[Morphologic and morphometric aspects of contusion ring ("abrasion seam") of gunshot wounds].

Abstract

Test shots (cartridges .22 lr and 9 mm Parabellum) were fired on skin preparations taken from the lumbar region. As anticipated, with caliber .22 the outer diameter and the area of the abrasion ring were smaller than with the 9 mm caliber. This was true of both orthograde and inclined angle shots. In the case of vertical projectile impact, the outer diameter of the epidermis-free area was either smaller or only slightly larger than the cross-section of the projectile. The area of the abrasion ring exceeded the area of the entrance hole in the proportion of 3:1 (.22 lr) and 2.45:1 (9 mm Para), respectively. The epidermis bordering immediately on the abrasion ring was lifted off, with irregular and torn-in edges. Progressive drying up of this border zone simulated a time-dependent increase of the abrasion ring. If the bullet penetrated at an oblique angle, the eccentrically enlarged drying-up collar (on the side from which the bullet came) showed a tongue-shaped area of unaffected epidermis with an intact stratum corneum. This phenomenon can be explained by the wound-ballistic behaviour of the skin in inclined angle shots. Skin covered with a layer of water showed no abrasion collar around the entrance hole.