Find a SECReT supervisor
Information for overseas students
View SECReT animation
Download SECReT brochure

The spatial distribution of post-blast RDX residue: Forensic implications

22 February 2012

Nadia Abdul-Karim

Published literature relating to forensic practices at bomb-scenes discusses methodologies for the collection and analysis of explosive related artefacts in detail. However, locating exactly where trace explosive residue samples should be sought during sample collection is not specified in these texts or guidelines; in this area it is generally acknowledged that forensic practices are based on tradition rather than evidence.

This study evaluates the current gap in published literature by assessing the spatial distribution of post-explosion RDX residue from a series of unconfined detonations, over a range of sampling sites at different detonation heights. Samples were collected from the central point of detonation and radiating sample sites. The results showed higher concentrations of residue to be found in the central region of the detonation, with decreases in residue recovery as the distance from the centre increased. This finding provides experimental evidence which corroborates previous residue distribution theories, whilst countering others. Interestingly, as the height at which the detonations occurred increased, the percentage recovery of residue was higher from all sampling sites. 

The findings of this study have a number of important practical implications for future forensic collection procedures, including determining where residue samples are best sought at crime scenes, and thus beneficial cost and time implications. During this project I was helped by the Metropolitan Police Counter Terrorism Unit. I conducted my experiments on the Explosives Range at Cranfield University's Shrivenham Campus and also carried out my analysis in their explosives laboratory.