Creepy Crawling Pieces Of Evidence: The Contributions Of Forensic Entomology On A Crime Scene.

KEY TAKEAWAYS

• Forensic entomology is an infamous field used for investigation based primarily on the life cycle of insects that feed on organic matter. 
• The reports of entomology are recognised for investigating both civil and criminal matters. 
• Medico-legal forensic entomology is the sub-branch which provides information extracted from necrophilous insects. Reports during investigations to solve mysteries of the crime scenes. 
• The span of the insect’s life cycle can be the basis for determining the toxin levels of the deceased. It is the only approach left when the corpse is in the advanced stages of decomposition. The sub-branch of entomology to check the level of toxins is called Foresic Entomotoxicology.
• Insect infestation reports can impose liability on the subject party, especially when a dispute arises in dealing with the food industry.
• The technique is not popular in India due to the lack of awareness and insufficient funds received from the government for its research. 

INTRODUCTION 

Bugs are everywhere, even if you can’t see them. These creepy crawlers have been a part of the earth for more than 350 million years, adapting to fast-paced human development. Playing their part in the ecosystem, insects are rigorously studied by entomologists who track their fascinating lifestyles. From Food & Fashion Industry to Pharmaceuticals, they are a popular choice to used for increasing productivity in their respective fields. Interestingly, forensic science has a different approach to their contribution. Bugs, maggots and flies found on the sites are used as detectives providing information that no one can. This is where forensic entomology comes into the picture, solving the mysteries of murder cases. It is among the recent trends used in medical forensic science solving the riddles to fascinating crime stories. Developed countries like the United States and Canada have successfully solved hundreds of cases by using this biotic approach of forensics. Not just the courts but the leading attorneys have also started relying on the entomological labs to fulfil their purposes. 

WHAT IS FORENSIC ENTOMOLOGY

• It is the study of species belonging to the arthropods for conducting investigation. It typically focuses on the progeny of the insects feasting on the decaying organic matter. The population of the insects, the stage of development, oviparity, and larval stages of the insect are a few areas on which the report relies. Entomologists, who are the experts in this field study the behavioural patterns and life expectancy in comparison when they are introduced to external factors and weather conditions. This technique was a part of the historical epoch but was only popular for its application after the 19th century. To form a basic understanding of insect-borne diseases and effectively treat them, the entomologists continued to research and experiment. The field has seen immense growth since World War I. The efficiency of the reports gained its validity in the judiciary and earned evidential value. 

There are some popular subfields to the field which is mainly segregated into three parts:

1.    Urban forensic entomology:

This specification focuses on the tests conducted on the critters feeding on architectural space. The disputes arising out of tenancies or instruments used for accommodations cover the use of forensic entomology in civil cases. 

Termites affecting wood, bed bugs, and roaches loitering around the site can assist with the timeline of infestation as to when the disputed places were affected by them. The source of such infestation of pests can also be figured out to in these cases and appropriate measures can be taken up for its cure. 

2.    Stored product forensic entomology: 

Tests on food products are conducted when they are affected by pests. This includes harvesting, packaging and storing of the food products infested by insects. By studying the behavioural pattern and the reproduction cycle, one can form an estimation as to when the infestation might have taken place. The tests generally cover issues like contamination, pest-control disputes, stored-product pests etc. 

For example, the food packaging supplied by the manufacturer was contaminated by bugs. The time of the food degeneration can be estimated on the life pattern of the pest which was responsible for infecting the product. Based on the result, the liability can be imposed accordingly.

3.    Medico-legal forensic entomology: 

This subfield focuses on necrophagous feeding on the decaying flesh. The stages of rotting are an excellent base for the estimated date and time of death. Not only the flesh but weapons and evidence excavated during the investigation can pave the way to a better direction. There are numerous examples which helped in arresting the perpetrator. Insect evidence found during the analysis can help in the prediction of the actual site of murder in case the body is moved to another place. In the mystery of murder, determining the cause of death can be established by the behavioural pattern of the organism and the life cycle of the species dwelling on the dead body. The place of death can also be detected easily by the reports of this forensic technique. Temperature is also a beneficial indicator 

Forensic toxicology furnishes reports of toxins levels taken by the consumer. In the case of murder, calculating the quantum of intoxicants is difficult especially when the body is completely decayed. In such situations, the diagnosis is procured with the help of insects. This study of procuring toxins from the body of insects is called forensic entomotoxicology. One way to extract the reports is by gas chromatography. The presence of some toxins accelerates the development of the insect leading to early metamorphosis while others may reduce the rate of colonization. The other upcoming field in forensic entomology is Veterinary entomology which is a steady equipment for poaching and hunting crimes aiding the practices of preserving wildlife. 

