Modelling Cranial Gunshot Wounds and Backspatter

Abstract

Bloodspatter from gunshot wounds may be divided into two categories; forward spatter and backspatter. Forward spatter is ejected from the exit wound and travels in the same direction as the bullet. Backspatter on the other hand is ejected from the entrance wound and travels against the line of fire, back towards the shooter. This means it is commonly deposited on the hand of the shooter or the firearm, making it a critical piece of evidence when determining the manner of death. Despite this fact, research in this area is limited and no realistic synthetic model for studying backspatter has been documented in the literature. This project was initiated in response to this, in an attempt to create a realistic cranial model that could produce backspatter from a gunshot wound.

A pig head model was developed, as it could be validated unlike a human model. This model consisted of synthetic skin, soft tissue and bone layers which completely enclosed a volume of gelatine to represent the brain. The model was tested at a firing range, along with butchered pig heads and live pigs and the results were compared. A high-speed camera was used to film each shot, in order to record key events in slow motion. The resultant wounds, the high-speed videos, and the backspatter produced were analysed and compared.

The model was comparable with pigs in relation to the backspatter produced and there were also similarities between the resultant wounds. The development of this pig model has therefore laid the foundations for creating a realistic human head backspatter model in the future. It was concluded that, with further development and testing, the model could potentially be a useful tool for forensic scientists, particularly in aiding their understanding and interpretation of backspatter from gunshot fatalities.