The effect of type of firearm and shooting distance on pattern distribution, particle dispersion and amount of gunshot residue

Abstract Background Evidence can be defined as the object’s availability and/or information that indicates whether a belief or proposition is true valid. Gunshot residue (GSR) an important evidence serve many roles in ballistic investigation such shooting distance, type of firearm and ammunition used related to GSR. However, due minimal amount GSR found crime scene, suitable methods technique are required order obtain from evidence. This action also known recovery. When fired, soot particles discharged any opening deposited at vicinity point shooting. Results study emphasized on examination soot/particles produced pattern distribution white cotton cloth target varying distances (from 3 50 cm) using video spectral comparator. Pattern particle density main factors determining clothing. Principle component analysis (PCA) hierarchical clustering (HCA) were classify firearms; differences highly recognizable. showed relationship between dispersion distance was proportionally linear. The results obtained test diameter residues being shots fired decreased greater than 21 cm. Conclusion will help investigators evaluating firearms used. There promising method for material which firing estimation.