HISTORICAL BACKGROUND

●    It is a basic analysis that the dead matter attracts insects. There are numerous references made in the literature books, drama and sonnets where it is mentioned that the corpse attracts the insects. 

1.    THE FLIES WHO SERVED JUSTICE. (CHINA-1219)

The application of forensic entomology traces its origin in the Medieval Chinese-based book “ The Washing Away of Wrongs” which was written by a Chinese lawyer Tung’s Su. 

The author encounters the incident of catching the murderer in the paddy field. The investigators could only figure out the use of a sickle as the weapon used multiple times in slashing the corpse. The sickle holders were asked to keep their instruments in one place. One particular sickle attracted hordes of flies feasting on invisible blood tissues which remained on the instrument confirming the perpetrator. 

2.    CORPSE: HOSTING FEST FOR CUTTERS. 

The handbooks were published by French-based doctors Dr. M. Orfila and Dr. C. Lesueur who discovered the presence of specific insects decomposing exhumed cadavers. Their work gave identity to some insects as species in the Animal kingdom due to their commendable contribution of their publication in 1831.  

3.    POST-MORTEM REPORT: INSECT ANALYSIS

This is said to be one of the first cases where forensic entomology was recognised and introduced to the courtrooms.

The time of a child was detected by Bergeret d'Arbois who used insect succession patterns while conducting an autopsy on the decayed remains of a corpse. The timeline was estimated by the life cycle and successive colonization of the flies hosting over the remains of the carcass. Although his analysis of the insect’s lifecycle was inaccurate, The discovery helped in a successful conviction of the murders. His application paved the way for the inclusion of insect autonomy in investigations.

Attempts to form an understanding of the insects were also made in Calcutta (now Kolkata). The regarding the time and duration of the oviparity and the larval stage. The research was conducted by Mackenzie in 1889 which covers the observation of the eggs laid down by insects and their appearance. However, the traces of these records remain limited. This also establishes that Forensic Entomology was introduced in India long before it gained independence. 

WHY INSECTS?

• Forensic entomology covers cases older than 72 hours helping in procuring accurate results. Sometimes, the stage of decay is such that there are no other alternatives to make up for the elapsed times. There are commonly found insects which feed on organic matter. Maggots, ants, flies, cockroaches, snails, bed bugs and even mosquitoes could help excavate some hidden facts and evidence which cannot be derived through basic equipment of investigations.
• How does forensics use insects?

There are four classes in which arthropods are classified based on their feeding patterns. The classes are mentioned below. 

1. Necrophagous species - those insects which feed on the flesh 
2. Predators and parasites feeding on necrophagous 
3. Omniovorus species feed on the corpses and other arthropods. 
4. The insects are like spiders who use the corpse for accommodation to host other arthropods. 

    Forensic investigators prefer the 1st two classes for investigation. 

• The insects belonging to this category are blow flies, flesh flies, Beatles and house flies. The time of colonization by these insects is closely studied elucidating an excellent base to estimate the time of death of the individual. The corpse is prey to flesh flies and blow flies without any delay whereas the houseflies fancy a later arrival when the decaying is on the bloating stage.
• The criteria used by the entomologist to conduct their study is briefly described below. 

1. Temperature plays a vital role in insect anatomy and hence the experts are required to provide information about the method of estimating the method. 
2. Publishing datasets on the reports which were extracted from the development pattern of the insects found on the body.
3. The reports of the colonisation of the insect collected must be after the death.
4. The insect's reports shall be scrutinised if they are found near the dead body. The reports shall be associated with the insects that are directly linked to the corpse. 
5. The oviposition of the insects occurs in the daytime. The insects usually avoid laying eggs at night and hence the PMI reports are to be determined accordingly. 
6. The reports extracted from entomology may be limited if the body was wrapped, buried or concealed from the invasion of insects. 
7. Seasonal conditions play a viral role in the occurrence of insects as well. The species may also vary for the same reason. 

WHAT HAPPENS AFTER DEATH?

• As soon as a human dies, the dead cells are digested by the enzymes through autolysis. When gastric enzymes destroy the soft tissues, various gases including carbon dioxide, methyl, sulphur dioxide and hydrogen. The chemical activity in the body releases volatile molecules attracting insects to the corpse. The volatile molecule released can also affect the behavioural patterns of the organisms. 

