Cadaver Decomposition Research Articles

Lucilia eximia (Diptera: Calliphoridae) como indicador forense para el cálculo del intervalo post mortem en Costa Rica

Introducción: Lucilia eximia es una especie de amplia distribución geográfica en Costa Rica, cuyas poblaciones son estables durante todo el año. Las características biológicas de esta especie permiten concebirla como un potencial indicador forense para el cálculo del intervalo post mortem (IPM). El objetivo del estudio fue evaluar la aplicabilidad que podrían tener las características biológicas de poblaciones locales de L. eximia para calcular el IPM mínimo en Costa Rica mediante un modelo de acumulación de unidades térmica.Materiales y Métodos: Durante el experimento se sacrificaron mediante eutanasia dos cerdos domésticos (Sus scrofa) y se expusieron en un bosque premontano húmedo tropical. A partir de los mismos se recolectaron larvas de L. eximia a las 78, 144 y 192 horas posteriores al momento de muerte para continuar con su desarrollo en condiciones controladas. Con los datos generados se realizaron las retroproyecciones térmicas para efectuar el cálculo del IPM mínimo.Resultados: L. eximia requirió en total 7 236,50 horas grado acumulados (ADH) para culminar su ciclo vital. Los IPM mínimos calculados mediante el modelo de acumulación térmica para los tres momentos de colecta fueron 112,56; 153,60 y 104,64 horas. Únicamente el valor intermedio no presentó diferencias estadísticamente significativas con el tiempo conocido de muerte (p>0,05). Conclusiones: El modelo de acumulación térmica para el cálculo del IPM mínimo utilizando L. eximia como indicador forense brindó información precisa sobre el IPM mínimo sólo cuando se tomaron las muestras en el campo a las 144 horas, lo que perfila su utilidad para las primeras etapas de la descomposición cadavérica.

Comprehensive Approach for Monitoring Human Tissue Degradation

In recent years, comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC–TOFMS) has been reported as a suitable tool for the determination of volatile organic compounds (VOCs) emitted during the process of cadaveric decomposition. The main aim of the present study was to investigate temporal changes in VOC patterns during the decomposition process of various human tissues. The focus of previous research was mainly on the analysis of VOCs produced by whole cadavers. However, this study aimed to identify whether the VOCs produced during decomposition differ between specific organs, and further, to determine the extent of the variation between cadavers. The sampling process developed for this project allowed inter- and intra-cadaveric comparison. The headspace of heart, lung, liver, kidney and blood was monitored during the decomposition process. Tissue samples from five different cadavers were sampled regularly by dynamic pumping onto sorbent tubes that were further thermally desorbed onto a GC × GC–TOFMS system. A large amount of data (n = 774) was obtained, leading to challenges in the integration, interpretation and representation of the results. Eventually, multivariate statistical methods, such as principal components analysis (PCA) and hierarchical cluster analysis (HCA) were applied to the dataset to evaluate trends and differences in subgroups. It was demonstrated that there were subtle differences between the sets of compounds produced from each organ due to the different functions they carry out within the body. However, VOC profiles were more similar among organs from the same cadaver than when comparing samples from different cadavers. Various reasons may cause the differences between the analyzed cadavers, ranging from the individual diet and lifestyle to the time since death.

Environmental necrophagous fauna selection in a funerary hypogeal context: The putridarium of the Franciscan monastery of Azzio (northern Italy)

Insects play a fundamental role in the removal and recycling of the organic matter from human cadavers and animal carcasses. Several factors can affect both the cadaver decomposition and colonisation by insects and other animals. Accessibility to the body is one of these factors. The archaeological, anthropological and entomological investigations conducted inside the Crypt of the Franciscan Monastery in Azzio (Varese, northern Italy) allowed the reconstitution of the funerary practices used by a Franciscan community between the 17th and 18th centuries and provides a good example of necrophagous entomo-fauna selection. Human remains were found in the putridarium chamber, a semicircular room with sixteen narrow and semicircular niches, where bodies were located until the complete decomposition of the soft tissues. Numerous puparia were collected from the bones, the clothes and the niche walls. The majority belonged to Hydrotaea capensis (Diptera: Muscidae) and a few puparia of scuttle flies in the family Phoridae were detected among the studied material. Fragments of beetles in the families Staphylinidae and Cryptophagidae were also sampled. The entomological findings clearly support the hypothesis that the bodies were quickly transferred into the crypt after death and that the specific hypogeal (subterranean) environment selected the entomofauna community composition. The observations here reported with similar entomological findings cited in the literature support the hypothesis of a specific selectivity on insects' community by underground environments (e.g. graves, crypts). This conclusion can be applied to outline a common pattern in archaeological contexts and in indoor forensic cases.

