Forensic Research & Technology

GSR particles from the surroundings of bullet hole have been characterized as a function of primer type and particle distribution. SEM images were used to verify size and shape of the GSR particles and EDS to verify the elemental composition in a single particle. Th e same specimens are further subjected to Time of Flight Secondary Ion Mass Spectrometry (ToF SIMS) and X-ray Photon Spectroscopy (XPS) analysis with a view to identify the respective surface chemistry, molecular nature and molecular mass of the GSR particles. Both inorganic and organic components of GSR in the elemental and combined form can be identifi ed using SIMS. Th e study was helpful in distinguishing between real GSR particle derived from a particular fi rearm and those derived from environmental contamination for forensic investigations. Shooting distance, type of fi rearm and nature of the incidents have been studied from the from characterization results.