The Influence of Clothing and Wrapping on Carcass Decomposition and Arthropod Succession During the Warmer Seasons in Central South Africa*

Abstract: The influence of clothing and wrapping on carcass decomposition and arthropod succession was investigated to provide data to enable estimated postmortem interval in homicide investigations. Six pig carcasses, Sus scrofa, were divided into three sample groups, each with a clothed carcass wrapped and a carcass wrapped with no clothes. Two more carcasses, one with no clothes or wrapping, the other with clothes and no wrapping were used as controls. The clothed or wrapped carcasses had larger visible maggot masses, which moved more freely and these carcasses took longer to dry out. The blow fly maggot masses were dominated by Chrysomya marginalis and Chrysomya albiceps. Oviposition occurred simultaneously on all carcasses. High temperatures in one case caused significant maggot mortality. The Coleoptera community was dominated by Silphidae, Thanathopilus micans larvae, Dermestidae, Dermestes maculatus adults and larvae, and Cleridae, Necrobia rufipes.     

Trichophyton Mentagrophytes Perforates Hair of Adult Corpses in the Gaseous Period*

Abstract: Despite the substantial literature on mycology, there are still limited reports of the interaction between fungi and human hosts in the postmortem period. Thus, the main goal of this study was to investigate the in vitro perforation test using Trichophyton mentagrophytes on hair from adult corpses in the postmortem period (gaseous period). The protocol was carried out with positive (prepubescent children’s hair) and negative controls (healthy adult hair) as well. One strain of Trichophyton rubrum was also used as a negative perforation control. Perforations were found in all the hair samples from corpses and prepubescent children after 12–14 days exposure to T. mentagrophytes and were absent in the hair samples of healthy adults. Furthermore, hair perforation was not observed with T. rubrum. Our preliminary findings suggest the use of T. mentagrophytes as a potential marker of the death interval in forensic science.     

Responses of Lucilia sericata Meigen (Diptera: Calliphoridae) to cadaveric volatile organic compounds

Flies of the Calliphoridae Family are the most forensically important insects because of their abundance on the decedent during the first minutes following death. Necrophagous insects are attracted at a distance by a decomposing body, through the use of volatile chemical cues. We tested the possible attractive role of some volatile organic chemicals (VOCs) released by decaying cadavers, on male and female of Lucilia sericata Meigen (Diptera: Calliphoridae). Two complementary approaches were used. Electroantennography (EAG) allowed identifying the semiochemicals that are detected by the olfactory system of L. sericata. Dose-response tests with EAG showed that dimethyl disulfide (DMDS) and butan-1-ol elicited the highest responses. Behavioral assays showed that, among the VOCs tested, DMDS and butan-1-ol are attractive for L. sericata, while the other VOCs are repulsive or do not cause any behavior. Our results may have potential implications in a better understanding of attractiveness of blowflies toward a corpse.     

Evidence of Premeditation in Skin Messages in Suicide

A 34‐year‐old man with manic‐depressive disorder was found dead sitting in a vehicle with a hose running from the exhaust pipe to the cabin. Numerous suicide notes were found inside his house. At autopsy, the decedent was wearing jeans and a long‐sleeved windcheater. Upon removal of his clothes, a series of messages were also found written on the legs and forearm. Death was due to carbon monoxide toxicity with a blood level of carboxyhemoglobin of 84%. Skin messages represent a rare form of suicide note that may suggest that a suicide has not been planned, as the decedent may have used the nearest surface to write on. This case demonstrates, however, that skin messages may be more organized, being written prior to dressing and setting up the fatal episode. They also may compliment other notes and messages.     

Investigating Residential History Using Stable Hydrogen and Oxygen Isotopes of Human Hair and Drinking Water

The relationship between isotopic signals in human hair and geographic region has potential forensic applications for identifying unknown individuals' place of recent residence. This study analyzes δ²H and δ¹⁸O isotopes in residential tap water and bulk hair samples from 17 volunteers representing 12 locations in Ontario, Canada. There is a strong correlation (R² = 0.9) between δ²H and δ¹⁸O values of the water samples. In contrast, the δ²H and δ¹⁸O values of the hair samples are weakly correlated (R² = 0.3), and the greater variability in the data is linked to dietary factors. This study demonstrates that the δ²H and δ¹⁸O values of hair and drinking water can be used to help identify potential place of residence in forensic cases, particularly in relation to proximity to large bodies of water such as the Great Lakes, but interpretations are complicated by the contribution of both water and diet to δ²H and δ¹⁸O values in hair.     

