Forensic reconstruction of two military combat related shooting incidents using an anatomically correct synthetic skull with a surrogate skin/soft tissue layer

Abstract

Six synthetic head models wearing ballistic protective helmets were used to recreate two military combat-related shooting incidents (three per incident, designated 'Incident 1' and 'Incident 2'). Data on the events including engagement distances, weapon and ammunition types was collated by the Defence Science and Technology Laboratory. The models were shot with 7.62 × 39 mm ammunition downloaded to mean impact velocities of 581 m/s (SD 3.5 m/s) and 418 m/s (SD 8 m/s), respectively, to simulate the engagement distances. The damage to the models was assessed using CT imaging and dissection by a forensic pathologist experienced in reviewing military gunshot wounds. The helmets were examined by an MoD engineer experienced in ballistic incident analysis. Damage to the helmets was consistent with that seen in real incidents. Fracture patterns and CT imaging on two of the models for Incident 1 (a frontal impact) were congruent with the actual incident being modelled. The results for Incident 2 (a temporoparietal impact) produced realistic simulations of tangential gunshot injury but were less representative of the scenario being modelled. Other aspects of the wounds produced also exhibited differences. Further work is ongoing to develop the models for greater ballistic injury fidelity.

Ballistic trauma caused by military rifles: experimental study based on synthetic skull proxies

“…They do not come though without limitations. Whilst studies have shown that Synbone® exhibits a satisfactory reaction to impact as a cranial proxy [ 10 – 12 ] and can exhibit realistic reaction to ballistic injuries as demonstrated in the current study (e.g., hydraulic burst, Krönlein shot) there are still questions as to its suitability as a proxy for long bones [ 7 – 9 ]. Also, when ballistic testing on Synbone ® spheres used 7.62 × 39 mm ammunition at 50 m and 100 m the resulting injury patterns were considered to be “too comminuted and fragmented” when compared to contemporary military injuries encountered by participating physicians [ 12 ].…”

“…This study aimed to expand upon the work done by Taylor and Kranioti [ 13 ], Smith et al [ 6 ] Thali et al [ 10 , 11 ], and Mahoney et al [ 7 , 14 ] on testing whether Synbone® spheres are good proxies for human crania in ballistic studies and to record different injury patterns observed at different distances. It was found that the entry points of the ammunition into the spheres exhibit similar morphological patterns to real forensic cases when shot from a distance less than 35 m while exit wounds were larger than documented forensic cases.…”

“…Experimental ballistics and incident simulations have been broadly used as means to understand the effect of high energy impact on human proxies. Trauma simulations including ballistic testing have used both animal [ 2 , 3 ] and synthetic surrogates [ 4 ], spheres [ 5 , 6 ] and anatomically correct head proxies with variable results [ 7 ]. Whilst synthetic proxies for long bones appear problematic [ 4 , 8 , 9 ] it has been suggested that polyurethane spheres present efficient proxies for crania [ 6 ].…”

Defining Patterns and Behaviours of Forward Spatter Gunshot Misting

“…Secondly, the sponge is not contained in anything resembling human tissue; thus, different types of bloodstains can also be deposited on the paper, which can impact the bloodstain pattern size and shape. Mahoney et al [11] published a method that observed back spatter on a synthetic skull; this methodology used ballistic gel and a surrogate skin layer to yield similar results that would be found in real-life situations. This study was used as an aid to develop the methodology to observe forward spatter as it implied the importance of using ballistic gel as a substitute for human tissue.…”

Practical application of synthetic head models in real ballistic cases

“…Corpses or animals show several constraints, namely the ethical issue related to their use, the availability of specimens and the reproducibility of the results related to their heterogeneity [17,18]. Contrariwise, synthetic or non-humane biological materials showed a satisfactory to good level of reproducibility [5,18], in replacing human tissues like soft tissues (skin, muscle or brain tissue) or bones [1,14,[19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]. For ballistics tests, these synthetic or non-humane biological materials are usually used in a combined way by assembling them together in order to create a realistic wound model.…”