Application of soil in forensic science: residual odor and HRD dogs.
Decomposing human remains alter the environment through deposition of various compounds comprised of a variety of chemical constituents. Human remains detection (HRD) dogs are trained to indicate the odor of human remains. Residual odor from previously decomposing human remains may remain in the soil and on surfaces long after the remains are gone. This study examined the ability of eight nationally certified HRD dogs (four dual purpose and four single purpose) to detect human remains odor in soil from under decomposing human remains as well as soils which no longer contained human remains, soils which had been cold water extracted and even the extraction fluid itself. The HRD dogs were able to detect the odor of human remains successfully above the level of chance for each soil ranging between 75% and 100% accurate up to 667 days post body removal from soil surface. No significant performance accuracy was found between the dual and single purpose dogs. This finding indicates that even though there may not be anything visually observable to the human eye, residual odor of human remains in soil can be very recalcitrant and therefore detectible by properly trained and credentialed HRD dogs. Further research is warranted to determine the parameters of the HRD dogs capabilities and in determining exactly what they are smelling.
Department of Soil and Crop Sciences, Texas A&M University, College Station, TX, USA. Electronic address: michael-b-alexander@tamu.edu.
Michael B
MB
Alexander
Department of Entomology, Texas A&M University, College Station, TX, USA.
Theresa K
TK
Hodges
Department of Anthropology, Southeast Texas Applied Forensic Science Facility Sam Houston State University, Huntsville, TX, USA.
Joan
J
Bytheway
Department of Soil and Crop Sciences, Texas A&M University, College Station, TX, USA.
Jacqueline A
JA
Aitkenhead-Peterson
D000818:Animals; D004285:Dogs; D005188:False Negative Reactions; D005189:False Positive Reactions; D044707:Forensic Sciences; D006801:Humans; D009812:Odorants; D011180:Postmortem Changes; D012903:Smell; D012987:Soil / Q000737:chemistry*; D055549:Volatile Organic Compounds
D012987:Soil; D055549:Volatile Organic Compounds
Forensic science; Human remains; Human remains detection dogs; Post mortem interval (PMI); Residual cadaver decomposition island (RCDI); Volatile organic compounds (VOC's)