9.4: Forensic Taphonomy and Clandestine Grave Detection

Forensic taphonomy is the study of what changes occur to a body between the time of death and the moment of discovery, also known as the postmortem process, in order to draw conclusions for courtroom purposes. Although closely related to forensic anthropology, forensic taphonomy is more focused on the decomposition process whereas forensic anthropology is specifically interested in the skeletal remains of the body. What both sciences have in common is the analysis of trauma and the systematic approach to a reconstruction of the death event, which includes preservation of the remains, observation of the remains within the environment, and the recovery of the remains. Both sciences would earn an entire chapter themselves; however, for the purpose of forensic entomology, we must explore what both sciences do exceptionally well: finding decomposed bodies, surface skeletons, and clandestine graves. We have discussed at length in this chapter the discovery and processing of scenes containing bodies in various stages of decomposition. Let us turn our attention to surface skeletons. Skeletal remains discovered on the surface will either be intact or scattered. It is not uncommon to find a skeletal skull many yards from the rest of the body as once detached from the neck, they tend to roll when in a downhill orientation, or with the run-off from rainfall, or the activity of animals. Animals alone are capable of scattering bones up to 100 yards from the scene. Bones that have been subjected to the environment for lengthy periods of time may take on the appearance of natural material like sticks, rocks, or other stone features. Furthermore, if recognized as bone, a determination must be made if the bones are of a human or an animal, which may require the analysis of an anthropologist. Once the bones are confirmed as human, a systematic search for the entire skeleton should be conducted using the grid-pattern search method. Documentation of the scattered bones should also be completed with the bones in situ within each grid. The bones can then be collected and reassembled following proper crime scene processing procedures, paying careful attention to the detritus of insect and arthropod activity. Clandestine graves are those that are not officially recorded and are generally used to dispose of a body following a criminal act. These graves are most often located in remote outdoor wooded or desert areas or in the basements or gardens of occupied or unoccupied houses or buildings. These graves are generally hand-dug, shallow, and of an irregular shape. Clandestine graves in building basements can be very difficult to find; especially if a layer of stone or concrete has laid or poured on top of the grave. Ground Penetrating Radar (GPR), which use radar pulses directed downward into the ground, have some success as a non-obtrusive means of body detection, as well as the use of cadaver canines. It is important to know that most commercial GPR systems are not calibrated to detect gravesites, and therefore some software adjustments are required. Cadaver canines are also useful in outdoor grave detection, but equally useful is the trained eye of a taphonomist or anthropologist. The common Hollywood belief is that all clandestine graves will have irregularly shaped depressions that can be detected by the average novice. Although some depression may occur as a result of body decomposition, the rate of depression will be slow and often indistinguishable. In wooded or grassy areas, the vegetation on top of the grave may be more vigorous because the soil has been loosened and aeriated during the digging process. Paw marks from wild animals might be detectable, as well as rodent burrows. Once discovered, the gravesite must be meticulously documented and processed layer by layer until the body is fully uncovered. Once uncovered, the body is examined, documented, and recovered following proper crime scene processing procedures, paying particular attention to entomological evidence of insect activity. Once the body is removed from the grave, the soil beneath the body must also be examined and processed, as well as any dirt below the body until the hard pan level has been reached.