientific fields in the medico-legal arena, the relatively fast progress of genetics, which has accelerated recently with state-of-art technologies, can provide ever more relevant information in relation to a corpse or the cause and manner that resulted in the corpse for autopsy. This topic concerns the currently accepted forensic DNA technology, and the last section reviews commonly used markers for nuclear and mitochondrial DNA analysis as well as ongoing research. This review also focuses on the increasingly important non-human sources of DNA, and shortly covers the main aspects of animal forensic DNA examination.
Part of the book: Post Mortem Examination and Autopsy