A Longitudinal Study on Human Outdoor Decomposition in Central Texas

The development of a methodology that estimates the postmortem interval (PMI) from stages of decomposition is a goal for which forensic practitioners strive. A proposed equation (Megyesi et al. 2005) that utilizes total body score (TBS) and accumulated degree days (ADD) was tested using longitudinal data collected from human remains donated to the Forensic Anthropology Research Facility (FARF) at Texas State University‐San Marcos. Exact binomial tests examined the rate of the equation to successfully predict ADD. Statistically significant differences were found between ADD estimated by the equation and the observed value for decomposition stage. Differences remained significant after carnivore scavenged donations were removed from analysis. Low success rates for the equation to predict ADD from TBS and the wide standard errors demonstrate the need to re‐evaluate the use of this equation and methodology for PMI estimation in different environments; rather, multivariate methods and equations should be derived that are environmentally specific.     

An Aquatic Decomposition Scoring Method to Potentially Predict the Postmortem Submersion Interval of Bodies Recovered from the North Sea

This study aimed to develop an aquatic decomposition scoring (ADS) method and investigated the predictive value of this method in estimating the postmortem submersion interval (PMSI) of bodies recovered from the North Sea. This method, consisting of an ADS item list and a pictorial reference atlas, showed a high interobserver agreement (Krippendorff's alpha ≥ 0.93) and hence proved to be valid. This scoring method was applied to data, collected from closed cases—cases in which the postmortal submersion interval (PMSI) was known—concerning bodies recovered from the North Sea from 1990 to 2013. Thirty‐eight cases met the inclusion criteria and were scored by quantifying the observed total aquatic decomposition score (TADS). Statistical analysis demonstrated that TADS accurately predicts the PMSI (p < 0.001), confirming that the decomposition process in the North Sea is strongly correlated to time.     

The Effects of Sharp‐Force Thoracic Trauma on the Rate and Pattern of Decomposition

Given the multiple factors that may alter the rate of decomposition, one of the more difficult tasks that anthropologists and pathologists face is determining of the postmortem interval (PMI). While trauma has been widely accepted as being among those factors, recent published studies have contradicted this premise. However, major issues exist with these studies. Consequently, this study was designed to simulate a more realistic setting in an effort to settle this discrepancy in the literature. This study utilized eight porcine remains; three of which received incised wounds penetrating the thoracic cavity, three others received nonpenetrating wounds, and two were designated nontrauma controls. Measurements included evaluating the total body score (TBS) on temporal and accumulated degree days (ADD). Using a two‐way repeated measures ANOVA, the results of this study found that while trauma does have an influence in the pattern of decomposition, it does not influence the rate of decomposition.     

Differential decomposition patterns in charred versus un-charred remains

Although researchers have examined many aspects of fire modification, the rate and pattern of decomposition in charred remains have not been studied previously. This study utilized 48 domestic pigs, divided into 24 charred (head, neck, and limbs burned to Crow-Glassman level 1 and torso to level 2) and 24 un-charred pig carcasses. Decomposition of control carcasses was scored at 50 accumulated degree days (ADD) intervals, and charred carcasses were also observed and photographed at this time. A Charred Body Scale was subsequently created, and charred carcasses were scored retrospectively for the same ADD intervals. Analysis using a mixed-effect repeated measures model indicated that, while decomposition rate was not statistically different between the two groups (p = 0.2692), the charred remains initially displayed an ostensibly more advanced pattern. Body regions displaying significant charring decomposed at a faster rate (p < 0.001), while areas with very light levels of charring decomposed at a significantly slower rate (p < 0.001).     

The formation of early stage adipocere in submerged remains: a preliminary experimental study

In some circumstances, the presence of adipocere may retard decomposition and complicate postmortem interval estimation. This article explores the correlation between Accumulated Degree Days (ADD) and early stage formation of adipocere. Sixty wild rabbit (Oryctolagus cuniculus) carcasses were used in this experiment; a control group (N = 30) deposited directly on the ground surface and an experimental group (N = 30) completely submersed in water in individual buckets. Data (water and inner body temperature, pH, and total body score) were collected every 100 ADD. Results indicated that early stage adipocere is correlated to ADD and that its formation on submersed remains is more likely to occur after 630 ADD. Skin sloughing promoted the formation of adipocere. No adipocere was formed on any of the control group rabbits. This study also highlights the fact that multiple factors influence adipocere formation and it is suggested that further research needs to be conducted into this area.     

The Influence of Preburial Insect Access on the Decomposition Rate

Abstract: This study compared total body score (TBS) in buried remains (35 cm depth) with and without insect access prior to burial. Sixty rabbit carcasses were exhumed at 50 accumulated degree day (ADD) intervals. Weight loss, TBS, intra‐abdominal decomposition, carcass/soil interface temperature, and below‐carcass soil pH were recorded and analyzed. Results showed significant differences (p << 0.001) in decomposition rates between carcasses with and without insect access prior to burial. An approximately 30% enhanced decomposition rate with insects was observed. TBS was the most valid tool in postmortem interval (PMI) estimation. All other variables showed only weak relationships to decomposition stages, adding little value to PMI estimation. Although progress in estimating the PMI for surface remains has been made, no previous studies have accomplished this for buried remains. This study builds a framework to which further comparable studies can contribute, to produce predictive models for PMI estimation in buried human remains.     