Stages of Decomposition 

Decomposition is an indispensable part of the ecosystem. Based on this understanding, an experiment was conducted on a cadaver which was exposed to the hub of the animal kingdom. The study was conducted by K. Tullies and M. L Goff. Knowing its relevance in criminalistics, the stages of decomposition were divided into 5 parts which are hereinafter mentioned.

• Fresh Stage; 

1.    Tenure 

Beginning of the stage- 1 to 2 days after death 

Ending of the stage- As soon as the bloating is observed 

2.    Observation- 

The insects were attracted within 10 minutes of the death due to cellular breakdown releasing an odor which was not obvious to humans. 

• Bloated Stage : 

1.    Tenure

Beginning of the stage- 2nd  day after death 

Ending of the stage- 7th day after death 

2.    Observation-

Inflammation of the body due to cellular breakdown and anaerobic activity. The carcass started to rot attracting flies (Diptera). The carcass started to rot attracting a population of flies (Diptera). The egg and larval stage was discovered along with predators feeding on the larvae of Diptera. 

• Decay Stage:

1.    Tenure 

Beginning of the stage- 5th  day after death 

Ending of the stage- 13th day after death 

2.    Observation-

Penetration of the abdominal wall deflates the bloating stage. The sudden drop in the temperature makes the decaying odour weak. The carcass loses its mass. The stage of the larva is now shifted to the pupal stage. 

• Post decay Stage

1.    Tenure 

Starting of the stage- 10th  day after death 

Ending of the stage- 23rd day after death 

2.    Observation-

Diptera larva leaves the carcass. The carcass is fleshless leaving bones, some hair and tissue and cartilage behind. Byproducts of decay are also present which is seen in larger amounts during this stage. 

• Remains Stage 

1.    Tenure 

Beginning of the stage- 18th  day after death 

Ending of the stage- 90th  day after death 

2.    Observation-

The population of Diptera declines with decaying byproducts dry up. The corpse has little to no cartilage and bones are left behind. 

Based on these stages, the PMI (post-mortem interval) can be calculated which elucidates the tenure elapsed since the time of death. The species of insect has to be identified. After choosing the oldest larva and collecting details of his stage and weight, the age of the larva is ruled out. The temperature has a crucial role to play in it as well. The time of death can also be estimated on the comparative analysis of first-generation insects that were the first ones to be attracted by the corpse. 

CIVIL FORENSIC ENTOMOLOGY

• Forensic entomology is widely used in criminal cases but there are instances where civil feuds which deal with a deficiency in the quality of consumable products. The consumer cases for instance can help the suppliers to establish concrete evidence for deficiency of services. There are situations where the issue is resolved amicably without the interference of judicial authorities. Taking an example from the reports of the entomology lab, the US-based manufacturer saved a profitable deal and also nullified accusations of food contamination imposed by the distributor. The packed raisins supplied were contaminated by the ants attracting complaints from Japanese consumers. The accusation of the infestation of the ants was imposed by the reputed distributor threatening to cancel his contract. The questions which surfaced were where, when and how the ant gets into the packaging. Samples were sent to the labs for analysis. The reports affirmed the presence of ants natives in Southeast Asia. It was then suspected that the packaging was opened somewhere in Japan itself.

The conclusions from the reports of entomology can save from filing a million-dollar suit. The source of the issue attracting the insect can be analysed and rectified further but the areas of research in civil applications are neglected till date. Another concern in civil entomology is that the precautions taken for the specimen in civil disputes are usually lethargic compared to the criminal ones. 

CRIMINAL CASES AND FAMOUS LEGAL CONTROVERSIES

• Where the corpse is in the advanced stages of decomposition, medico-legal criminology is availed to obtain better conclusions. Sometimes, it is the only option remaining with the authorities to take any leads on the case. Considering the insect-based analysis, the temperature, environment and other external factors influence the biorhythm of the insect’s lifecycle. The time of death can also be estimated by tracking the generation progress of the insect. In general, insect evidence can also be relied on in cases wherein the body is displaced from the crime scene. For example, the insects feeding on the corpse may not be native to the place where the body is discovered. 

As discussed above, the insect's evidence can successfully establish the source and the levels of toxins found in the body. Not just the corpse, the insects infecting the wounds of a human can help in forming an estimation of the injury as well. These are helpful in the cases of child abuse and other forms of assault. 

• Understanding PMI reports. 

