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How water monitors, or ‘kabaragoya’, can help locate dead bodies 

28 Jul 2022

BY Ruwan Laknath Jayakody The water monitor is a medico-legally significant animal and is important specifically in forensic death investigations, as its presence can be helpful in locating a missing body, and by the same token, since they can affect death scene findings, it is necessary to interpret post-mortem features in such cases cautiously. These observations were made in case reports on “Water monitors: Implications in forensic death investigations“ which was authored by K.M.T.B. Gunethilake (Consultant Judicial Medical Officer at the Provincial General Hospital, Ratnapura) and M. Vidanapathirana (Professor at the Department of Forensic Medicine of the Faculty of Medical Sciences of the University of Sri Jayewardenepura) and published in Medico-Legal Journal of Sri Lanka 4(2) in December 2016. Outdoor post-mortem animal scavenging is, J.B. Weeraratna, S. Amararatne, R.A.S.K. Ranasinghe, and M. Vidanapathirana’s “Indoor post-mortem animal scavenging – A case report“ noted, encountered frequently, while P. Saukko and B. Knight’s “Post-mortem damage by predators” noted that predators vary from ants to foxes, bluebottles, and monitor lizards.  Among them, post-mortem scavenging by water monitors, C. Traeholt’s “Notes on the water monitor (Varanus salvator) as scavenger” mentioned, is not uncommon. As pointed out in a study conducted on the Indonesian island of Sumatra, the water monitor is a large lizard native to Southeast Asia and is 1.5-2 metres in size. They live close to water.  The subspecies of V. salvator salvator, commonly called the “Kabaragoya” is, per “Family Varanidae (Monitor lizards)”, limited to Sri Lanka and is found in every environment with adult water monitors found in drier forests while young water monitors frequently live in the vicinity of rivers. They are efficient carnivores and scavengers and eat dead bodies found in any environment, irrespective of whether they are on the ground or in the water, and thereby cause many effects on forensic death investigations. Further, the post-mortem scavenging of outdoor dead bodies by water monitors is not uncommon in day-to-day forensic practice. Case report: One A woman went missing and was suspected of being disposed of in the water. A vigorous search was done by hundreds of villagers and the Navy. The body was ultimately recovered from a river due to the abundance of water monitors attracted to the scene, thus indicating the site of the dead body.  The body was in a moderate state of putrefaction. There were multiple, almost parallel tears and cuts in addition to the large losses of flesh with teeth marks. Injuries on the limbs simulated cut injuries. However, the skull bones had a depressed through and through slashed cut. The cause of death was head injuries due to sharp force trauma. Case report: Two  The site of the dead body was identified in a growing paddy field when searched along the path formed by the water monitors. The body was in a moderate state of putrefaction and had tears, cuts, and teeth marks on the body. The neck injuries simulated a cut throat. However, there was damage and the loss of internal organs, and the cause of death was unascertainable. Water monitors prefer a fresh carcass to a rotten one. The effects of water monitors on forensic death investigations are vast as they affect the scene, the body and the findings of the autopsy. It is not always disadvantageous as in certain circumstances, they are useful in identifying the site of disposal of the dead body. When bodies are disposed of in the water, they are difficult to find. But water monitors are sensitive to smell and are attracted to the body early. They follow a scent trail and smell a rotten carcass up to 100 metres away. Irrespective of whether it is on the ground or in the water, they are attracted to the scene. However, according to Traeholt, they only feed on carrion if found within their home range. Per B.A. Young, J. Dumais, N. John, B. Lyons, A. Macduff, M. Most, N.A. Reiser, and P.J. Reiser’s “Functional segregation within the muscles of aquatic propulsion in the Asiatic water monitor”, water monitors swim using their long tails.  In the first case, a woman was killed and hidden in the water, and even though a vigorous search was done, the body was ultimately recovered from a river due to the abundance of water monitors attracted to the scene. In the second case, the body was recovered from a growing paddy field when searched along the path formed by the water monitors.  As explained in D. Ritter’s “Axial (the muscles of the tail, trunk, and eyeballs) muscle function during lizard locomotion”, water monitors can move fast and steadily, even in muddy locations, because of the lateral bending during locomotion which stabilises the trunk. Water monitors affect death scene findings too. They are relatively large animals and because of their movements at the scene and due to dragging items or the body away from the original locus, the scene is converted into one that is suspicious. Further, dealing with water monitors at the scene can sometimes be a terrifying experience for forensic pathologists, even though water monitors are not very harmful. The importance of water monitors in forensic death investigations in Sri Lanka was first reported in the authors’ “Water monitors: Importance in forensic death investigations”. The post-mortem injuries caused by water monitors can affect the interpretation of the autopsy findings. Those post-mortem artefacts, M.A. Rothschild and V. Schneider’s “On the temporal onset of post-mortem animal scavenging. ‘Motivation’ of the animal” elaborates, can simulate anti-mortem injuries and therefore, the differentiation of post-mortem injuries from ante-mortem injuries is important.  In both the above cases, the presence of multiple, almost parallel tears with no vital reaction were compatible with animal predation and the severity of the cuts and the presence of water monitors around the scene suggested that those were teeth and claw injuries of water monitors. They have sharp claws which insert post-mortem artefacts like incised injuries or stabs.  Further, in the second case, the areas with large tissue losses such as in the neck were accompanied by teeth marks. Though the injuries of the limbs in the first case simulated cut injuries and injuries on the neck in the second case simulated a cut throat, the presence of the associated teeth and claw marks helped, per Saukko et al., to differentiate and identify them as post-mortem animal bites.  Further, the identification of ante-mortem injuries among post-mortem animal injuries is also important, especially to ascertain the cause of death. There are, per Saukko et al., no vital signs such as active haemorrhage in the wound margin and reddening or oedema (build-up of fluid in the body which causes the affected tissue to become swollen) of the edges in post-mortem injuries.  In the first case, since it had a deep slashed cut in the head with an underlying depressed, through and through skull cut, it indicated an ante-mortem chop with a sharp, long, heavy, hard and rigid weapon such as a manna (knife) or sword. However, since the body was in a state of moderate putrefaction and was recovered from the water, this scalp cut did not show vital reactions and simulated post-mortem animal bites.  Therefore, when differentiating ante-mortem and post-mortem injuries, internal injuries should also be considered. Hence, the cause of death in the first case was ascertained as a head injury due to sharp force trauma. As seen in both cases, water monitors eat away flesh and tear off clothing, thus making identification difficult. They breach the skin barrier, enhancing putrefaction by facilitating the invasion of microorganisms and maggots. Most importantly, they eat internal organs, making the decision on the cause of death difficult and histopathology (the diagnosis and study of diseases of the tissues) impossible.  In some of the cases, it has been observed that all the chest organs have been eaten by water monitors entering through the thoracic outlet (the space between the collarbone/clavicle and the first rib, which is a narrow passageway filled with blood vessels, nerves, and muscles). Similarly, in the second case, the cause of death was unascertainable especially due to post-mortem animal predation. The flesh of the water monitor is not consumed due to a local cultural belief that its flesh is highly poisonous. Further, there is another belief that the oil extracted from them is used for deliberate poisoning.  As injuries caused by water monitors may result in artefacts and since they move objects from the scene and in turn convert them into one that is suspicious, this makes injury interpretation and identification difficult while posing challenges to the ascertaining of the cause of death.


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