Boiagina O. Forensic identification of blood stains age according to the chlorides content

The improvement of forensic expertise accuracy when estimating blood stains age has been grounded in the thesis using the methods of evidence-based medicine. Quantitative and qualitative indicators of accumulated maximum of blood chlorides distancing are used taking into account storage conditions and type of evidence. The scope of chloride method usage for paper and textile subjects-carriers is defined and it has also been proved that the use of chloride method is the most informative for material evidence of newsprint paper and silk. It has been proved that the rate of distancing and the distance between the blood stain and the edge are interrelated with the blood stains age. At the general ten-dency of increasing in course of time, the distance between the blood stain and the edge increased distinctly and clearly on the 7th day and the 14th day (р<0,05). The rate of blood chlorides distancing on the surface of textile subjects-carriers, in particular silk, depends on the age of their origin; the width of the chlorides edging increases on the 21st, 84th , 112th day (р<0,05). The sequence of forensic medical examination of material evidence for blood stains age estimation on the basis of chlorides contents has been determined. It includes: identification of the subject carrier type, considering probable terms of blood stain ori-gin, determination of storage conditions, measuring the width of chlorides edging. Fol-lowing this sequence can highly improve reliability of the expert's conclusions.