Fatal Wrong‐Way Collisions on New Mexico’s Interstate Highways, 1990–2004

Abstract: Medical examiner files from 1990 through 2004 were reviewed to identify fatalities caused by drivers traveling the wrong direction on interstate highways and identify risk factors and prevention strategies. Other fatal nonpedestrian interstate motor vehicle crashes served as a comparison group. Data abstracted included decedent demographics, driver/passenger status, seatbelt use, blood alcohol concentration, weather and light at time of occurrence and types of vehicles involved. Of 1171, 79 (6.7%) interstate motor vehicle fatalities were because of drivers traveling against the posted direction in 49 crashes, with one to five fatalities per crash. Wrong‐way collisions were significantly more likely to occur during darkness (p < 0.0001) and involve legally intoxicated drivers (p < 0.0001). In 29/49 (60%) wrong‐way crashes, alcohol was a factor. Prevention strategies aimed at reducing the incidence of driving while intoxicated, as well as improved lighting and signage at ramps, could help reduce the occurrence of fatal wrong‐way collisions on interstates.     

Forces Required for a Knife to Penetrate a Variety of Clothing Types

In stabbing incidents, it is usual for the victim to be clothed and therefore a knife penetrates both clothes and skin. Clothes (other than leather) have been thought to make little difference to the penetration force. However, there is little quantitative data in the literature. In this study, a range of clothes have been tested, either singly or in layers of, for example, T‐shirt and shirt, to quantify the additional force required when clothes are present. A materials testing system has been used to test the penetration force required to stab through clothes into a foam–silicone rubber skin simulant. The results show that the force required can be significantly different, particularly when layers of clothing are penetrated. A cotton t‐shirt adds c. 8 N to the penetration force, while a T‐shirt and jacket can add an additional 21 N. The results allow a more quantitative assessment of forces required in stabbing.     

Artifacts Caused by Leaf-Cutting Ants of the Genus Atta (Hymenoptera: Formicidae): Postmortem Bite Injuries and the Tearing of Clothes

Ants are one of the first insects to find an exposed cadaver and can be present during all stages of decomposition. Although these organisms are not commonly used in postmortem interval estimates, they are to be taken into account on criminal investigations involving human corpses, since they can leave bite marks that can be mistaken for antemortem or perimortem injuries, which could be misleading when ascertaining the occurrence of abuse or physical altercation during a crime. A few studies report the action of ants on human cadavers and even though leaf-cutting ants of the genus Atta are frequently encountered in succession studies that use animal carcasses, there are no records of these fungus-growing species on human corpses. Atta is a genus restricted to the New World, ranging from northern Argentina to southern United States and acts as one of the most conspicuous neotropical herbivores. In this study, we report three cases of violent death that illustrate the impact of ants, especially those of the genus Atta, in a forensic setting. We compare the patterns displayed by postmortem bite injuries caused by leaf-cutter ants and other common species with less robust mandibles. We also present the capability of Atta ants to create artifacts by cutting victim’s clothes in a crime scene, contributing to the knowledge of ant-mediated confounding factors in crime scene investigation.     

Viability of Human Articular Chondrocytes Harvested Postmortem: Changes with Time and Temperature of In Vitro Culture Conditions

Different studies of long‐term chondrocytes viability have shown a gradual reduction as a function of time and ambient temperature. The aim of our in vitro study was to establish chondrocyte postmortem viability curves for 4°C, 11°C, 23°C, 35°C during 63 days after the donors' death. Osteochondral cylinders were procured from the knees of 16 male donors (20–47 years), stored in preservation media that was not changed, and analyzed in 3‐day intervals using a confocal laser scanning microscope. A significant influence of time on viability was found from Day 9 (p = 0.0029) and onwards (p < 0.0001). The lowest overall chondrocyte viability was at 35°C, followed by 4°C (p < 0.0001). The conditions used in this in vitro analysis suggest that similar viabilities may occur while in situ in the decedent. Further studies of chondrocyte viability from individuals with known postmortem intervals may show premise to help evaluate time since death in the late postmortem interval.     

Sex‐ and Size‐Related Patterns of Carrion Visitation in Necrodes littoralis (Coleoptera: Silphidae) and Creophilus maxillosus (Coleoptera: Staphylinidae)

The estimation of postmortem interval (PMI) based on successional patterns of adult insects is largely limited, due to the lack of potential PMI markers. Sex and size of adult insects could be easily used for such estimation. In this study, sex‐ and size‐related patterns of carrion attendance by adult insects were analyzed in Necrodes littoralis (Coleoptera: Silphidae) and Creophilus maxillosus (Coleoptera: Staphylinidae). For both species, abundance of males and females changed similarly during decomposition. A slightly female‐biased sex ratio was recorded in N. littoralis. Females of N. littoralis started visiting carcasses, on average, one day earlier than males. There was a rise in size of males of N. littoralis at the end of decomposition, whereas for females of both species and males of C. maxillosus, no size‐related patterns of carrion visitation were found. Current results demonstrate that size and sex of adult carrion beetles are poor indicators of PMI.     