Changes in soil nutrients (ammonia, phosphate and nitrate) associated with rat carcass decomposition under tropical climatic conditions

Changes in soil nutrients have been applied in legal investigations of the time of death or to locate a clandestine grave. However, research on forensic soil chemistry under the tropical climate conditions in Malaysia is at its infancy, with few data available for forensic investigations. This study aims to study changes of soil nutrients (i.e. ammonia, phosphate and nitrate) as well as soil pH and electrical conductivity (EC), and the associated stages of decomposition of rat carcasses (n = 3) under controlled tropical climate conditions. The results showed differences in soil pH between control and carcass soils. Soil EC and concentrations of ammonia and phosphate increased during early decomposition stages, and declined thereafter. Nitrate concentration increased at the later stage of decomposition. We also found that the top layer of soil (i.e. 5 cm from surface) rendered a significant pattern of soil nutrient dynamics compared with soil at 10 cm from the surface, possibly due to a slower rate of vertical transfer and the washing-off effect. We suggest that the soil EC value and changes of soil nutrients in the top 5 cm of the soil layer have potential in forensic investigation to determine the minimum post-mortem interval and serve as an indicator for hidden graves and cadaver decomposition islands.

Application of High-throughput Sequencing in Researches of Cadaveric Microorganisms and Postmortem Interval Estimation.

Necrobiome is the main factor causing the cadaver decomposition. Studying the microbial succession during decomposition is one of the main tasks of forensic microbiology. The interactive relationships among cadaver, environment and microorganisms are complicated. The microbial succession study relies on macroscopic monitoring of community composition and the diversity change in each decomposition stage. With the maturity and development of high-throughput sequencing （HTS）, the structure and diversity of microbial communities in different environments have been successively revealed. A new breakthrough to explore the cadaveric microorganisms has been opened as well. It has become the research hotspots in forensic microbiology to reveal the microbial succession in the process of cadaver decomposition and to interpret the essence of various decomposition phenomena by using HTS, which can provide a new reference for postmortem interval （PMI） estimation. The present paper reviews studies on PMI estimation by using cadaveric microorganism. Problems and application prospects of forensic microbiology studies are discussed on the basis of the current application of HTS technology in the exploration of microbial succession.

Massive colonization of human remains by the microscopic fungus Scopulariopsis brevicaulis Bainier

A filamentous microscopic fungus, Scopulariopsis brevicaulis Bainier, was found colonizing the surface of human remains discovered in particular environmental conditions. Different physiological tests were carried out in order to assess which of the environmental parameters promoted the proliferation of fungus on the corpse, as well as to understand the biological processes that occurred during the cadaver decomposition. The results showed that the fungal strain displayed a strong proteolytic activity, which helped the fungus to colonize the skin of the corpse, in accordance with the growing assays on chicken and pork skin, on which the fungus grows successfully and rapidly. The fungus also grew well in an atmosphere that was poor in O2 and rich in CO2, and in the presence of a high amount of NH4+ at alkaline pH, conditions that are commonly found during the putrefaction of remains. All these results, together with the low frequency of S. brevicaulis propagules in the air, allowed us to make another assumption: that the fungus S. brevicaulis was present in the surroundings of the individual before his death, which probably then infected the skin or other anatomical areas, and the effects of the death (the production of gases from gasoline combustion, the isolation of the remains, which reduces dramatically their exposure to environmental biotic and abiotic factors that could have led to faster deterioration) facilitated significantly the spread of the fungus over the surface of the individual.

Trimethylamine in postmortem tissues as a predictor of postmortem interval estimation using the GC method.

Trimethylamine (TMA), a simple amine in volatile compounds, indicating the spoilage degree of meat, related with the late postmortem interval (PMI) during the cadaver decomposition process. In this paper, a headspace gas chromatography (HS-GC) method has been successfully built to analyze the content of TMA in postmortem rat tissues (liver, myocardial and skeletal muscle tissues), which is used for PMI estimation with the wide range of PMI (0-720 h postmortem) at 16 °C ± 1 °C. Correspondingly, three equations about the relationship between the PMI and TMA content were established, in which they showed that the TMA content in all three tissues increased from the firstly detected time to 192 h and gradually decreased after 384 h. Furthermore, the TMA measurement in five human samples was carried out and the results (<35 h PMI) showed a good agreement about the change trend of TMA content between human and rat, which elucidated that this research might provide a new insight for the forensic scientist to band HS-GC technology together with TMA determination in the PMI estimation.