PMI or the Post Mortem Interval is information about the time since the death of the corpse. The reports of PMI can be accurately derived by using two methods

1. Successional waves of insects
2. By using maggots ages of development. 

The first method focuses on the decaying stage of the carcass in comparison to the geographical and external factors which has its effects on the overall development of insects and its generational growth. Based on the fermentation of carcasses, there are insects like flesh flies which come in minutes after death while the insects like cheese skippers follow a little later. The omnivores and parasites feeding on these insects can also are reliable factors in this method. 

The second method is dedicated to understanding the species and then focusing on the age of the larvae. The dry weight is calculated in comparison to the oldest larvae found in the body. The growth of the larvae is recorded which is correlated with the temperature of the environment in was placed in. After this, the thermal temperature of the crime scene can also be established. 

Here are some cases wherein it was difficult to catch the perpetrator until the insects were given evidential value. 

1.    The murder of the teenage sex worker. 

The body of a teenage sex worker was found on the highway with no prominent leads. The autopsy conducted did not give major leads to the case. The samples of the eggs and larvae of the maggot were collected and various tests were conducted keeping weather and temperature as major elements. The day of the murder was estimated and the charges were confirmed against the army sergeant who confessed to his sins.

2.    The Ruxton case - JIGSAW MURDER CASE

Ruxton was a British Physician who was accused of murdering his wife and maid. Their bodies were strategically scattered after mutilation. The maggots found on the body were treated to estimate the time of death considering the oviparity of insects. The reports collected from the entomologist were later used as corroborative evidence to prove the guilt of the physician. 

3.    Strangled to Death- THE MYSTREOUS DEATH OF MRS. LAUNHARDT

Mrs. Launhardt was abducted and strapped to the closet rod tying her with the strap around her neck. Her husband who was a suspect proved his innocence by presenting entomologist reports in the court of law. He established his wife was alive before 48 hours of abduction. The maggot eggs found on her body helped in estimating the time of death. It was established by the defence that the victim died due to strangling. The evidence was appreciated by the judicial authorities. 

4.    Kuttikunkan Vs. State of Kerala

It was alleged by the defence that the cause of death of the victim was due to different injuries and not due to the injuries caused by the accussed. The injuries on the body were not present before. The life cycle of maggots were used to establish the death timeline leading to the acquittal of the suspect. 

5.    M. Sakthivel v. The State 

In this case, the entomological reports were not relied on in the court of law as the evidence was not carefully handled. The insects were not carefully preserved and taken care of due to which there was a possibility of inaccurate results. Due to such discrepancies, the Hon’ble court rejected the reports received from the labs. 

ACCOUNTABILITY, ETHICS AND CODE OF CONDUCT

• Holding its recognition in legal cases, the research conducted for criminal investigation has to be accurate, reliable and unbiased. The experts involved in the investigation are bound to respect the ethical standards. The evidence obtained from the crime scene shall be handled with precautions as it is holding a piece of sensitive information. The results obtained by analysis shall be conducted carefully and should not be tampered with as they hold evidential value. The false reports present in the court of law can lead to serious consequences of serving injustice. 

INDIA AND FORENSIC ENTOMOLOGY - A much-needed Practice

• India has shown the least interest in progressing their investigation with entomology. Dr. Meenakshi Bharti, who is a research scientist and a pioneer in initiating the study in this field with forensics believes that the crime investigation will boom if there are people who invest in it seriously.  Being at Punjab University, she has even invested her hard-earned to run and maintain the website. Due to the lack of response and no hope of progress, the website now is abandoned. Amongst the few in the research, there is a hope that forensic entomology can cater to the central-based as well as state-based investigating agencies in their workload. 

The lack of experimental corpses is also less for hands-on practicals. People dedicated to the research arrive at conclusions using animal bodies for tests. The labs in India aren’t well equipped for entomological tests neither have experts to conduct such research. With the pendency of multiple cases in the Indian Judiciary, the reports of forensic entomology could provide a bona-find help. Moreover, the expert entomologist would also help agencies for better productivity. The insects found during the drug trafficking raids could be used as informants about the source and supply. This will also reduce the pressure on investigating authorities. Not just limited to the criminal domain, These creepy crawlers can help resolve civil disputes too. Some students are interested in pursuing forensic entomology as a mainstream career but due to the lack of awareness and equipment facilities, they are compelled to pursue their passion abroad because of better career prospects. Hence, to make the most of the studies, the Indian government must promote the experts in the field. The presence of an insect entomologist should be mandated on the crime scene to conduct research. This will help in a better understanding of the case and also ensure a better step to progress. Moreover, the education agencies of India should also concentrate on the forensic curriculum and introduce entomology. This will not just be beneficial for the investigators but also for the Indian lawyers and the legal fraternity.