Comparison of gunshot injuries caused from Tokarev, Makarov and Glock 19 pistols at different firing distances

Abstract

Töö eesmärgiks oli kuuli sisenemisavade võrdlemisel välja selgitada riide- ja nahavigastuste/sadestuste suhe laskekaugusega ning näidata, et relvaraua õõne ehitus mõjutab tahmasadestuse mustrit.

Eksperimentaallasud sooritati püstolitest Tokarev, Makarov ja Glock 19 standardse laskemoonaga 1 cm kuni 100 cm kauguselt. Võrreldi puuvillasele ja polüesterriidele ning nahale (lahangumaterjal) tekitatud vigastusi/sadestusi.

Järeldused: 1. Tulemused riietel ja nahal olid sarnased. 2. Erinevused leius olid tingitud laskekaugusest ja relvast. 3. Statistiliselt oluline seos oli laskekauguse ja riietel oleva tahmasadestuse läbimõõdu vahel, samuti laskekauguse ja püssirohuosakeste arvu vahel. Negatiivses seoses oli püssirohuosakeste arv ja nende paiknemiskoha kaugus riidedefekti keskkohast. Uurides laskekauguse ja püssirohu nahakihtides leidumise vahelist seost, ilmnes et püssirohuosakesed võivad tungida epidermisesse ja dermasse või jätta ainult pindmisi sissetungimisi/sadestusi. 4. Võrdluslaskude seeriate uurimine, kui lasud on tehtud väiksema vahemiku järel ja samalt kauguselt on teostatud suurem arv laske, annab paremad andmed statistiliseks uuringuks (tunnuste normaaljaotuse), mis võimaldab täpsemini lähilaske omavahel eristada ja laskekaugust kindlaks teha. 5. Püssirohu põlemisjääkide leid märklaudadele ja nende nahka tungimissügavus ei sõltu ainult laskekaugusest, vaid ka uuritavate osakeste paiknemiskohast materjalidefekti keskkoha suhtes. Sisenemisava keskkohast kaugenedes vähenes sadestuste tihedus märklaudadel ja vähenes püssirohu nahka tungimise sügavus. 6. Glock 19-st tulistamisel saadud uus leid tahmasadestuse mustris: tahmasadestuses oli näha heksagonaalse, polügonaalse või lilleõit meenutava kujuga alad. Heksagonaalse kujuga relvaraua õõs põhjustab erineva tahmasadestuse mustri võrreldes vintraua tavalise ehituse (Tokarevi ja Makarovi relvaraud) korral tekkiva tahmasadestusega.

The aim of the study was to identify the relationship between the firing distance and the degree of appearance of injuries/deposits on the cloths and skin, and to show the influence that the rifling of barrel has on the gunshot residue pattern comparing the bullet entrance injuries.

Test shots from the Tokarev and Makarov and Glock 19 pistols using the common ammunition at the distances of 1 cm to 100 cm were performed. There were compared the injuries/deposits produced to the cotton and polyester cloths and to the skin (autopsy material).

Conclusions: 1. The results on the cloths and on the skin were similar. 2. The differences in the findings were related to the firing distance and weapon. 3. A statistically significant correlation was found between the groups of the firing distance and the diameter of soot deposit, also between the firing distance and the number of the gunpowder particles on the cloths. The correlation was negative between the number of the gunpowder particles and their distance of the location from the centre of the cloth defect. Examining the correlation between the firing distance and penetration of the gunpowder into the skin layers, it became evident that the powder may penetrate into the epidermis and dermis or leave only superficial interspersions/deposits. 4. An examination of series of comparison shots fired from lesser intervals between firing distances and a greater number of shots fired at the same distance give better data for statistical analysis (normal distribution of variables) which enables more exact differentiation of close-range shots and determination of firing distance. 5. Besides the firing distance, detection of gunpowder residues on targets and their depth of penetration into targets are related to the distance of the location measured from the centre of the material defect. Increasing the distance from the centre of material defect to the periphery, the density of the deposits on the targets and the depth of the penetration of the gunpowder into the skin decreases. 6. In shots from the Glock 19 new finding was obtained concerning the soot pattern: hexagonal or polygonal or petal-like areas were visible in the soot deposits. The hexagonal boring causes a different soot pattern compared to the pattern produced in case of the traditional rifling (used in the Tokarev and Makarov).