Modelling the buried human body environment in upland climes using three contrasting field sites

Despite an increasing literature on the decomposition of human remains, whether buried or exposed, it is important to recognise the role of specific microenvironments which can either trigger or delay the rate of decomposition. Recent casework in Northern England involving buried and partially buried human remains has demonstrated a need for a more detailed understanding of the effect of contrasting site conditions on cadaver decomposition and on the microenvironment created within the grave itself. Pigs (Sus scrofa) were used as body analogues in three inter-related taphonomy experiments to examine differential decomposition of buried human remains. They were buried at three contrasting field sites (pasture, moorland, and deciduous woodland) within a 15 km radius of the University of Bradford, West Yorkshire, UK. Changes to the buried body and the effect of these changes on hair and associated death-scene textile materials were monitored as was the microenvironment of the grave. At recovery, 6, 12 and 24 months post-burial, the extent of soft tissue decomposition was recorded and samples of fat and soil were collected for gas chromatography mass spectrometry (GCMS) analysis. The results of these studies demonstrated that (1) soil conditions at these three burial sites has a marked effect on the condition of the buried body but even within a single site variation can occur; (2) the process of soft tissue decomposition modifies the localised burial microenvironment in terms of microbiological load, pH, moisture and changes in redox status. These observations have widespread application for the investigation of clandestine burial and time since deposition, and in understanding changes within the burial microenvironment that may impact on biomaterials such as hair and other associated death scene materials.     

Cadaver dog and handler team capabilities in the recovery of buried human remains in the southeastern United States

The detection of human remains that have been deliberately buried to escape detection is a problem for law enforcement. Sometimes the cadaver dog and handler teams are successful, while other times law enforcement and cadaver dog teams are frustrated in their search. Five field trials tested the ability of four cadaver dog and handler teams to detect buried human remains. Human and animal remains were buried in various forested areas during the summer months near Tuscaloosa, Alabama. The remains ranged in decomposition from fresh to skeletonized. Cadaver dogs detected with varying success: buried human remains at different stages of decomposition, buried human remains at different depths, and buried decomposed human and animal remains. The results from these trials showed that some cadaver dogs were able to locate skeletonized remains buried at a significant depth. Fresh and skeletonized remains were found equally by the cadaver dogs along with some caveats. Dog handlers affected the reliability of the cadaver dog results. Observations and videotape of the cadaver dogs during field trials showed that they were reliable in finding buried human remains.     

Effects of processing techniques on the forensic DNA analysis of human skeletal remains

Human remains processed by forensic anthropologists may potentially be used for genetic analysis. Therefore, the condition of the deoxyribonucleic acid (DNA) in processed remains may become an issue for future analysis. Processing techniques employed by anthropologists are highly variable and scanning electron microscopy reveals significant alterations to the bone surface depending upon the technique used. Such damage to the bone indicates differences may exist in quality and quantity of DNA extracted. This study assessed how five processing procedures used by major forensic anthropology laboratories around the country affects the amounts of DNA extracted from human rib bones and the subsequent DNA analysis. The DNA was analyzed using the short tandem repeat (STR) locus CSF1PO and amelogenin. The findings indicate processing procedures used by forensic anthropologists do not adversely affect DNA analysis but prolonged exposure to heat during processing may decrease the yield of information from the DNA.     

Detection of human proteins in buried blood using ELISA and monoclonal antibodies: towards the reliable species indentification of blood stains on buried material.

