A Comprehensive Method for Forensic Soil Evidence Collection and Analysis in Post-Blast Investigations

Forensic soil evidence plays a crucial role in post-blast investigations, offering valuable insights into event reconstruction and establishing connections between individuals, locations, explosives, and devices. This study presents a comprehensive method for forensic soil evidence collection and analysis, focusing on the identification of nitrate ions in inorganic explosives. The methodology involves a systematic survey of the blast scene, sample collection from various locations, and proper documentation to maintain the chain of custody. Visual examination, physical and chemical analyses, and statistical validation were performed to characterize the soil composition and identify traces of explosive materials. Fourier Transform Infrared Spectroscopy (FTIR) and Ion Chromatography (IC) were employed to differentiate soil samples and provide insights into their matrix effect for qualitative and quantitative analysis of trace explosive elements. The study demonstrates the effectiveness of the proposed method across three scenarios: the effect of soil matrix on nitrate recovery, post-blast soil analysis from pyrotechnic debris, and field simulation under adverse environmental conditions. The results highlight the importance of optimizing soil sample mass, timely collection, and a multi-modal analytical approach combining chemical spot tests, FTIR confirmation, and IC quantification. The findings underscore the challenges posed by environmental factors and emphasize the need for standardized protocols and capacity building in regional forensic laboratories. This research provides actionable insights to enhance forensic outcomes in criminal and anti-terror investigations, contributing to the advancement of forensic soil analysis in post-blast scenarios.