Post-Blast Explosives Attribution

The purpose of this project is to develop forensic methods for attributing explosive residue extracted from post-blast debris to suspected manufacturing sources. “Currently direct links and associations thereof between explosive residues extracted from post-blast debris and a suspected source cannot be made.” (NIST Organization of Scientific Area Committees, 2018) If developed, this novel capability would enable an additional mechanism for providing critical investigative leads and evidence for criminal prosecution.

During this two year applied research project, we propose to develop methods for attributing explosive residue extracted from post-blast debris to suspected manufacturing sources and perform field sample collection experiments to assess the potential for use of this technique in investigations. We will execute this project by:

• Developing methods to measure signatures of pre-blast explosives that may be relevant to post-blast residues (10 months)
• Performing a field sample collection effort to detonate explosives (at least three replications per explosive type) in the vicinity of a witness plate and collecting explosive residue from the witness plate and surrounding area (1 month)
• Measuring attribution signatures of the extracted explosive residue (6 months)
• Statistically comparing post- and pre-blast signatures through a collaboration with Professor Christopher Saunders at South Dakota State University (4 months)
• Preparing a publication detailing the findings and providing recommendations to further implement this novel forensic examination (2 months)

The key challenges will be 1) the low concentration of explosive residue remaining after detonation and 2) the potential for signature change post-blast due to detonation and environmental factors. Addressing these challendges will require 1) the development of efficient and sensitive methods of extraction/analysis and 2) a holistic, multi-technique approach to assess the best signatures/methodologies and fusion of data to increase reliability. We will leverage community-accepted trace explosive analysis protocols and Lincoln expertise in pre-blast attribution of explosive precursors (e.g., homemade explosives (HME) sourcing), large-scale outdoor phenomenology campaigns, and trace detection/identification of post-blast explosive residues to successfully execute this project. The study will result in prototype analytical methods, forensic phenomenology data on attribution potential for post-blast explosives, recommendations for gap-filling technology development, and at least one peer-reviewed publication. All methods and raw data will be made available for other researchers.