Survival of forensic trace evidence on improvised explosive devices: perspectives on individualisation

Improvised Explosive Devices (IEDs) are weapons of modern times, used by terrorist groups and thereby causing substantial damage to communities. There is a widespread misconception that destructive conditions like heat, water or pressure destroy all forensic evidence. Moreover, the plausibility to detect identifiable fingermarks and DNA on components of IEDs is insufficiently known. Therefore, this study investigated the effects of neutralisation and explosion on latent fingerprints and touch DNA. In a majority of the cases, comparative fingermark- and DNA testing resulted in individualisation. In some cases, despite extremely low amounts of contact DNA detected after deployment of render-safe tools or detonation, full STR profiles could be constituted, even after applying fingerprint development techniques. This research shows that latent fingerprints and touch DNA on improvised explosives can be successfully detected after destructive conditions and possibly be linked to the perpetrators of such crimes. This individualising power offers perspectives to enhance forensic investigations of terrorism-related crimes.