Use of Post-Mortem Computed Tomography in Disaster Victim Identification. Updated Positional Statement of the Members of the Disaster Victim Identification Working Group of the International Society of Forensic Radiology and Imaging; July 2019

This case report focuses on the findings in what appeared to be a planned complex pistol head shot and train suicide. The post mortem computed tomography (PMCT) scan in this instance yielded two interesting skull fragments among the many fragments of a highly fragmented body and head. These two fragments, based on initial resolution, appeared to show findings consistent with a firearm shot to the head. Upon reconstruction of higher resolution data, the necessary discrimination of non-gunshot related semi-circular fragment rims and firearm-related beveling matched the macroscopic aspect of the skull fragments. As a first lesson to be learned, a thorough examination of PMCT data in relatively high degrees of fragmentation may have to inspect all bone edges also for relatively subtle changes, possibly indicative of sharp force trauma or gunshot trauma. To that end, individual bone fragments should be placed on the scanner table carefully and with proper spacing, to expose their edges. Only this allows to capture data that avoids edge overlaps or edge collisions and that allows for optimal checking of the edges of all bone fragments for possible semicircular defects in the PMCT data. A second technical lesson to be learned is that particularly in instances of high fragmentation of at least parts of a body, resolution may have to be at least as good as maximally achievable. To that end, availability of the raw data to reconstruct images with maximal image quality rather than using a trade-off between lesser cost and lesser yield may be a key issue. A third lesson to be learned is that findings in relatively highly fragmented bodies as consequence of an apparent form of injury - fire/thermal, fall from great height, collision with a train - for other forms of trauma - sharp force trauma, firearm injury - may have to interpreted with caution, particularly with regard to what can be ruled out.