The survival of human proteins in blood stains on fragments of cloth buried in exposed soil was examined in a 15-month investigation carried out from September 1990 to December 1991. During this period there was a wide variety of weather conditions. Samples were exhumed at 4-weekly intervals for 16 weeks and finally at 65 weeks; extracts of the stains were tested for albumin and IgG using a highly specific and sensitive enzyme-linked immunosorbent assay (ELISA) performed with monoclonal antibodies. Human albumin survived well throughout the 15 months of study, but IgG could be detected only in the 4- and 8-week samples. The reactions for IgG were weaker than those for albumin, although the method's sensitivity (10 ng) was the same for each protein. Appropriate buried and non-buried control experiments were carried out using cloth, either unstained or stained with human blood or animal sera; there was no cross-reactivity between human and the other species investigated and soil did not affect the assay; under laboratory conditions, IgG and albumin survived equally well. The system's versatility was illustrated by using monoclonal anti-bovine-albumin to detect specific albumin in the extracts of buried cloth which has been stained with bovine serum. It was concluded that ELISA performed with monoclonal antibodies could be of great value in identifying blood stains for forensic purposes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Individual age determination using growth rings in the cementum of buried human teeth

Incremental lines of the dental cementum were used for individual age determination in 102 teeth. 66 of them come from different historic periods, 15 teeth were cremated. 36 modern teeth of known age were use as controls. The incremental lines were investigated by use of 100 microns thin cross-sections of the root. Age determination by this method was possible in every tooth, independent of incinaration of various burial conditions. The individual age was determined by adding the mean value of the repeatedly counted incremental lines to the sex-specific eruption age of the tooth in question. Since average deviation from known age is +/- 3.23 years only, counting the incremental lines represent a very advantageous, quantitative method for individual age determination.     

Analysis of an ancestry using cremated old human remains from the Korean War victims

Analysis of DNA from burnt bone fragment is the very hard work for the human identification in forensic casework. In general, cremated bone with an artificial damage is more difficult to get an intact DNA than a singed one because of the chemical and biological drastic changes such as protein denaturation and destruction. In this study, we pursue the best technical approach for the minimal damage and the contamination of DNA from other factors in the preconditioning and the extraction process based on over 70 years old Korean War victim skeletal that was burnt and buried in Korean Peninsula. First of all, we removed the pollutant and the dust from the burnt bones using dental instruments, and then incubated with EDTA buffer at 25 ℃ to remove inhibitors such as calcium and mineral. In order to compare the DNA preservation ability between a pellet and a supernatant, samples are repeatedly tested to collect washed EDTA buffer several times to separate. Each of isolated materials is secondly cleaned with the organic extraction method using phenol and analyzed mtDNA sequence with the in-house method for the ancestry assay. The better discrimination ability was appeared in the supernatant than the pellet. Nevertheless, many of the forensic geneticists use a powdering method for getting more DNA, we applied EDTA buffer in the preconditioning step to eliminate every contamination. As a result, the contamination factor was efficiently removed and the ancestry was estimated as per the written information. Consequently, cremated bone is identified to belong in the D4 mtDNA haplogroup which is commonly reported in ethnic groups in Asia especially Korea. This is a preliminary study of a human identification over an ancestry analysis to give information against a mass disaster in a future. Through a higher process optimization and better analytical methods toward more remains, which are genetically difficult to analyze, will support to examine the identity of the post cremated remains.     

The "coffin fly"Conicera tibialis (Diptera: Phoridae) breeding on buried human remains after a postmortem interval of 18 years

The "coffin fly,"Conicera tibialis Schmitz (Order: Diptera, Family: Phoridae), is well known for its frequent occurrence on buried corpses, in some cases after postmortem intervals of even 3-5 years. The present report describes the presence of a large amount of individuals of C. tibialis inside the coffin of a buried human corpse exhumed 18 years after death in central Spain. Adults, some of them newly emerged, and empty puparia were found in connection with the remains. Such postmortem interval is significantly longer than previously known for this species and raises the question on the current state of knowledge about the use of insects for estimating the postmortem interval in old, buried remains.     