Steroid fingerprints: Efficient biomarkers of human decomposition fluids in soil

The decomposition of animal and human cadavers can lead to comprehensive chemical and biochemical changes in soil, which can provide helpful information for the analysis of archaeological and crime scenes. The current study focused specifically on the concentration and distribution patterns of steroids in soil with the aim of assessing their suitability for demonstrating the presence of human decomposition products. Soil samples were collected from a forensic site where a human corpse had been lying on the soil surface for 18 days. Total organic carbon (TOC) and steroid concentrations were analysed in soil samples taken from beneath the body at the time the corpse was removed and also one year later. High concentrations of TOC and steroids were detected close to the soil surface at the time the body was removed, and the concentration of cadaver-derived cholesterol was considerably higher than that of the plant-derived sitosterol. The soil beneath the cadaver contained higher concentrations of faeces-derived 5β-stanol coprostanol than the control soil. Different concentrations and distribution patterns of steroid compounds in the soil upon removal of the corpse and one year later indicate that significant transformation, degradation and translocation processes had taken place during this period of time. The depth distribution of steroids beneath a decomposing body along with changes in the human steroidal fingerprints in soil over time were found to provide information that could help resolve forensic and archaeological issues. The combined analysis of tissue steroids (cholesterol), the reduction product of cholesterol in soil (5α-cholestanol) as well as faecal steroids (coprostanol, 5β-stigmastanol and their conversion products epicoprostanol and epi-5β-stigmastanol) represent excellent additions to the forensic toolbox for determining whether a soil of interest has ever been affected by a human cadaver or not.

Special delivery: scavengers direct seed dispersal towards ungulate carcasses

Cadaver decomposition islands around animal carcasses can facilitate establishment of various plant life. Facultative scavengers have great potential for endozoochory, and often aggregate around carcasses. Hence, they may disperse plant seeds that they ingest across the landscape towards cadaver decomposition islands. Here, we demonstrate this novel mechanism along a gradient of wild tundra reindeer carcasses. First, we show that the spatial distribution of scavenger faeces (birds and foxes) was concentrated around carcasses. Second, faeces of the predominant scavengers (corvids) commonly contained viable seeds of crowberry, a keystone species of the alpine tundra with predominantly vegetative reproduction. We suggest that cadaver decomposition islands function as endpoints for directed endozoochory by scavengers. Such a mechanism could be especially beneficial for species that rely on small-scale disturbances in soil and vegetation, such as several Nordic berry-producing species with cryptic generative reproduction.

Reduced efficiency of tropical flies (Diptera) in the decomposition of snail cadavers following molluscicide poisoning

Decomposition is a key ecosystem service that reduces non-living organic matter, returning nutrients to the soil. In this study, we examine the responses by fly (Diptera) communities to molluscicide-poisoned apple snail (Pomacea canaliculata) cadavers in a tropical rice production landscape. Fewer molluscicide-poisoned cadavers were colonised by decomposer flies (niclosamide = 61% of cadavers with fly larvae; methaldehyde = 53%; Camellia sp. seed extract [saponin] = 50%) compared to control (freezer-killed) cadavers (81%). Metaldehyde, niclosamide and saponin reduced the abundance (average 51% reduction), biomass-density (average 63% reduction) and species richness (average 38% reduction) of flies emerging from the snail cadavers. The decay of control cadavers was generally faster (57% more tissue removed over 3 days) than molluscicide-treated cadavers. We suggest that poisoned carcasses potentially affect ecological communities across a range of trophic levels.

