Summary content. The dissertation presents theoretical generalization of the solution of an actual scientific task in forensic medicine that consists in justification of forensic medical diagnostic criteria of human body injuries and of clothing fabric damages caused at shots with the elastic bullets of "Teren-12P" cartridges from the 12th caliber smooth-bore guns, in particular of "Fort-500" model row. It is proven that the "Teren-12P" cartridge bullet is made of plasticized polyvinyl chloride that consists mainly of calcium (about 90 %) and of chlorine, strontium, lead, with the admixture of aluminum powder (of about 4-6 %). The bullet detected as radiopaque shadow of uneven moderate intensity under standard shooting conditions. This, in comparing to metal bullets with intense homogeneous shadow, can be considered as one of the diagnostic signs of this bullet. In the cases of penetrating wounds of body by an elastic bullet the most informing diagnostic method of research is a computer tomography. It is found that the difference in the barrel length of guns of "Fort-500" model row slightly affects the initial velocity of the bullets. At a shot distance of 3.5 m, the speed of the bullets may significantly exceed the speed range stated by the ammunition manufacturer (120-160 m/s). It is also set that at a shot distance of 3,5 m the bullets of "Teren-12P" cartridges have a considerable stopping action. At a shot in a chest and stomach with the minimum distance allowed by the ammunition manufacturer (20 m), the probability of death even at maximum values of the bullet speed does not exceed 0.05-0.07. Fire damages of clothing fabric at shots with the bullets of "Teren-12P" cartridges are polymorphic enough and depend on their physical, mechanical and trail-perceiving properties. At a hit at right angles bullets form on clothing fabric the characteristic round imprints-stamps with compressed and saucer-like deformation in facial layer of fabric, that represent the form of front cut of main part of bullet. The signs of thermal action at a shot with the "Teren-12P" cartridge bullet mainly appeared in the area of damages on clothing fabric at the distances range of "close up" -:- 5 cm. The soot layers in the areas of damages on clothing fabric at shots with the "Teren-12P" cartridges bullets are variable enough and depend not only on the shot distance but also on the structure of fabric surface, its abrasive trail-perceiving properties and on the character of fabric basis (lining). At shots with the "Teren-12P" cartridges bullets at distances range of "close up" -:- 10 cm the gunpowder grains are appear in a radius of 1-4 cm from the center of clothing fabric damage. It is found out that the main criteria of clothing fabric damages diagnostics with the "Teren-12P" cartridges bullets by means of x-ray fluorescent spectral analysis (XRF) are decrease in the intensity of lines of elements being in a control (before the shot) test, these are calcium, titan, chlorine and iron (the last two elements can be absent in a control test) and appearance of elements being absent in a control test - mainly these are iron, chlorine, zinc, arsenic, furnace, lead, copper. At shots with the "Teren-12P" cartridges bullets in biological human skin imitator - pig's skin from distances of 0-15 m damages appeared as deep abrasions and wounds of different form like bruises, in most cases, bullets were clearly visible in their gaps. Abrasions had the characteristic appearance of a round imprint-stamp with the formation of a skin compression area with a diameter of 1.8 cm, which displayed the shape of the front section of the main part of the bullet and was located in the center of the saucer-like skin impaction. It is proven that end-to-end damage to the skin and the adjacent layer of adipose tissue occurs in cases when the bullet velocity of the "Teren-12P" cartridge at the moment of collision exceeds 175 m/s, while the total length of the wound channel is within 5 cm, exceeding which guarantees the penetrating injuries with damage to vital organs. When conducting cross-correlation-regressive analysis of the data obtained during an experimental study for two types of human soft biological tissues imitators, paired and multiple regression models were obtained that provide an acceptable degree of error for calculating the dependencies of the residual cavity (dent) volume and its depth (length of the wound channel) from the shot distance and the bullet speed. Regressive models can be used in forensic medical examinations for determination of shot parameters based on depth and volume of the bodily harm caused by the "Teren-12P" cartridges bullets. According to the results of computer simulation, a number of tasks on the interaction of a bullet with an obstacle at different speeds was solved and a database on damage to human muscle tissue in the speed range of bullet use from 50 to 180 m/s was obtained. It is established the limit value of bullet speed for human muscle tissue (120 m/s), providing the formation of penetrating wounds of the body. Digital modeling also made it possible to determine ballistic effects that are not available for research in a full-scale experiment. The scope and sequence of forensic diagnostics of the human body injuries and of clothing damage caused by the "Teren-12P" cartridges bullets includes: determining the morphology of clothing damage and of the body soft tissues injuring, substantiating their gunshot nature, determining the depth and extent of damage, determining the presence and the nature of the close shot products, conducting the XRF areas of clothing fabric damage with the subsequent data processing obtained by the method of main components.
