Determination of the Perpetrator-Victim Position in a Case of Severe Traumatic Brain Injury due to a Less-Lethal Weapon Projectile, Based on Brain Injuries

Less-lethal (or non-lethal) weapons cause lethal and non-lethal injuries; this depends on many factors, including the shot distance and the modifications made to the operation of the weapon and the projectiles. This type of weapon has a similar shape to a firearm, shares the same physical and chemical operating principle and uses the combustion of a chemical substance to eject the projectile. In technical terms, the only difference is the projectile. Currently with the changes in weapons and projectiles, it is difficult to make a correlation. Just like lethal firearm projectiles and due to their operation, they leave macroscopic gunshot residues such as powder tattooing or soot deposition, only occasionally a contusion ring. In addition, there is a variety in the appearance of the entrance wounds. Therefore, it is very important to process the scene and carefully dissect the external wound and the surrounding area and, if possible, the recovery of the projectile. We present a case where a non-penetrating superficial injury to the skull produced trauma consistent with a coup contrecoup brain injury, which allows us to identify the perpetrator-victim position.