Insects of forensic importance associated to cadaveric decomposition in a rural area of the Andean Amazon, Caquetá, Colombia

ABSTRACT Forensic entomology is a frequently used tool to estimate the time interval between death and the discovery of the corpse. Succession of arthropods associated with cadaveric decomposition was monitored in a rural area of the Municipality of Florencia, Department of Caquetá, Colombia. Three pigs (Sus scrofa) were used as study models. Insect sampling, and monitoring of carcasses and environmental conditions were carried out every five hours. The total time from death to skeletonization was of 545 hours (22.7 days). A total of 30833 insect individuals were collected. Specimens were distributed in nine orders, 46 families, 95 genera and 106 species. Diptera was the most abundant, with 23215 individuals (75.3%), followed by Coleoptera, with 3711 individuals (12%), and Hymenoptera, with 3154 individuals (10.2%). Immature stages of Cochliomyia macellaria, Chrysomya albiceps, Hemilucilia semidiaphana and Ophyra aenescens were the main species involved in tissue consumption and acceleration of the decomposition process. Due to the presence of ants Cheliomyrmex sp., Camponotus sp. and Dinoponera sp., and coleopterans Hister sp., Acylophorus sp. and Philonthus spp., it was not possible to obtain sufficient Diptera egg masses for rearing the colonizing species. These results can be used as a standard to determine the postmortem interval in criminal investigations in the rural area of the Andean Amazon, Caquetá, Colombia.

Earthworm-induced shifts in microbial diversity in soils with rare versus established invasive earthworm populations.

European earthworms have colonised many parts of Australia, although their impact on soil microbial communities remains largely uncharacterised. An experiment was conducted to contrast the responses to Aporrectodea trapezoides introduction between soils from sites with established (Talmo, 64 A. trapezoides m-2) and rare (Glenrock, 0.6 A. trapezoides m-2) A. trapezoides populations. Our hypothesis was that earthworm introduction would lead to similar changes in bacterial communities in both soils. The effects of earthworm introduction (earthworm activity and cadaver decomposition) did not lead to a convergence of bacterial community composition between the two soils. However, in both soils, the Firmicutes decreased in abundance and a common set of bacteria responded positively to earthworms. The increase in the abundance of Flavobacterium, Chitinophagaceae, Rhodocyclaceae and Sphingobacteriales were consistent with previous studies. Evidence for possible soil resistance to earthworms was observed, with lower earthworm survival in Glenrock microcosms coinciding with A. trapezoides rarity in this site, lower soil organic matter and clay content and differences in the diversity and abundance of potential earthworm mutualist bacteria. These results suggest that while the impacts of earthworms vary between different soils, the consistent response of some bacteria may aid in predicting the impacts of earthworms on soil ecosystems.

Forensic Entomology:an overview

Insects are the most important, in terms of number and diversity, group of animals on the earth. Insects have colonized all the world’s environments and are associated with both human life and death. Although their economical and sanitary importance is well documented, in the past few years they have been used also in a forensic context. In forensic entomology, necrophagous insects have proved useful in; studying postmortem interval (PMI), postmortem transfer (the movement of a body from one location to another after death), presence of drugs or poisons, and in identifying the victim and/or the suspect. Many species can be used to estimate the minimum PMI (mPMI), according to the stage of cadaver decomposition, body exposure, geographical region, and season. The most important British flies of forensic interest are described.

Temporal and Spatial Impact of Human Cadaver Decomposition on Soil Bacterial and Arthropod Community Structure and Function.

As vertebrate carrion decomposes, there is a release of nutrient-rich fluids into the underlying soil, which can impact associated biological community structure and function. How these changes alter soil biogeochemical cycles is relatively unknown and may prove useful in the identification of carrion decomposition islands that have long lasting, focal ecological effects. This study investigated the spatial (0, 1, and 5 m) and temporal (3–732 days) dynamics of human cadaver decomposition on soil bacterial and arthropod community structure and microbial function. We observed strong evidence of a predictable response to cadaver decomposition that varies over space for soil bacterial and arthropod community structure, carbon (C) mineralization and microbial substrate utilization patterns. In the presence of a cadaver (i.e., 0 m samples), the relative abundance of Bacteroidetes and Firmicutes was greater, while the relative abundance of Acidobacteria, Chloroflexi, Gemmatimonadetes, and Verrucomicrobia was lower when compared to samples at 1 and 5 m. Micro-arthropods were more abundant (15 to 17-fold) in soils collected at 0 m compared to either 1 or 5 m, but overall, micro-arthropod community composition was unrelated to either bacterial community composition or function. Bacterial community structure and microbial function also exhibited temporal relationships, whereas arthropod community structure did not. Cumulative precipitation was more effective in predicting temporal variations in bacterial abundance and microbial activity than accumulated degree days. In the presence of the cadaver (i.e., 0 m samples), the relative abundance of Actinobacteria increased significantly with cumulative precipitation. Furthermore, soil bacterial communities and C mineralization were sensitive to the introduction of human cadavers as they diverged from baseline levels and did not recover completely in approximately 2 years. These data are valuable for understanding ecosystem function surrounding carrion decomposition islands and can be applicable to environmental bio-monitoring and forensic sciences.