Highly efficient and automated extraction of DNA from human remains using a modified EZ1 protocol

Bones and teeth often represent the only sources of DNA available for identifying human remains. DNA in bones and teeth is generally better preserved than that in soft tissues because of the presence of hard connective tissue with a high level of calcium. Because of the extensive mineralisation, the choice of an efficient DNA extraction procedure is important to minimise the sampling of a high level of minerals and to remove polymerase chain reaction (PCR) inhibitors. Some protocols are available for DNA extraction from bones and teeth as part of the Qiagen EZ1 DNA Investigator Kit using the EZ1 Advanced XL automated purification platform. To improve the efficiency of DNA extraction from skeletal remains, the present study focuses on a modification to these already available protocols. In this study, different bones and teeth collected between 1 and 50 years after death were subjected to DNA extraction using the standard EZ1 protocol, a supplementary protocol, and a modified protocol. The modified approach included a decalcification step, whereas the Qiagen protocols worked directly on non-decalcified powder. In all three procedures, 150 mg samples were used for DNA extraction. We evaluated the quantity of DNA recovered from samples, the presence of any PCR inhibitors co-extracted, the level of DNA degradation, the quality of short tandem repeat (STR) profiles, and the reproducibility of the modified procedure. When compared with the other protocols, the modified protocol resulted in the best recovery of DNA that was free of PCR inhibitors. Additionally, the STR profiles were reliable and of high quality. In our opinion, the decalcification step increases DNA recovery by softening tissues, which allows lysis solutions to act more effectively. Furthermore, the use of two lysis solutions and the variation added to the EZ1 purification step allow for DNA recovery with quality and quantity superior to those of the previously available Qiagen-based protocols. These findings may be helpful solutions to the problems commonly encountered when dealing with difficult samples, such as bones and teeth.

Key points

• Bones and teeth often represent the only sources of DNA for identifying human remains.
• The choice of an efficient DNA extraction procedure is important for maximizing DNA recovery and removing PCR inhibitors.
• This study focuses on modifications to the previously available Qiagen-based protocols.
• The modified protocol enabled the best recovery of DNA, and both quality and quantity were superior to those of the previously available Qiagen-based protocols.
• The STR profiles obtained from samples extracted using the modified protocol were reliable and of high quality.

     

Characterization of the volatile organic compounds present in the headspace of decomposing animal remains, and compared with human remains

Human Remains Detection (HRD) dogs can be a useful tool to locate buried human remains because they rely on olfactory rather than visual cues. Trained specifically to locate deceased humans, it is widely believed that HRD dogs can differentiate animal remains from human remains. This study analyzed the volatile organic compounds (VOCs) present in the headspace above partially decomposed animal tissue samples and directly compared them with results published from human tissues using established solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) methods. Volatile organic compounds present in the headspace of four different animal tissue samples (bone, muscle, fat and skin) from each of cow, pig and chicken were identified and compared to published results from human samples. Although there were compounds common to both animal and human remains, the VOC signatures of each of the animal remains differed from those of humans. Of particular interest was the difference between pigs and humans, because in some countries HRD dogs are trained on pig remains rather than human remains. Pig VOC signatures were not found to be a subset of human; in addition to sharing only seven of thirty human-specific compounds, an additional nine unique VOCs were recorded from pig samples which were not present in human samples. The VOC signatures from chicken and human samples were most similar sharing the most compounds of the animals studied. Identifying VOCs that are unique to humans may be useful to develop human-specific training aids for HRD canines, and may eventually lead to an instrument that can detect clandestine human burial sites.     

Occurrences of flesh flies (Diptera: Sarcophagidae) on human cadavers in Switzerland, and their importance as forensic indicators

From 1993 to 2008, criminal investigations were conducted in the western part of Switzerland with special attention to blowfly and flesh fly species in order to estimate the post-mortem interval when requested by the police authorities. Flesh flies were found in only 33 cases out of 160. Five species of the genus Sarcophaga were identified (S. africa, S. argyrostoma, S. caerulescens, S. similis and S. sp.). The main species found on corpses (larval stage) was S. argyrostoma. The thermal constant (K) calculated for this species in Switzerland is 380.6 ± 16.3 (mean ± S.D.) degree-days. With the exception of S. caerulescens, found three times in the larval stage on corpses, the three other species are of minor forensic importance. S. argyrostoma is found during summer and indoors. This species colonises dead bodies, usually the same day as blowfly species, and it could be used to estimate the post-mortem interval. Other species are discussed in the light of current knowledge on their biology and ecology. It is recommended that voucher material be deposited in a museum, allowing further studies by relevant specialists, thereby helping investigators and avoiding misidentifications.     