Postmortem changes of human bodies on the bathyal sea floor--two cases of aircraft accidents above the open sea

Forensic taphonomy in the marine context recently received growing attention. However, only limited information is available about the fate of human bodies at greater sea depth. Following two fatal aircraft accidents (west of Namibia, south of Sicily) human remains were recovered from a depth of 540-580 m (both cases) after 3 months (Namibia)/34 days (Sicily). In the Namibia case fully skeletonized bones were lifted. In the Sicily case a complete, dressed body was found exhibiting a partially skeletonized skull, starting adipocere formation and pink teeth. The rate and mode of decomposition of human bodies in the deep sea varies considerably and is mainly influenced by the local faunal composition. Of special relevance for the understanding of both cases was the oceanographic observation that the highly efficient necrophageous lyssianassids are abundant off Namibia but are rare in the Mediterranean, emphasizing the importance of collaboration of forensic and marine scientists in such case work.     

Measuring Desiccation Using Qualitative Changes: A Step Toward Determining Regional Decomposition Sequences

The creation of a regional decomposition scoring system for western Colorado provides a model for the creation of regional systems. The development of a scoring system requires: (1) human remains, not proxies, (2) longitudinal observations, and (3) large sample size. First, an enhanced system (total body desiccation score; TBDS) was developed through observations of 40 human remains. This effort produced a categorical scoring model augmented by qualitative categories of gross tissue change. The new model was tested with retrospective photographic packets. A sample of eight donors with data collected over 3 years was selected. Monthly data points over a maximum of a 3‐year period yielded 112 data points. Correlations between TBDS and accumulated degree‐days (ADD), and total body score (TBS) and ADD were approximately equal for a TBS below ~20, but the TBDS correlated better with ADD at higher TBS scores >20. The TBDS may be used to refine postmortem interval (PMI) models in areas where remains desiccate.     

Putrefaction: An Additional Complicating Factor in the Assessment of Freshwater Drownings in Rivers

Background hypothesis: That bodies immersed in freshwater (rivers) may show greater changes of decomposition than bodies immersed in saltwater (sea). Fifty de‐identified river drownings and 50 sea drownings were randomly selected from autopsy files at Forensic Science SA, Adelaide, Australia and assessed for decomposition. Results: The river cases consisted of 43 males and seven females (M:F 6:1); age range of 2–92 years (mean 46.8 years); decomposition—16/50 (32%); postmortem interval 1–14 days, average 3.8. The sea cases consisted of 36 males and 14 females (M:F 2.6:1); age range of 9–81 years (mean 50.7 years); decomposition—2/50 (4%) (p < 0.001%); postmortem interval 1–6 days, average 2.8. As decomposition reduces information obtained at autopsy, postmortem examination of deaths in rivers may be less informative than deaths that have occurred in the sea. The reasons for less decomposition in the sea include cooler temperatures, exposure to salt and shorter postmortem intervals.     

Using accumulated degree-days to estimate the postmortem interval from decomposed human remains

Forensic anthropologists often rely on the state of decomposition to estimate the postmortem interval (PMI) in a human remains case. The state of decomposition can provide much information about the PMI, especially when decomposition is treated as a semi-continuous variable and used in conjunction with accumulated-degree-days (ADD). This preliminary study demonstrates a supplemental method of determining the PMI based on scoring decomposition using a point-based system and taking into account temperatures in which the remains were exposed. This project was designed to examine the ways that forensic anthropologists could improve their PMI estimates based on decomposition by using a more quantitative approach. A total of 68 human remains cases with a known date of death were scored for decomposition and a regression equation was calculated to predict ADD from decomposition score. ADD accounts for approximately 80% of the variation in decomposition. This study indicates that decomposition is best modeled as dependent on accumulated temperature, not just time.     

Detecting Submerged Bodies: Controlled Research Using Side‐Scan Sonar to Detect Submerged Proxy Cadavers

Forensic investigators routinely deploy side‐scan sonar for submerged body searches. This study adds to the limited body of literature by undertaking a controlled project to understand how variables affect detection of submerged bodies using side‐scan sonar. Research consisted of two phases using small and medium‐sized pig (Sus scrofa) carcasses as proxies for human bodies to investigate the effects of terrain, body size, frequency, swath width, and state of decomposition. Results demonstrated that a clear, flat, sandy pond floor terrain was optimal for detection of the target as irregular terrain and/or vegetation are major limitations that can obscure the target. A higher frequency towfish was preferred for small bodies, and a 20 m swath width allowed greater visibility and easier maneuverability of the boat in this environment. Also, the medium‐sized carcasses were discernable throughout the 81‐day study period, indicating that it is possible to detect bodies undergoing decomposition with side‐scan sonar.     