Evaluation of Soil Chemical Properties During Cadaveric Decomposition and its Applications to Forensic Chemistry

A estimativa do intervalo pos-morte (IPM) e um parâmetro fundamental na investigacao de crimes contra a vida. Em locais de clima tropical, a decomposicao cadaverica ocorre de forma acelerada, impedindo a estimativa do IPM pelos metodos usuais. Entender como as diferentes circustâncias afetam a decomposicao cadaverica e crucial para o desenvolvimento de metodos que possam estimar o IPM em diversas condicoes climaticas. Uma das alternativas, porem pouquissimo explorada no Brasil, refere-se a utilizacao da quimica do solo na determinacao de IPM longos. Nesta pesquisa, as variacoes das caracteristicas quimicas do solo foram monitoradas durante a decomposicao cadaverica de carcacas suinas em area de mata tropical, a fim de reconhecer padroes e avaliar a aplicabilidade destes pela pericia criminal. Dentre as caracteristicas avaliadas estao os niveis de pH, nitrogenio inorgânico (amonia e nitrato), nitrogenio total, razao carbono nitrogenio (C:N), aluminio trocavel, fosforo disponivel e macro e micronutrientes. Os resultados apresentaram variacoes distintas de acordo com as fases de decomposicao observadas e tambem com a forma com que as carcacas foram depositadas no ambiente de estudo (acima ou abaixo do solo), evidenciando a possibilidade de se empregar estas variacoes no desenvolvimento de modelos para a previsao de intervalos pos-morte com duracao de ate 67 dias.

Artropodofauna cadavérica asociada a cerdo doméstico (Sus scrofa) en un ambiente ribereño en Chubut, Argentina

Este es el primer estudio de descomposición cadavérica realizado en un ambiente ribereño en la región NO de la provincia de Chubut Argentina, cuyo objetivo fue determinar la composición específica, la abundancia y la diversidad de la artropodofauna cadavérica asociada a un modelo experimental porcino. Se realizaron muestreos estacionales durante tres años consecutivos (2010 - 2012) utilizando en cada muestreo tres cerdos, colocados dentro de jaulas de madera cubiertas de alambre tejido. Diariamente se colectaron los insectos en el cuerpo, debajo y alrededor de este. Se identificaron y caracterizaron las cinco etapas del proceso de descomposición de los cadáveres de cerdo experimentales. Se recolectaron 6.325 individuos adultos e inmaduros pertenecientes a 63 especies de 18 familias distribuidas entre los órdenes Diptera, Coleoptera e Hymenoptera. Se determinó la estacionalidad de Compsomyiops fulvicrura (Diptera: Calliphoridae) durante la época cálida y la dominancia de Calliphora vicina (Diptera: Calliphoridae) en la época fría. Los resultados obtenidos aportan información relevante sobre la fauna de insectos saprófagos en el ambiente ribereño al río Chubut, que puede ser utilizada como herramienta en la estimación de la data de muerte en casos forenses humanos en la región estudiada.

Solenopsis saevissima (Smith) (Hymenoptera: Formicidae) Activity Delays Vertebrate Carcass Decomposition

Ants are among the insects involved in cadaveric decomposition processes, as they exhibit predatory and necrophagous behavior. Red ants exhibit an aggressive behavior, which impacts carcass colonization, accelerates or delays the decomposition rates and potentially confounds interpretation of the post-mortem interval. Here, we estimated the effects of Solenopsis saevissima (Smith) activity on the decomposition rate in domestic pig carcasses. We placed two pig carcasses close to S. saevissima nests, and two other pig carcasses (controls) in other locations 50 m away from the nest. Decomposition processes were delayed by at least three days for carcasses on the nest compared to those without direct exposure to ants. Our results showed that predatory activity of S. saevissima interfered with carcass colonization by scavenger insects, functioning as an ecological barrier to the establishment of immature Diptera. Such results highlight the importance of considering ecological processes that may interfere with mechanisms determining post-mortem intervals.