Accuracy of developing tooth length as an estimate of age in human skeletal remains: the deciduous dentition

Dental age assessments are widely used to estimate age of immature skeletal remains. Most methods have relied on fractional stages of tooth emergence and formation, particularly of the permanent dentition, for predicting the age of infants and very young children. In this study, the accuracy of regression equations of developing deciduous tooth length for age estimation (Liversidge et al.) is tested on a sample of 30 Portuguese subadult skeletons of known age at death. Overall the method shows high accuracy and the average difference between estimated and chronological age is between 0.20 and -0.14 years when using single teeth, and 0.06 years, when using all available teeth. However, there is a tendency for the deciduous molars to provide overestimates of chronological age. Results show that age estimates can be obtained within +/-0.10 years with a 95% confidence interval when several teeth are used. Overall between-tooth agreement in age estimates decreases with increasing age but there is less variability of estimates with more teeth contributing to overall mean age. One seemingly limitation of this method may be the fact that it was developed by combining the maxillary and mandibular teeth. The other is related to the accuracy with which radiographic tooth length can be used as a valid surrogate for actual tooth length. Nevertheless, the advantages of this metric method surpass the limitations of chronologies based on stages of dental development.     

Human remains sold to the highest bidder! A snapshot of the buying and selling of human skeletal remains on eBay, an Internet auction site

Internet auction sites have become increasingly popular, with diverse items up for sale to the public worldwide. The purposes of this paper are to inform the forensic community that human skeletal remains, old and new, are for sale on the eBay internet auction site, and to advise forensic scientists that eBay does not use a forensic anthropologist to assess photographs of these materials. Over the last few years, this website was "surfed," with numerous auctions during this period. After contacting eBay by email, representatives responded that they adhere to Native American Grave Protection and Repatriation Act (NAGPRA) and that their website indicates that auctions must state that sale of human remains is for instructional purposes only. Based on the photographs, the remains appear to be of prehistoric and modern origin. An unfortunate consequence of such sale may generate interest in stealing remains from graves, mortuaries, hospitals, or county morgues worldwide.     

Role of orthopedic implants and bone morphology in the identification of human remains

When conventional methods of identification, such as visual recognition and dental comparison, cannot be used to identify a deceased person, it becomes necessary to consider alternative methods. The presence of an orthopedic implant in a body may assist identification if ante-mortem medical records are available for comparison. Another method of identification involves comparison of ante-mortem and postmortem radiographs. Eight cases are reported from Forensic Science SA where the presence of orthopedic implants and/or ante-mortem radiographs were used to try to establish identification. In six cases, positive identification was established, and in two cases with upper limb orthopedic implants, the bones remained unidentified. Manufacturers were unable to provide any information about the distribution and use of the implants that could be of use with identification, as there are no requirements in Australia for individual medical implants to be tracked. Such a system has the potential to aid postmortem identification if serial codes were etched onto implants that could then be traced to manufacturers, surgeons, and recipients of these devices.     

