An Introduction to GSR Analysis with AZtecGSR

Gunshot Residue (GSR) is a key piece of forensic evidence which can associate a suspect with some of the most serious crimes. GSR particles are formed from the condensed remnants of the bullet’s combusted primer and can have sizes in the range of 100s of nm to microns. These particles consist of the elements used in the primer – which traditionally were Pb, Ba and Sb, but now, with the advent of Pb-free ammunitions can contain other, more exotic elements. This means that the particles are both distinctive and small and therefore finding, measuring and positively identifying them as GSR is both a challenging and critical task – especially given that evidence of their presence is frequently used in court cases.

In this tutorial, we discuss AZtecGSR – a scanning electron microscope (SEM) based product for the detection and analysis of GSR that utilises the power and speed of Oxford Instruments’ Ultim Max or Xplore Energy Dispersive X-ray Spectroscopy (EDS) detectors. We discuss how, by taking advantage of the latest generation of EDS detectors and smart functionalities and algorithms in the AZtec NanoAnalysis suite, AZtecGSR can offer consistently high-quality results that give the confidence that is needed in this critical application at very high throughput levels and in an easy-to-use workflow.

You will learn how:

• The latest version of AZtecGSR reaches new levels of combined throughput and accuracy
• Both the current and historic versions of ASTM E1588 are implemented in the workflow and classification schemes
• The latest generation of Ultim Max and Xplore EDS detectors are the perfect tools for GSR analysis