Insect Successional Pattern of a Corpse in Cooler Months of Subtropical Southeastern Texas

Abstract:  Here, we characterize the cool weather insect fauna found associated with partially skeletonized and desiccated human remains recovered from an abandoned house in an urban area of subtropical, coastal Galveston County, Texas, and use the information to conclude an approximate postmortem interval of 7–10 months. The predominant factors that allow for a confident assessment of the postmortem interval include climatological data, entomological data, and anthropological data. The documented insect fauna represents a unique assemblage present in a particular environment (an urban abandoned house in coastal Texas) at a particular time of year (winter) and includes expected forensically significant insects such as calliphorid flies, muscid flies, and dermestid beetles but also includes less commonly encountered insects such as an unusually dense population of live case-making clothes moths.     

Comparison of Decomposition Rates and Faunal Colonization of Carrion in Indoor and Outdoor Environments

Abstract: Decomposition and insect colonization of pig (Sus scrofa L.) carcasses were observed over a 42‐day period inside and outside a house in a suburban region of Edmonton, Alberta. Three freshly killed pig carcasses were placed outdoors on grass and three carcasses were placed in separate rooms inside a house in a suburban residential area. The carcasses were examined and sampled regularly. Outside carcasses were colonized rapidly by Calliphora vicina (R‐D), Lucilia sericata (Meigen), Lucilia illustris (Meigen), Eucalliphora latifrons (Hough), Cynomya cadaverina (R‐D), Phormia regina (Meigen), and Protophormia terraenovae (R‐D). There was a delay of 5 days before inside carcasses were first colonized but all species except E. latifrons and L. illustris readily colonized at this time. Many more insects colonized the outside carcasses, and these were rapidly skeletonized. Inside, much fewer insects were present and decomposition was slowed and colonization extended. Dispersal patterns of postfeeding larvae inside the house on hard substrate were greatly expanded compared with those from carcasses on grass.     

An Analysis of Human Skeletal Remains with Cerebral Palsy: Associated Skeletal Age Delay and Dental Pathologies*

Abstract: In 2002 the authors were asked to examine the skeletal remains of an individual with a known history of severe cerebral palsy (CP) who was 21–23 years old at death. Skeletal age estimates of 11–15 years and dental age estimates of c. 16 years are younger than the known age of the decedent. Skeletal analysis also identified dental pathologies such as chronic tooth grinding and substantial calculus deposits. Scarce literature exists on forensic human remains cases with CP, and this study contrasts the age discrepancy and other features of this case with typical clinical characteristics of CP. A review of the CP literature suggests that delayed skeletal maturation and dental pathologies such as those observed in this case are indicative of complications related to CP. This article may alert future investigators to some of the osteological signs of CP and the probability that age indicators may be misleading.     

Positional Asphyxia in Opioid-Related Deaths: Is It Being Overlooked?

The contribution of positional asphyxia in opioid-related deaths is currently unknown. Diagnostic criteria for positional asphyxia include finding the decedent in a position that does not allow for adequate respiration and an inability to extricate themselves from the position due to various conditions. Our primary objective was to assess whether positional asphyxia and the resulting airway compromise were a contributing factor to death due to the toxic effects of opioids. We evaluated 225 deaths where the death scene investigation contained adequate information to evaluate for positional asphyxia and performed a Pearson chi-square test to determine if the proportion of deaths found in an airway compromising position was higher when opioid(s) caused the death. The proportion of decedents found in a potential airway compromising position was greater when the death was related to opioid use (p < 0.0001). Further, narrowing the dataset to decedents who were definitely in an airway compromising position [Yes (24.49%) vs. No (11.02%)] showed a statistically significant association between positional asphyxia and deaths related to opioid use (p = 0.0021). Carefully documenting the position in which the decedent was initially found may be a significant factor in accurate reporting and in harm reduction efforts to decrease the opioid mortality rate.     

