Journal of Forensic Science and Medicine

CASE REPORT
Year
: 2022  |  Volume : 8  |  Issue : 3  |  Page : 114--117

Differentiating postmortem claw marks by the Asian water monitor (kabaragoya) from antemortem sharp weapon trauma based on the injury pattern


Piumi Dileka, Chiranthika Madhupoorni A. Gunathilaka, Thilinika Ranchamali, Sameera A Gunawardena 
 Department of Forensic Medicine and Toxicology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka

Correspondence Address:
Chiranthika Madhupoorni A. Gunathilaka
Department of Forensic Medicine and Toxicology, Faculty of Medicine, University of Colombo, No 25, Kynsey Road, Colombo 00800
Sri Lanka

Abstract

The Asian water monitor (Varanus salvator) or kabaragoya is the predominant large animal scavenger of human remains in Sri Lanka; however, its significance is rarely discussed in the forensic literature. This is the case of a 54-year-old male with a history of dementia, depression, and wandering behavior whose body was found, partially submerged in a river, 2 days after he was reported missing. There were several linear wounds with regular margins over his arms and face which raised the suspicion of homicidal sharp weapon trauma. The injuries were seen in clusters and did not involve harder structures such as tendons, ligaments, or bones. There were no signs of inflammation or bleeding. They were attributed to kabaragoya claw marks, which are postmortem artifacts that mimic incised wounds. However, there were no areas of tissue loss to indicate that the animal had begun feeding on the corpse. This case discusses the problems faced by medicolegal investigators when encountering this phenomenon which is relatively underreported in the forensic literature.



How to cite this article:
Dileka P, Gunathilaka CM, Ranchamali T, Gunawardena SA. Differentiating postmortem claw marks by the Asian water monitor (kabaragoya) from antemortem sharp weapon trauma based on the injury pattern.J Forensic Sci Med 2022;8:114-117


How to cite this URL:
Dileka P, Gunathilaka CM, Ranchamali T, Gunawardena SA. Differentiating postmortem claw marks by the Asian water monitor (kabaragoya) from antemortem sharp weapon trauma based on the injury pattern. J Forensic Sci Med [serial online] 2022 [cited 2022 Sep 27 ];8:114-117
Available from: https://www.jfsmonline.com/text.asp?2022/8/3/114/355564


Full Text



 Introduction



Postmortem animal predation is a well-known cause of artifactual injuries in a dead body which may mimic antemortem trauma or alter the appearance of antemortem trauma.[1] Monitor lizards belonging to the reptilian group Varanidae are widely distributed over the world and are well known for scavenging on dead animals.[2] There are mainly two species in Sri Lanka: the Bengal land monitor (Varanus bengalensis) and the Asian water monitor also known as kabaragoya (Varanus salvator).[3] The kabaragoya is the predominant large animal scavenger of human remains in Sri Lanka and is perhaps the most significant in the context of forensic pathology, due to the appearance of highly misleading artifactual injuries.[4],[5] This article discusses the medicolegal investigation of a case where postmortem injuries caused by the kabaragoya raised suspicions of homicide. This is a case report based on a forensic autopsy conducted by the authors themselves. No details that identify the deceased, the family, or the inquest are mentioned. Ethics approval for the publication of this case report was granted by the Ethics Review Board of the Sri Lanka Medical Association under ERC number 22/004 on April 08, 2022.

 Case Report



The dead body of a middle-aged male who was missing for 3 days was found partially submerged along a riverbank in Colombo. His family stated that he was on treatment for dementia and depression for several years and had a few episodes of wandering behavior in the past. They denied any previous suicidal attempts. The body was found more than 5 km away from his residence in an area that was not known to the family. The corpse was in a state of advanced decomposition, with bloating and partial degloving of the hands and feet. The arms and legs had been in a partially flexed, raised position (pugilistic attitude), and there were multiple linear injuries on both arms which the family suspected to be from defense injuries due to sharp weapon trauma [Figure 1]a and [Figure 1]b. Therefore, the case was investigated as a potential homicide. On autopsy, he was clad in a shirt and trousers. Several linear injuries were noted over the scalp, face [[Figure 1]c-red arrows], and the right leg [Figure 1]d. Multiple tear lacerations were seen on the right ear lobe [[Figure 1]c – yellow arrow]. No injuries were detected over the neck or posterior aspect of the body.{Figure 1}

