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FEATURE ARTICLE KALPANA ALPANA SINGH AND RE EEMA EMA SO ONKER Forensic entomology does not only help in conviction but has also helped in saving lives. ‘Who saw him die, I, said the fly, with my little eyes, I saw him die’. I N 1999, two bear cubs were found shot, disembowelled, with their gall bladders removed in Manitoba, Canada. Two suspects were caught but there was no evidence against them. Conservation Officers along with a Royal Canadian Mounted Police (R.C.M.P.) examining the scene of crime collected adult blow ﬂies coming to lay eggs and the blow ﬂy eggs themselves from the remains. The maggots hatching from eggs were reared to adulthood. The hatching time, climatic conditions and lab data were used to ascertain the time of death. This time was consistent with the time that the defendants were seen at the scene of crime. The evidence was used in their conviction. Insect evidence has been routinely analysed to arrive at convictions in homicide cases as well as poaching cases. Forensic entomology applies the study of insects and other arthropods to legal cases, especially in a court of law. These applications are wide ranging but the most frequent is determining the post mortem interval (PMI) in suspicious death investigations. Here the insect and its stage found on the corpse are analysed and used for precise estimation when the SCIENCE REPORTER, JULY 2015 Many insects are attracted to a dead and decaying body depending upon its stage of decomposition (Source: http://www.sfu.museum/forensics/eng/pg_media-media_pg/entomologie-entomology/photo/206/) pathological reports have given a broad approximation. soft drinks, ﬂies in ketchup, beetle legs, body parts found in chocolates etc.). Categories of Forensic Entomology • Medico-criminal entomology deals with arthropod involvement in usually violent crimes such as murder, suicide and contraband trafficking. Forensic entomology can be of four major kinds: urban, stored products, medico-legal or more appropriately medico-criminal, and wildlife forensic entomology. • Urban forensic entomology deals with law suits about misuse of pesticides and litigations and civic law actions involving arthropod pests in house or garden. • Stored product forensic entomology generally deals with litigations and civic law suits involving arthropod infestation or contamination of a wide range of commercial products (insects found in 20 • Wildlife forensic entomology helps in settling cases related to wildlife crimes such as poaching and trafficking. History of Forensic Entomology The first documented case of the use of forensic entomology in solving a crime is found in a 13th century medico-legal Chinese textbook by Sung Tzu named ‘Hsi Yuan Chi Lu’ (one possible translation ‘The Washing Away of Wrongs’). It describes a stabbing near a rice field. The investigator tells all workers to lay down FEATURE ARTICLE Not only presence but absence of particular insects is also an important clue Forensic entomology as a science is yet to find its place in legal proceedings in our county. Under Article 138 of the Evidence Act of the Indian Constitution any scientific evidence is allowed before court of justice to prove a case. Thus, a general awareness about this branch of science is required as well as trained forensic entomologists. shows evidence of early and active infestation it means this is an antemortem wound. Colonization pattern of insects on antemortem and postmortem wounds leads to variation in the decomposition process. Defensive wounds also show abnormal colonization of insects. Hence, the amount of insects inside the body can reveal the mode of death. their sickles before him. The flies attracted by invisible traces of blood hover around one sickle only indicating the culprit who had washed the blood from his sickle. The rst case reported to estimate the post-mortem interval (PMI) was by a French physician Bergeret in 1855. The case involved blow fly pupa and larval moths. Though a doctor in a hospital, he observed that the state of the corpse was similar to a few other found in different locations on the basis of entomological evidences. In 1881, a German medical doctor Reinhard reported the rst systematic study of forensic entomology when he involved Brauer an entomologist of Vienna, to identify some phorid flies found on exhumed bodies in Saxonia. He also gave a description of beetles from graves older than 15 years. Around the same time an army veterinarian Jean Pierre Megnin documented his work on insects of forensic importance in two volumes – Faune Des Toumbeaux (Fauna of the Tombs, 1887) and La Faune Des Cadavers (Fauna of the Corpses, 1894). Megnin’s work not only advanced the eld of forensic entomology but also greatly popularized the subject. Applications of Forensic Entomology There have been cases involving entomological evidences that demonstrate evidence may still be found after months or after renovation of a flat in which necrophagous (corpse eating) blow fly larva fell from a corpse, hid and developed after months even after disinfection. In a case where even autopsy could not reveal the cause of death, insects developed on the corpses were found containing certain toxic chemicals. Thus, the cause was found to be death by poison. Some insect species are speci c in terms of locations so they are used to determine the geographical location of the occurrence of a crime despite a different site of disposal of the body. A forensic entomologist can easily distinguish which wounds occurred before or after the victim’s death. In a