Decompositional odor analysis database

This study, conducted at the University of Tennessee's Anthropological Research Facility (ARF), describes the establishment of the Decompositional Odor Analysis (DOA) Database for the purpose of developing a man-portable, chemical sensor capable of detecting clandestine burial sites of human remains, thereby mimicking canine olfaction. This "living" database currently spans the first year and a half of burial, providing identification, chemical trends and semi-quantitation of chemicals liberated below, above and at the surface of graves 1.5 to 3.5 ft deep (0.45 to 1.0 m) for four individuals. Triple sorbent traps (TSTs) were used to collect air samples in the field and revealed eight major classes of chemicals containing 424 specific volatile compounds associated with burial decomposition. This research is the first step toward identification of an "odor signature" unique to human decomposition with projected ramifications on cadaver dog training procedures and in the development of field portable analytical instruments which can be used to locate human remains buried in shallow graves.     

Stable-isotope fingerprints of biological agents as forensic tools

Naturally occurring stable isotopes of light elements in chemical and biological agents may possess unique "stable-isotope fingerprints" depending on their sources and manufacturing processes. To test this hypothesis, two strains of bacteria (Bacillus globigii and Erwinia agglomerans) were grown under controlled laboratory conditions. We observed that cultured bacteria cells faithfully inherited the isotopic composition (hydrogen, carbon, and nitrogen) of media waters and substrates in predictable manners in terms of bacterial metabolism and that even bacterial cells of the same strain, which grew in media water and substrates of different isotopic compositions, have readily distinguishable isotopic signatures. These "stable-isotopic fingerprints" of chemical and biological agents can be used as forensic tools in the event of biochemical terrorist attacks.     

Identification of a disinterred grave by molecular and stable isotope analysis

Confirmation of a potential disinterred grave was sought by GC and GC/MS analyses of lipid extracts of whole soils and white particulate matter. Fatty acid profiles and concentrations determined for three of the soils correlated with the deposition of a large amount of exogenous organic matter, most likely adipocere and/or decomposed body fat. Determination of C_16:0 and C_18:0 fatty acid δ¹³C values by GC/C/IRMS revealed the input to be isotopically distinct from common British domesticated animals, plotting closely to values determined for adipose fat obtained from of a murder victim. By considering the difference between δ¹³C values (Δ¹³C_18:0–16:0) a potential isotopic proxy for identifying the source of adipocere (human) and adipose tissue was proposed.     

Decomposition chemistry of human remains: a new methodology for determining the postmortem interval

This study was conducted to characterize the chemistry associated with the decomposition of human remains with the objective of identifying time-dependent biomarkers of decomposition. The purpose of this work was to develop an accurate and precise method for measuring the postmortem interval (PMI) of human remains. Eighteen subjects were placed within a decay research facility throughout a four-year time period and allowed to decompose naturally. Field autopsies were performed and tissue samples were regularly collected until the tissues decomposed to the point where they were no longer recognizable (encompassing a cumulative degree hour (CDH) range of approximately 1000 (approximately 3 weeks)). Analysis of the biomarkers (amino acids, neurotransmitters, and decompositional by-products) in various organs (liver, kidney, heart, brain, muscle) revealed distinct patterns useful for determining the PMI when based on CDHs. Proper use of the methods described herein allow for PMIs so accurate that the estimate is limited by the ability to obtain correct temperature data at a crime scene rather than sample variability.     

Problem solving and youth violence: an evaluation of the Boston Gun Project

The Boston Gun Project is a problem-solving policing initiativeaimed at reducing homicide victimization among young peoplein the city of Boston. It represented an innovative partnershipbetween researchers and practitioners to assess the city's youthhomicide problem and implement an intervention intended to havepowerful impacts in the near term. In early 1996, a workinggroup representing a variety of law enforcement and social serviceagencies implemented an intervention that strategically respondedto gang violence, focused enforcement efforts on gun trafficking,and emphasized communication of the strategy to generate deterrence.The intervention is associated with a 60% decline in youth homicidevictimization (i.e., two fewer victims per month). There aresmaller declines in other measures of violence. The declinein youth homicide is sharp and occurs coincident with the introductionof the intervention. Competing hypotheses appear unable to accountfor the decline.     

Time since death determinations of human cadavers using soil solution.

This study was conducted to collect data on specific volatile fatty acids (produced from soft tissue decomposition) and various anions and cations (liberated from soft tissue and bone), deposited in soil solution underneath decomposing human cadavers as an aid in determining the "time since death." Seven nude subjects (two black males, a white female and four white males) were placed within a decay research facility at various times of the year and allowed to decompose naturally. Data were amassed every three days in the spring and summer, and weekly in the fall and winter. Analyses of the data reveal distinct patterns in the soil solution for volatile fatty acids during soft tissue decomposition and for specific anions and cations once skeletonized, when based on accumulated degree days. Decompositional rates were also obtained, providing valuable information for estimating the "maximum time since death." Melanin concentrations observed in soil solution during this study also yields information directed at discerning racial affinities. Application of these data can significantly enhance "time since death" determinations currently in use.     

Odor analysis of decomposing buried human remains

This study, conducted at the University of Tennessee's Anthropological Research Facility (ARF), lists and ranks the primary chemical constituents which define the odor of decomposition of human remains as detected at the soil surface of shallow burial sites. Triple sorbent traps were used to collect air samples in the field and revealed eight major classes of chemicals which now contain 478 specific volatile compounds associated with burial decomposition. Samples were analyzed using gas chromatography-mass spectrometry (GC-MS) and were collected below and above the body, and at the soil surface of 1.5-3.5 ft. (0.46-1.07 m) deep burial sites of four individuals over a 4-year time span. New data were incorporated into the previously established Decompositional Odor Analysis (DOA) Database providing identification, chemical trends, and semi-quantitation of chemicals for evaluation. This research identifies the "odor signatures" unique to the decomposition of buried human remains with projected ramifications on human remains detection canine training procedures and in the development of field portable analytical instruments which can be used to locate human remains in shallow burial sites.