Most of the injuries had regular, cleanly separated margins [Figure 2] and [Figure 3], although in some injuries, the separation was ragged [Figure 4]. None of the injuries showed any identifiable erythema or hemorrhage. All the wounds involving only the skin and subcutaneous fat [Figure 3] and [Figure 4]. There was no separation of underlying muscles, tendons, or ligaments and the periosteum underlying the facial injuries was intact. Many of the injuries were clustered in linear and slightly parallel distributions [Figure 1]c, [Figure 3] and [Figure 4]. No internal injuries to organs nor evidence of a traumatic cause of death could be found. Triple-vessel occlusion of 60%–75% was observed with a moderately narrowed lumen. No areas of fibrosis were noted in the heart, lungs, or any other organs. The brain was liquefied. Histopathology of the skin wounds, heart, and lung tissue was done using H and E staining. All the sections showed predominantly autolytic changes, and interpretation was limited. However, there was no visible dermal hemorrhage around the injury margins; no evidence of increased fibrosis in the heart and no identifiable vegetative material or foreign bodies in the bronchioles or alveolar spaces. Toxicological investigation for alcohol, opioids, benzodiazepines, and common agrochemicals was also negative. Considering the history of dementia, wandering behavior and the absence of any visible fatal trauma, a probable cause of death was given as the effects of submersion in a man with coronary artery atherosclerosis. Further comments were given stating that the injuries were due to postmortem trauma by animal scavenging.{Figure 2}{Figure 3}{Figure 4}

 Discussion



Several apparent incised wounds were noted on a dead body of a middle-aged male whose body was found partially submerged in a river. He was known to have dementia and wandering behavior, and there were concerns from the family about whether the person had sustained sharp weapon trauma before death. The body was putrefied, and other than moderate calcified coronary atherosclerosis, no other definitive pathology could be found on internal examination. None of the injuries revealed evidence of internal trauma, and histopathology too did not reveal any signs of vitality such as dermal hemorrhage or inflammatory cell aggregates around the injury margins.

Given the level of putrefaction, the ability to clearly differentiate between antemortem and postmortem trauma through histopathology is extremely limited in this case. While the presence of hemorrhage or inflammatory cells in the skin margins is generally indicative of a vital reaction, the absence of such signs does not totally exclude antemortem trauma.[6] Leaching of blood from the injured tissue margins, thus masking the signs of hemorrhage are well known to occur in submerged bodies. Similarly, inflammatory cells are rarely seen if a person dies soon after sustaining trauma. Although methods such as enzyme histochemistry, mRNA, and D-dimers have been extensively studied, their reliability is yet to be established,[7] and their availability is anyway limited in low-resource settings such as ours.

Therefore, to understand the causation of these injuries, it is important to also consider their location, distribution, and pattern. Almost all the injuries showed some degree of clustering and were all limited to the dermis. None of the injuries showed separation of the underlying muscles, tendons, or bones or involvement of internal organs as would be expected from antemortem sharp weapon trauma. These features, therefore, are more consistent with claw marks caused during postmortem predation of human corpses by large monitor lizards in Sri Lanka known as the kabaragoya.[8]

Foraging by the kabaragoya is observed in and around urban habitats[8] predominantly on corpses in relation to a water source.[2],[9],[10] The explanation for the apparently incised wounds is that they have strong curved claws [Figure 5] which they used to grip and stabilize the corpse as they rip off the skin and soft tissues by their jaws.[4],[8] This also explains the reason for the clustered injury pattern. Due to the softening of the skin from putrefaction and especially maceration in submerged bodies, the claws separate the tissue easily which gives the injury an apparent incised effect.[4],[8]{Figure 5}

 Conclusion



This case report highlights the challenges faced during medicolegal investigations of corpses with postmortem artifacts caused by the Sri Lankan species of Asian water monitor lizard (Varanus salvator), also known as kabaragoya. Despite the wide distribution of monitor lizards around the world, this phenomenon has only been reported from Sri Lanka, possibly due to a higher preference of the kabaragoya over other subspecies to forage in proximity to human dwellings. Although the phenomenon is thought to be a consequence of postmortem scavenging, the claw marks seen in this case were not associated with large areas of tissue loss to indicate feeding.

Differentiating these claw marks from antemortem incised wounds can be a challenging exercise and needs a careful examination of the location, distribution, and depth of such injuries. More studies in collaboration with zoologists and animal biologists on the behavior and scavenging habits of the kabaragoya and other monitor lizards would expand our understanding of this phenomenon.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Acknowledgment

The authors thank Dr. Ravindra Samaranayake for the photograph in [Figure 5].

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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