Profiling the decomposition odour at the grave surface before and after probing

Area of Science:

• Forensic Science
• Analytical Chemistry
• Environmental Science

Background:

• Human remains detection (HRD) dogs are vital for locating buried remains.
• Minimal odour at grave surfaces challenges canine detection.
• Soil probing is an invasive method to enhance odour availability.

Purpose of the Study:

• To investigate if soil probing increases volatile organic compounds (VOCs) at grave surfaces.
• To compare VOC abundance before and after probing using porcine remains.
• To analyze VOC profiles using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS).

Main Methods:

• Developed a proof-of-concept method for VOC collection without disturbing the burial.
• Collected VOCs from porcine remains in a controlled grave environment.
• Analyzed VOCs using GC×GC-TOFMS for sensitive decomposition odour profiling.

Main Results:

• VOC abundance was higher within the grave than at the surface, except when disturbed.
• Probing appeared to increase surface VOCs on some days, but trends were unclear.
• Prevalent grave VOCs were detected at the surface; trace VOCs varied over time.

Conclusions:

• Soil probing can release decomposition VOCs, but its effectiveness is influenced by environmental and burial variables.
• Further research is needed to understand these correlations.
• Probing should be considered secondary to non-invasive methods for HRD searches.