A case study comparing the detection ability of cadaver detection dogs and electronic nose technology to a clandestine grave.

Cadaver detection dogs (CDDs) are one of the best tools to locate clandestinely buried human remains. However, large data gaps exist in what VOC classes and concentrations are targeted by CDDs for detection. This study compared the alert responses produced by CDDs used by the New South Wales Police Force to responses generated by an electronic nose (named the NOS.E) with metal oxide sensors to a clandestine burial. For confirmatory analysis, VOC samples of the clandestine burial were taken, and compounds were identified using GC × GC-TOFMS. While statistical work was limited due to sample sizes, inferences were made about VOC presence and concentration to NOS.E and detection dog ability. Both CDDs and NOS.E were able to detect targeted chemical classes (sulfur and nitrogen containing compounds, alcohols, alkanes and aldehydes) which was supported by GC × GC-TOFMS. Correlation analyses demonstrated non-significant, but observational patterns that CDDs true positive alerts were associated with higher NOS.E responses to sulfur and nitrogen containing compounds, alcohols and alkanes. Additionally, a "no alert" or "False Positive" alert was associated with lower NOS.E responses. This work supports that it is both the presence and abundance of VOC chemical classes that influence true positive alerts from CDDs to buried human remains.