Establishment of the fact and features of the transfer by a firearm of a substance barrier made of multilayer and combined materials

Background. Currently, the issues of establishing the fact of a person being wounded by a firearm through a specific type of obstacle or due to a ricochet from it, as well as the identification of the material of the obstacle, have not been practically studied. Aims. Establishment of the fact and features of the transfer by a firearm of materials of multilayer and combined barriers (triplex, combined barrier made of keremogranite and foam concrete) when fired with 5.45x39 cartridges from a special shortened Kalashnikov assault rifle (AKSU). Material and methods. Shots were fired through various types of obstacles using a biological simulator of the human body from a distance of 5 meters. All experiments were recorded by means of high-speed video shooting using a Sony RX0 video camera with a frequency of 1000 frames per second. Bullets and their fragments extracted from the bullet trap or biological target tissues, after appropriate processing, were examined using a Leika M125 microscope, a Hitachi FlexSem1000 II scanning electron microscope and a Bruker Quantax 80 energy dispersive X-ray spectrometer. Results. Light microscopy of the firearms that overcame the obstacle revealed the presence of a characteristic deformation of the bullet when it breaks through each type of the studied obstacles. Scanning electron microscopy (SEM) and energy dispersion analysis (EDX) revealed in each case the presence of overlays of barrier particles on the entire surface of both deformed bullets and fragments of their shells and cores. Conclusion. The conducted experimental study proved that by means of SEM/EDX it is possible to reliably establish the fact of a gunshot wound of a person through a barrier of multilayer and combined materials.