UCL Centre for the Forensic Sciences


Explosives and gunshot residue (GSR)

Our research into Gunshot Residue (GSR) seeks to gain a much greater understanding of how this trace evidence behaves. It’s now possible to identify and collect very small traces of GSR from physical surfaces and people. But what does it mean when we find it? If we found GSR on your hand, does that mean you fired a gun? Or could it have transferred to your hand when you grabbed a handle on the bus or when you turned a door handle? Understanding how this evidence behaves is vital so we can provide robust forensic interpretations for the justice system. 

We also have a major focus on explosives, given that they’re one of the main tools of modern day terrorism. Our research covers the analysis and interpretation of explosive residue after an explosive event and the detection of precursors in advance of an explosion taking place. This research has considerable application to gathering intelligence before a crime has taken place (for example, identifying the location of a homemade bomb factory) as well as in forensic reconstruction after an explosion.

Current research

  • Experimental studies and the simulation of shooting incidents, with a focus on improving understanding of the behaviour and dynamics of GSR.
  • Investigating the transfer, secondary transfer, persistence and distribution of GSR following a firearm discharge, and providing empirical data that can be used to underpin the interpretation of this form of trace evidence in casework. 
  • Informing investigative procedures and protocols, with a view to maximising the value of GSR evidence to an investigation and minimising the potential for contamination. 
  • Primarily exploring the use of (automated) SEM-EDX for GSR analysis, but also applying complementary analysis techniques including X-ray fluorescence. 
  • Exploring the application of Bayesian Networks (BNs) to the interpretation of forensic evidence in legal contexts.
  • Post-blast scene examination of explosive residues.
  • Pre-emptive detection of hidden or discarded trace explosive material.
  • Developing highly selective and sensitive chemical sensors (electrochemical and fluorimetric), as well as powerful analytical techniques such as UHPLC-MS and electron microscopy. 
  • Assessing passive environmental monitoring techniques for sample collection in the field.

Research projects

  • Establishing empirical evidence bases for multiple transfers of GSR; the implications for interpretation.
  • The application of GSR recognition tools for forensic analysis of other forms of trace evidence.
  • Developing approaches for the visualisation of GSR.
  • Establishing detection methods for precursor chemicals in the wastewater system.
  • The application of nanomaterials in molecular recognition and chemical sensing devices.
  • Detection of vapour phase precursors relevant to IEDs using carbon-based nanomaterials as gas sensors for explosive precursor detection.
  • The use of synthesised metal-organic frameworks for the establishment of a sensory array for a portable explosive detection platform.