Diversity of the Formicidae (Hymenoptera) carrion communities in Lisbon (Portugal): preliminary approach as seasonal and geographic indicators

ABSTRACTThe value of the Formicidae (Insecta, Hymenoptera) community in forensic investigations is poorly studied in Portugal. In order to better understand the structure and dynamics of this group of insects in cadavers and their putative value in forensic investigations, studies were carried out in Lisbon area during one year. Piglet carcasses were used as a model of human decomposition. The entomofauna attracted to the carcasses was collected over a period of about 2 months in each season of the year. The collection of ants was performed at regular intervals, daily in the first 23 days and then with intervals of 2, 3 or 5 days until the end of the experiment. Five stages of cadaveric decomposition were recognized with the ants being present in all of them. Three hundred and nine specimens were captured: 7 in autumn, 6 in winter, 90 in spring and 206 in summer. These specimens belong to three subfamilies and seven different species. Four of them had never been mentioned before as being associated to cadavers in this geographical area. Spring and summer had the greater diversity of species and a larger number of individuals. Temnothorax luteus was the dominant species in spring and Tapinoma nigerrimum in summer. Corroborating the information of other similar studies carried out in the Iberian Peninsula, the sarcosaprophagous Formicidae community found in Lisbon is unique and different from other studied locations, which supports the need to perform regional studies. Our results shown that ants do not present a definite pattern of succession, but some species have the potential to be seasonal or geographic indicators.

The evolutionary logic of sepsis

The recently proposed Microbiome Mutiny Hypothesis posits that members of the human microbiome obtain information about the host individuals' health status and, when host survival is compromised, switch to an intensive exploitation strategy to maximize residual transmission. In animals and humans, sepsis is an acute systemic reaction to microbes invading the normally sterile body compartments. When induced by formerly mutualistic or neutral microbes, possibly in response to declining host health, sepsis appears to fit the ‘microbiome mutiny’ scenario except for its apparent failure to enhance transmission of the causative organisms.We propose that the ability of certain species of the microbiome to induce sepsis is not a fortuitous side effect of within-host replication, but rather it might, in some cases, be the result of their adaptive evolution. Whenever host health declines, inducing sepsis can be adaptive for those members of the healthy human microbiome that are capable of colonizing the future cadaver and spread by cadaver-borne transmission. We hypothesize that such microbes might exhibit switches along the ‘mutualist – lethal pathogen – decomposer – mutualist again’ scenario, implicating a previously unsuspected, surprising level of phenotypic plasticity.This hypothesis predicts that those species of the healthy microbiome that are recurring causative agents of sepsis can participate in the decomposition of cadavers, and can be transmitted as soil-borne or water-borne infections. Furthermore, in individual sepsis cases, the same microbial clones that dominate the systemic infection that precipitates sepsis, should also be present in high concentration during decomposition following death: this prediction is testable by molecular fingerprinting in experimentally induced animal models.Sepsis is a leading cause of human death worldwide. If further research confirms that some cases of sepsis indeed involve the ‘mutiny’ (facultative phenotypic switching) of normal members of the microbiome, then new strategies could be devised to prevent or treat sepsis by interfering with this process.

An evaluation of soil chemistry in human cadaver decomposition islands: Potential for estimating postmortem interval (PMI)

Soil samples from the Forensic Anthropology Research Facility (FARF) at Texas State University, San Marcos, TX, were analyzed for multiple soil characteristics from cadaver decomposition islands to a depth of 5centimeters (cm) from 63 human decomposition sites, as well as depths up to 15cm in a subset of 11 of the cadaver decomposition islands plus control soils. Postmortem interval (PMI) of the cadaver decomposition islands ranged from 6 to 1752 days. Some soil chemistry, including nitrate-N (NO3-N), ammonium-N (NH4-N), and dissolved inorganic carbon (DIC), peaked at early PMI values and their concentrations at 0–5cm returned to near control values over time likely due to translocation down the soil profile. Other soil chemistry, including dissolved organic carbon (DOC), dissolved organic nitrogen (DON), orthophosphate-P (PO4-P), sodium (Na+), and potassium (K+), remained higher than the control soil up to a PMI of 1752days postmortem. The body mass index (BMI) of the cadaver appeared to have some effect on the cadaver decomposition island chemistry. To estimate PMI using soil chemistry, backward, stepwise multiple regression analysis was used with PMI as the dependent variable and soil chemistry, body mass index (BMI) and physical soil characteristics such as saturated hydraulic conductivity as independent variables. Measures of soil parameters derived from predator and microbial mediated decomposition of human remains shows promise in estimating PMI to within 365days for a period up to nearly five years. This persistent change in soil chemistry extends the ability to estimate PMI beyond the traditionally utilized methods of entomology and taphonomy in support of medical-legal investigations, humanitarian recovery efforts, and criminal and civil cases.