Percentage of body recovered and its effect on identification rates and cause and manner of death determination

Anthropologists frequently encounter cases in which only partial human remains are recovered. This study reports how the percentage of the body recovered affects identification (ID) rates and cause and manner of death determination. A total of 773 cases involving anthropology consults were drawn from the New Mexico medical examiner's office (1974-2006). Results indicate a significant correlation between body percent recovered and ID rates, which ranged from 89% for complete bodies to 56% when less than half the body was present. Similar patterns were evident in cause/manner determination, which were the highest (83% and 79%, respectively) in complete bodies but declined to 40% when less than half the body was found. The absence of a skull also negatively impacted ID and ruling rates. Findings are compared with general autopsy ID rates (94-96%) and cause/manner determination rates (96-99%) as well as prior published rates for individual casework and mass death events.     

Inter‐Rater Reliability of Total Body Score—A Scale for Quantification of Corpse Decomposition

The degree of body decomposition can be quantified using Total Body Score (TBS), a scale frequently used in taphonomic or entomological studies of decomposition. Here, the inter‐rater reliability of the scale is analyzed. The study was made on 120 laymen, which were trained in the use of the scale. Participants scored decomposition of pig carcasses from photographs. It was found that the scale, when used by different people, gives homogeneous results irrespective of the user qualifications (the Krippendorff's alfa for all participants was 0.818). The study also indicated that carcasses in advanced decomposition receive significantly less accurate scores. Moreover, it was found that scores for cadavers in mosaic decomposition (i.e., representing signs of at least two stages of decomposition) are less accurate. These results demonstrate that the scale may be regarded as inter‐rater reliable. Some propositions for refinement of the scale were also discussed.     

An Appraisal of Decomposition Cases Received at the Johannesburg Forensic Pathology Service Medico‐legal Mortuary During 2010–2011

Decomposed bodies pose many questions for researchers regarding environmental effects, cause of death, and patterns. This study aimed to observe the factors associated with decomposed bodies autopsied at the Johannesburg Forensic Pathology Service Medico‐legal Mortuary. A total of 4876 autopsies were conducted from 2010 to 2011, of which 109 were decomposed. Black individuals made up the largest proportion (67%) followed by White (26%). Males comprised 86.2%, while 12.8% were female. The mean age was 42.78 years. Most cases were in the early stages of decomposition (49.5%), with 32.1% bloated, 11.9% in active decay, 2.8% in advanced decay, and 3.7% were skeletal. Insect activity was identified in 25.7% of decomposition cases. Cause of death was determined in 48.6% of cases. Of all the cases, 64% were found indoors and 23% outdoors, while 23% had insufficient information regarding the location. Of considerable interest was the number of cases from hospitals and clinics.     

Preliminary Observations of Arthropods Associated with Buried Carrion on Oahu

Several studies in Hawaii have focused on arthropod succession and decomposition patterns of surface remains, but the current research presents the first study to focus on shallow burials in this context. Three domestic pig carcasses (Sus scrofa L.) were buried at the depths of 20–40 cm in silty clay loam soil on an exposed ridge on the leeward side of the volcanically formed Koolau Mountain Range. One carcass was exhumed after 3 weeks, another after 6 weeks, and the last carcass was exhumed after 9 weeks. An inventory of arthropod taxa present on the carrion and in the surrounding soil and observations pertaining to decomposition were recorded at each exhumation. The longer the carrion was buried, the greater the diversity of arthropod species that were recovered from the remains. Biomass loss was calculated to be 49% at the 3‐week interval, 56% at the 6‐week interval, and 59% at the 9‐week interval.     

Customary Homicides in Diyarbakir Province

This study presents an analysis of the causes of so‐called honor killings in the context of “customary homicide” and a discussion of preventive measures. Finalized case files of customary homicide between January 1, 2007 and December 31, 2012 were retrospectively examined in Diyarbakir Province, Turkey. Of a total of 28 case victims, 17 (60.7%) were females and 11 (39.3%) were males. All perpetrators were male. There was a significant difference between male and female victims in terms of economic independence (p = 0.000). A direct blood relationship or relationship by marriage (such as brother‐in‐law) was found to have a significant association with the gender of the victim (p < 0.001). Multilevel educational activities targeting a transformation of the perception of women by society, replacement of patriarchal models with more modern attitudes, and encouragement of individuality may represent effective strategies that may help reduce the number of customary homicide, which represents a multifaceted problem.     

Estimating the preappearance interval from temperature in Creophilus maxillosus L. (Coleoptera: Staphylinidae)

Abstract: Some carrion insects appear on carcasses late in decomposition. While using these late‐arriving taxa to estimate postmortem interval, it is vital to accurately estimate an interval preceding their appearance on a cadaver called the preappearance interval (PAI). This paper tests the possibilities of a PAI estimation from temperature in case of late‐arriving, predatory carrion beetle Creophilus maxillosus. The relationship between temperature and PAI of adult and larval C. maxillosus was modeled using the results of a large‐scale experiment on succession in forests of Central Europe. In both stages, PAI was found to be strongly, inversely related to temperature averaged for the duration of PAI. The PAI estimation from mean degree‐day accumulations (mDDA), estimated DDA, and “PAI*T” functions were tested using external successional data. The greatest accuracy of PAI estimates was achieved using an exponential “PAI*T” function.