Chemistry Research and Practice

Effect of Incomplete Crime Scene Recovery on Forensic Attribution in Electrically Initiated IED Investigations: A Case-Based Analysis

Abstract

D Kumar, Tilak Raj

Improvised explosive devices (IEDs) are frequently employed in targeted attacks due to their adaptability and the accessibility of explosive precursors. Post-blast forensic investigation plays a vital role in reconstructing the incidents, identifying explosive materials, and supporting investigative acknowledgement. However, the reliability of forensic interpretation depends largely on the completeness and integrity of evidences identified and collected from the crime scenes. This work presents a forensic examination of an electrically initiated improvised explosive device (IED) incident in which only limited physical evidence was available/recovered for laboratory analysis. Two exhibits were received for examination: (i) a questioned electrical wire recovered from the crime scene and (ii) a control electrical wire submitted for comparative analysis. Chemical and instrumental examinations were conducted to detect inorganic explosive ions and organic explosive compounds, including nitrate, ammonium, sodium, potassium, TNT, RDX, PETN, and HMX. Additionally, comparative physical examinations of the wires were performed to evaluate structural characteristics such as copper strand configuration and electrical resistance. Analytical results revealed that there is no detectable explosive residues available on the questioned wire. Additionally, comparative examination demonstrated clear differences in copper strand count and electrical resistance between the questioned and control wires, indicating that the two exhibits were not identical. The absence of additional critical components, such as detonators, explosive residues, or container fragments, considerably restricted the scope of forensic reconstruction of the crime scene. These findings highlight the critical importance of comprehensive crime scene evidence recovery in post-blast investigations, as incomplete evidence collection can substantially limit forensic interpretation, attribution, and the overall evidentiary value of laboratory examinations.

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