A patterned abrasion caused by the impact of a cartridge case may simulate an atypical muzzle imprint mark

Reversed configuration of the muzzle imprint mark in a pistol contact entrance wound mimicking a non-suicidal act

The muzzle imprint mark characteristically associated with contact or near contact entrance gunshot wounds exemplifies one of the most informative external findings in forensic medical practice. The presence of the muzzle imprint mark on the body's surface proves ballistic trauma, point of entry, and range of fire. Moreover, its appearance and configuration may indicate the type of the involved weapon and the way the firearm had been positioned and held at the time of discharge. In this paper, we present the contact shot wound pattern of an 83-year-old man who committed suicide with a Frommer Stop 12 M autoloading pistol of caliber 7.65 mm Browning. Initially, the muzzle imprint mark configuration in relation to the entrance gunshot defect in the victim's right temple indicated an unusual application or orientation of the pistol's barrel during discharge, thus, strongly suggesting a non-suicidal act. However, a critical confrontation of postmortem findings along with the results of ballistic expertise provided a clear explanation, which comprised the remarkable construction and unique muzzle design of the used handgun.

Interpol review of forensic firearm examination 2016-2019

This review paper covers the relevant literature on forensic firearm examination from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.

Rearward movement of the slide in semi-automatic pistols: a factor potentially influencing the configuration of muzzle imprint marks in contact shots

A muzzle imprint mark is a highly diagnostic finding, which indicates a contact shot. In many cases, it also provides additional information on the type of the weapon used and on the way in which it was held at the time of firing. In semi-automatic pistols, some constructional elements constituting the muzzle plane move to the rear together with the slide, which may prevent them from causing a corresponding imprint close to the bullet entrance hole. The present study comprises 30 consecutive autopsy cases of fatal contact shots to the head inflicted with semi-automatic pistols. The imprint marks accompanying the entrance wounds were compared with the muzzle ends of the respective weapons both before and after retracting the slide. It turned out that in a considerable number of cases (3 out of 30), the retractable parts were not depicted or only to a minor degree as components of the imprint mark. In order to validate the presumed correlation, experimental shots were fired to composite models using pistols in which the movable and the stationary parts forming the muzzle plane were dyed with different paints. Thus, it could be demonstrated that the muzzle imprint preferentially mirrors the front sides of the stationary parts such as the barrel end, the recoil guide, and the gun housing. Immediately after discharge, the slide and the ballooning skin of the bullet entrance site move in the same direction. The stationary parts of the weapon block the expansion of the skin bulging towards the muzzle, so that the skin gets firmly pressed against them. The dynamic interaction between the gun and the entrance region resulting in a characteristic imprint mark could be visualized by the use of a high-speed motion camera recording test shots to different composite models.