live person scratches, stab wounds or injury by bullet will bleed. Since insects have very speci c food preferences, fresh blood attracts those necrophagus species that feed on this meal. They feed and lay eggs in these open wounds. Postmortem wounds tend not to bleed so will be dry and clean and much less insects will be attracted to this feeding site. If a wound 21 Sometimes insects’ blood trails, feces, eggs and larvae play an important role in determination of the time of the crime. Not only presence but seldom absence of the particular insects indicates an important clue about the crime scene. Many types of insects are studied in forensic entomology ranging from flies, cockroaches to necrophagous insects. Nechrophagous insects such as blow flies, flesh flies, cof n flies, corpse flies, scavenger flies, certain beetles, mites, moths, ants, bees etc. are particularly relevant to medico-criminal forensic entomology. Stages of Dead Body A dead body, either of a human or an animal, undergoes many changes caused by autolysis of tissues. Postmortem changes may be categorised into at least the following ve stages viz. Early stage (0-2 hours), Late stage (2-4 hours), Putrid tissue changes stage (4-48 hours), Bloated stage (48-96 hours), and skeleton destruction stage (days-months). Many insects are attracted to a dead and decaying body depending upon its stage of decomposition. This is called faunal succession. Faunal succession is affected by a number of factors such as weather, sun exposure, air exposure, moisture level, geography, etc. SCIENCE REPORTER, JULY 2015 FEATURE ARTICLE Many types of insects are studied in forensic entomology ranging from flies, cockroaches to necrophagous insects Techniques in Forensic Entomology During most of the history of forensic entomology taxonomic identification based on morphology has been a muchused technique. Potassium permanganate staining of eggs and mock crime scene creation using dead animal in place of corpse to study species succession are other techniques used. Larval weight, larval length and accumulated degree hour techniques are popularly used to assess PMI. Nowadays with the advent of more sophisticated tools such as SEM (Scanning Electron Microscope) and techniques such as molecular genotyping based on both mitochondrial DNA as well as nuclear DNA and gene expression studies the study of entomological evidences has become faster and more precise. Insect characterisation may also be done on the basis of their allozymes. Cases Cracked In UK, Blowﬂy larvae were discovered on decaying human remains dumped in a small ravine in Dumfriesshire, Scotland, in September 1935. The remains were later recognized as those of the wife and maid of Dr. Buck Ruxton of Lancaster. Dr A.G. Mearns reared the maggots in the laboratory and provided a vital clue as to when the murders took place. It helped prosecutors to find Dr. Ruxton guilty of the murders leading to his execution. SCIENCE REPORTER, JULY 2015 Some insect species are specific in terms of locations so they are used to determine the geographical location of the occurrence of a crime despite a different site of disposal of the body. In Germany in 1948, a body of a dead woman wrapped in a sack was found in a moat of a mill. The body was naked except for a pair of red socks. The question was whether the body was dumped immediately after killing or whether it was stored somewhere else before being dumped there. A caddis ﬂy casing was found on one sock and was sent to Hubert Caspers from the Zoological Institute and Museum of the state of Hamburg. The red fibres of the sock could be clearly seen on the upper and lower region of the case, meaning that the case was already built before entering the sack and since the attachment process takes about several days it was estimated that the body was somewhere else. Later on it was dumped in the moat after at least a weak. Forensic entomology does not only help in conviction but has also helped in saving lives. In Austria once there was a case in which a father was thought to have killed his three-year-old child by making her drink sulphuric acid. The father however stated that he had put the child after it had died of natural causes near the window as it was night. In the morning the child’s head was found to be covered with ants. A medical examiner’s findings at autopsy were consistent with the father’s statement thus saving his life. 22 Future Furore Despite 150 years of usage mostly in Europe and USA forensic entomology is still a young discipline especially in India. It is an important branch of science that helps in estimating not only PMI, but also whereabouts of dead bodies. It also helps in estimating drugs and toxicants ingested by a person when alive and also of possible post-mortem manipulations. It may even help in cases of neglect of people who are alive but in need of care by estimating the presence of certain insects or their stages on wounds and natural orifices. Forensic entomology as a science is yet to find its place in legal proceedings in our county. Under Article 138 of the Evidence Act of the Indian Constitution any scientific evidence is allowed before the court of justice to prove a case. Thus, a general awareness about this branch of science is required as well as trained forensic entomologists. In wildlife cases many conservation officers are also unaware of this field of science. Dr. Kalpana Singh is an Assistant Professor in Department of Zoology, University of Lucknow, Lucknow-226007; Email: [email protected] com. Reema Sonker is a research scholar in the same department.