Temperature‐dependent Development of Parasarcophaga similis (Meade 1876) and its Significance in Estimating Postmortem Interval

Flesh flies are commonly found insects on decaying corpses that appears slightly later than blowflies, and their development patterns are significant indicators for minimum postmortem interval (PMI_min) estimation. In this study, the flesh fly Parasarcophaga similis (Meade 1876) was reared at nine constant temperatures ranging from 15°C to 35°C to examine indicators for estimating their age. We generated three development models, including isomorphen diagram, isomegalen diagram, and thermal summation model. Larval body length at different rearing temperatures was fit into an L = a + bT + cT² + dT³ equation with which the relationship between the larval body length (L) and the time after larviposition (T) was confirmed. The pupal stage was categorized into 13 substages according to intrapuparial morphological changes, and a detailed table was generated of the pupal developmental stages at five rearing temperatures, 15°C, 20°C, 25°C, 30°C, and 35°C. This study provides fundamental data in supporting P. similis as an indicator for PMI_min estimation.     

Atropine Eye Drops: An Unusual Homicidal Poisoning

In March 2009, the body of a 51‐year‐old man was found in the boot of his car. The body had been frozen before being dismembered at the abdomen. The autopsy failed to determine the cause of death. Systematic toxicological analyses of the victim's peripheral blood and urine showed the presence of atropine, a powerful anticholinergic. Atropine was therefore specifically detected and quantified throughout the victim's biologic samples by HPLC‐MS² in the biologic fluids and UHPLC‐MS² in the hair. The atropine concentrations were 887 ng/mL in the cardiac blood, 489 ng/mL in the peripheral blood, 6693 ng/mL in the gastric contents (1.1 μg), 6753 ng/mL in the urine, and 2290 pg/mg in the hair. The blood concentrations measured in the decedent were consistent with an overdose of atropine, which was determined as the cause of death. The manner of death was a homicide with criminal intent.     

Field Study on the Attraction and Development of Insects on Human Meconium and Breast‐fed‐Infant Feces

Urogenital myiasis of newborn infants, although rare, is usually considered to indicate neglect due to attraction of flies to feces; however, infant feces have not been determined to attract insects. Human meconium and breast‐fed‐infant feces were used to determine attractiveness to insects and to examine subsequent colonization and growth patterns of insect larvae. Despite small amounts of fecal material present, adults of Lucilia sericata arrived at breast‐fed‐infant feces within five minutes; insects were rarely observed on meconium. Oviposition and growth of L. sericata larvae occurred only on breast‐fed‐infant feces; however, the larvae did not progress beyond the second instar. These data suggest that urogenital myiasis by L. sericata in newborn human infants within the first few days postpartum would not be expected, but desiccation and depletion of infested feces may provide a possible pathway for urogenital myiasis in older newborn infants.     

Differentiation of Morphologically Similar Human Head Hairs from Two Demographically Similar Individuals Using Amino Acid Ratios,

Human hair is frequently encountered as forensic evidence and can contribute valuable information to investigators. Conventional forensic hair analyses include microscopic hair comparison (MHC) and DNA analysis. However, MHC is not supported by statistics and DNA analysis cannot always be performed. Recent studies have demonstrated that evaluation of differences in the hair proteins may offer an alternate method to these analyses. In this study, an evaluation of the amino acids present in hair was investigated as an approach to differentiate morphologically indistinguishable hair samples from two demographically similar individuals. Proteins in the hair were digested using hydrochloric acid, and the resulting amino acids were derivatized with N,O-Bis(trimethylsilyl)trifluoroacetamide (BSTFA) for analysis using gas chromatography-mass spectrometry (GC-MS). Eight derivatized amino acids were detected and quantified relative to an internal standard, L-norvaline, and used to construct twenty-eight amino acid ratios. Hair samples were collected from four areas of the head on various days over the course of one month, and no significant differences in amino acid ratios (p-value > 0.05) were observed among the areas of the head, and the ratios were consistent over the time period of this study. Additionally, fifteen of these amino acid ratios were found to be significantly different between the two individuals when compared using a two-sample t-test (p-value ≤ 0.05). These data indicate that amino acid analysis was able to differentiate two morphologically similar hair samples from different individuals and demonstrates the applicability of this method to distinguish similar hair samples when DNA analysis cannot be performed.     

Forensic Entomology and the Estimation of the Minimum Time Since Death in Indoor Cases

Eight cases that occurred indoors in which the insects played an important role in the mPMI estimation are presented. The bodies of socially isolated people and old people living alone were discovered in central Italy between June and November. mPMI ranged from a few days to several weeks. Insects were collected during the body recovery and the postmortem. Climatic data were obtained from the closest meteorological stations and from measurements performed on the site. Sarcophagidae and Calliphoridae species were present in 75% of the cases with Lucilia sericata and Chrysomya albiceps collected in 50% of the cases. Chrysomya albiceps was always found in association with Lucilia species. Scuttle flies (Phoridae) were found in 37.5% of the cases, confirming the ability of these species in indoor body colonization. We show that if sealed environment may delay, the insect arrival dirty houses may create the environment where sarcosaprophagous insects are already present.