The Capabilities of Olfactory Forensic Examination in the Investigation of Particularly Serious Crimes Against the Person of the Past Years

Research in recent years has significantly expanded the possibilities of examining human odour traces in the detection and investigation of particularly serious crimes against the person. The uniqueness of such studies lies in the use of specially trained dogs as an individual odour detector. The accuracy and reliability of such studies are not only comparable, but also exceed similar parameters of other types of modern instrumental biological research. The probability of error is one in a hundred million cases. The reliability of the results is determined by the research methodology, which includes a system of scientifically based and approved special tests and checks that are an integral part of the study. This allows evaluating each fact of the signal behavior of the animals used, recognising failures of their reflex and olfactory activity. The methodology of olfactory research of human odour traces is also used for scientific research in order to establish substances that determine the individual odour of a person. It has been found that these substances belong to polar lipids. From this, an innovative method of sample preparation was developed based on the isolation of individualising substances by chemical extraction. The method allows isolating these substances in the most purified form suitable for a further diagnostic analysis by instrumental thin-layer chromatography and for identification studies using the biosensor olfactory method. This significantly decreases the olfactory signal recognition threshold and allows extracting high-quality odour traces from the previously unsuitable materials and objects. This method allows examining highly contaminated objects that have undergone putrefactive changes, unsuitable for human identification by DNA analysis. The olfactory method has other advantages over DNA analysis. The examination of odour traces of a person allows establishing actual data about the event of a crime and its participants using objects of research stained with the victim's blood, even 35 or more years later. The olfactory method is the only biological method in forensic science that allows differentiating monozygotic twins. In addition, the odour traces that individualize the subject, obtained by chemical extraction, can be preserved in unfavorable conditions with a complete degradation and loss (for example, water washing) of cellular structures, which prevents the production of effective DNA analysis. Thus, modern olfactory expert research is an effective means of establishing the identity of a criminal, even in cases in which the use of other identification methods using human traces of biological origin is impossible.

Keywords

Authors

References