Interpol review of fire debris analysis and fire investigation 2019–2022

Cross-Contamination of Ignitable Liquid Residues on Wildfire Debris—Effects of Packaging and Storage on Detection and Characterization

“…Limited research exists on the effect of storage temperature on packaging materials and their sealing ability. Instead, storage temperature comparisons concentrate purely on the charcoal strip and often involve re-extraction of the same sample [11][12][13].…”

“…While existing literature does evaluate the suitability of packaging materials for ILR analysis, these evaluations are usually undertaken by GC-MS analysis without a back-ground matrix present [2,4,6,7,9]. Although real-world fire debris samples involve complex matrix effects [13][14][15][16], cross-contamination studies are conducted on non-competing materials, e.g., wipes or cloth [8,11], or pure materials of interest without other interferants present [10]. Several of these studies use thermal desorption for the investigation [6,7], which circumvents the potential for ILR profile distortion caused by extraction saturation and subsequent displacement from adsorbate-adsorbate interactions [2,17] encountered in passive headspace extraction with activated charcoal.…”

“…In wildfire debris analysis, the complexity of the matrix and the presence of combustion and pyrolysis compounds frequently lead to co-elutions with target ILR compounds. Comprehensive multidimensional gas chromatography (GC×GC) allows better separation between ILR compounds and complex sample matrix due to its increased separation potential and has been applied successfully in ILR analysis [13,18], and specifically wildfire investigations [13,15,19]. Cross-contamination research also does not evaluate the ability to retain sample integrity with different packaging layers of potentially mixed materials under various storage temperatures, despite this being an employed practice in arson investigations.…”

“…Chemometric analysis has been applied to ILR research-most frequently regarding detection and classification [13,20]-but is not commonly utilized in the context of sample integrity. GC×GC coupled with chemometric analysis showed promise in the detection and characterization of cross-contamination under matrix interference [21], with evaluation of false positive and false negative errors, indicating the presence of cross-contamination with confidence.…”

Rapid Detection of Accelerants in Fire Debris Using a Field Portable Mid-Infrared Quantum Cascade Laser Based Analyzer

“…Fires are a major concern for both public safety and economic reasons. Arson, the deliberate setting of fires to destroy property, to take human life or to obscure a crime scene is of particular concern and continues to be a problem worldwide [1]. Arson scenes are complicated and highly challenging for an investigator as much of the evidence is damaged by the fire in addition to any subsequent extinguishing efforts.…”