Cytokinetics of epidermic cells in skin from human cadavers. I. Dependency on the postmortal interval

Punch biopsies taken from the extensor side of the thigh of 35 human cadavers were incubated in vitro with radioactively labeled thymidine (3H-thymidine = 3H-TdR, 14C-thymidine = 14C-TdR) to determine whether a relationship exists between changes in the proliferative activity of the skin and the postmortal interval after irreversible cardiac arrest. The cadavers were stored at 4 degrees C. Cadavers with indeterminable time of death or presence of intoxication, drug therapy with cytostatic agents, or a skin disease were excluded from the study. Single, double, or multiple biopsies were performed on the same cadaver; single labeling with 3H-TdR was done in all cases; double labeling with 3H-TdR and 14C-TdR in selected cases. No relevant changes in the labeling index (mean, 2.39 +/- 1.03%) were demonstrable within the examined postmortal interval of 77.75 h. The DNA synthesis time (ts) was, on the average, 4.75 +/- 1.44 h; a certain relationship to the postmortal interval existed since ts declined with increasing storage time. The potential doubling time (tpot) decreased accordingly, beginning with 181.7 h (mean storage time, 29.9 h) and ending with 137.7 h (mean storage time, 41.7 h). No statistically relevant differences, however, were established at the 1% level. Whereas both labeling index and tpot during the early postmortal interval are comparable with observations in live humans, ts was relatively short as compared to that for the epidermis of live humans.     

Identification of human skeletal remains by comparison of bony details of the cranium using computerized tomographic (CT) scans

A case is described where a cranium from an unknown individual is identified by comparison of antemortem and postmortem computerized tomographic (CT) images of the bony structure of the skull. While on at least one occasion CT scans of individual cranial landmarks have been used to identify unknown remains, this study is remarkable because positive identification of a deceased individual was accomplished by performing a CT scan on an unidentified cranium and comparing multiple landmarks and images with corresponding features in an antemortem CT scan of a missing man. Bony details of the frontal and sphenoid sinuses, ethmoid and mastoid air cells, sagittal cranial suture, and the torcula (the internal occipital protuberance) were exactly the same on both CT scans, confirming them as the same person.     

Scavenging behavior of Lynx rufus on human remains during the winter months of Southeast Texas

Animal-scavenging alterations on human remains can be mistaken as human criminal activity. A 32-day study, documenting animal scavenging on a human cadaver, was conducted at the Southeast Texas Applied Forensic Science facility, Sam Houston State University, Huntsville, Texas. A Stealth Cam Rogue IR was positioned near the cadaver to capture scavenging activity. An atypical scavenger, the bobcat, Lynx rufus, was recorded feeding on the cadaver. Scavenging by bobcats on human remains is not a predominant behavior and has minimal documentation. Scavenging behaviors and destruction of body tissues were analyzed. Results show that the bobcat did not feed on areas of the body that it does for other large animal carcasses. Results also show the bobcat feeds similarly during peak and nonpeak hours. Understanding the destruction of human tissue and covering of the body with leaf debris may aid forensic anthropologists and pathologists in differentiating between nefarious human activity and animal scavenging.     

Evaluation of the 190H analogues of prostaglandins E1, E2, F1 alpha and F2 alpha as specific markers for the identification of human semen in body fluid mixtures

The specificity of antisera raised against each of the prostaglandin series 190H E1/E2 and 190H F1 alpha/F2 alpha, produced in males, was evaluated by radioimmunoassay. Further, the ability of these antisera to detect semen specific prostaglandins in mixtures of body fluids was examined. Antisera directed against the 190H E1/E2 series cross-reacted with prostaglandin E1 and marginally with E2. Antisera raised to the 190H F1 alpha/F2 alpha series were, however, highly specific to the semen specific prostaglandins 190H F1 alpha/F2 alpha and 190H E1/E2. It was possible to detect picogramme quantities of contaminating 190H F1 alpha/F2 alpha on vaginal swabs taken up to 72 h after intercourse and on vaginal swabs stored at room temperature for up to 2 years. These prostaglandins were not detected on semen free vaginal swabs, in faecal material, saliva, urine or in a sample of human milk (stain). A limited study of casework material is also described. Detection of the 190H F series, as a group, has considerable potential in the identification of human semen at picogramme levels, eliminating the need for alternative chemical tests and extensive microscopic examination.