The Emerging Interface of Entomotoxicology, and in Modern Crime Scene Investigation

Allison Gaines Sarah Cooper Medico-legal Death Investigator (MDI) Biology Department Southern Regional Medical Examiner’s Office Arcadia University 1175 DeHirsch Ave 450 S. Easton Road Woodbine, NJ 08625 Glenside, PA 19038 [email protected] [email protected]

Abstract: Insects and other arthropods are by far the largest biological group on earth, which is why they are found in such a wide variety of places, including crime scenes. For many years, crawling on dead bodies were considered to be just another disgusting element of decay to be washed away during the autopsy, but now forensic specialists have discovered the true importance of the presence of these insects. This revelation led to the development of forensic entomology, the investigation of insects and other arthropods recovered from corpses and crime scenes. Currently, researchers worldwide are using entomology to aid in their criminal investigations. This article examines the emerging interface of entomotoxicology, forensic entomology and decomposition in modern crime scene investigation.

AUTHOR’S NOTE FROM ALLISON GAINES: My consistent processes of decomposition is essential interest in studying human decomposition and the for determining the most likely sequence of events to biological processes that are associated with death have occurred at a crime scene. Once established, began with the start of this sequence of events forms my work at the Southern the basis of the medico-legal Regional Medical Examiner’s prosecution of the crime. Office in Woodbine, New Jersey. As an intern, I was fully immersed in the field, shadowing autopsy Criminal investigations can technicians and medico- be wide-ranging activities that legal death investigators draw upon the expertise of as they analyzed death many people from seemingly scenes and performed unrelated disciplines. In examinations. I instantly modern crime solving, a became more familiar with team of forensic investigators the anatomy of the human might include police body than ever before, personnel, medical doctors, seeing first-hand how injury meteorologists to assess and disease contributes historical weather conditions, to death. Following the statisticians to compile and internship, I was hired as a death investigator for analyze data, biologists and chemists. Most people are the Medical Examiner’s Office, which meant that I familiar with the duties of police personnel and medical had cases of my own to examine. Of all the cases I examiners in criminal investigations but many are not worked on, I was always most fascinated by those that as well acquainted with an emerging sub-specialty of involved advanced stages of decomposition. I was forensic science known as entomotoxicology or with curious to discover what caused the decomposition the use of insects to help establish the post mortem process because I could see how important a thorough interval. Entomotoxicology deals with the detection understanding of decomposition was to a death of drugs and in insects that feed on decaying investigation. The study of death and decay is often organisms and the impact of a variety of drugs on unpleasant, but understanding the immediate and insect development. Knowledge of the post mortem (Continued on next page) 4 HAPS EDucator Spring 2014 interval may be enhanced by the ability of forensic The drugs most frequently encountered in forensic entomologists to make accurate inferences about the entomotoxicology cases include well-known substances time since death based on the size and developmental of addiction and drugs of abuse such as , stage of insect larval harvested at the crime scene. , , diazepam (valium), phencyclidine This article examines the interface of entomotoxicology, (angel dust), amitryptiline (elavil), and a range of major forensic entomology and decomposition in modern and minor antidepressants. The most common insects crime scene investigation. used in entomotoxicological investigation are true , When a person dies, flies are attracted to the body representatives of the insect order Diptera. (Bourel in a matter of minutes. The types of flies vary from 2001, Campobasso et al. 2001, Campobasso et al. region to region, but as a general rule, the metallic 2004, Goff 2000, Verma 2013). blue and green flies commonly seen wherever garbage Current investigative efforts in entomotoxicology seek has accumulated are the first to arrive. Others are to determine the effect of drugs on the development attracted soon after by the smells associated with of insects, particularly blowflies and fleshflies. These decomposition. As soon as the flies arrive, they studies attempt to minimize the potential errors that deposit their eggs in natural openings in the body can arise during forensic investigations by developing such as around the eyes, nostrils, and mouth. If the techniques that measure drug-related alterations in body happens to be naked, eggs will also be deposited insect larval stages. Results have shown that there around the genitals and anus. If there are any open is a statistically significant increase in the rate of injuries present on a body, such as knife or gunshot development in maggots feeding on tissues containing wounds, additional eggs will be deposited in the a of cocaine. Drug related variations in the exposed soft tissue areas. As maggots hatch, developmental rates of insects could be enough they cluster and feed on the soft tissues, to make a difference of up to several days in often reaching such high numbers that the estimate of time of death. The reason they are referred to as “ masses.” for this discrepancy can be understood As they feed on the corpse, maggots when comparing the effects of cocaine progress through a series of life stages on maggots with its effect on humans. called instars. Larva shed their skin Humans who take moderate doses of as they grow through the first, second, cocaine initially become euphoric and quite and third instar stages. Once maggots talkative. They display increased energy, have reached the third instar and are ready appear more alert, and become hyperactive due to pupate, they leave the body, often in such large to an increase in heart rate. As the drug metabolizes numbers that they leave track marks on the ground as in the body, however, these effects diminish. With they go (Campobasso et al. 2001, Ferllini, 2002). maggots, it is their feeding behavior that changes. One of the newest techniques to emerge in crime As the level of cocaine increases maggots become scene investigation is the detection of toxic substances more active. They feed more rapidly, thus ingesting in entomological specimens harvested at the crime more of the drug. This behavior, in turn, increases the scene. Decedents in suspected drug-related deaths rate of development through the larval stages until are not always discovered in a timely manner and by the third instar stage. Once maggots reach this point the time the remains are found biological substances, in their development, feeding and therefore ingestion such as urine, blood and soft tissue organs, which are of cocaine ceases. The cocaine is metabolized traditionally used for drug analysis, may no longer be and, by the beginning of the pupal stage, the rate of present at the crime scene or suitable for analysis. development returns to normal. This process is not In circumstances like this, living adult insects, insect unique to maggots; drug ingestion also affects the adult larva and even the chitinized remains of insects, such beetles, wasps, and other organisms that feed on the as cast-off larval and puparial skins, may serve as cadaver (DeCarvalho et al. 2012, Campobasso and rich reservoirs of the materials found in the drug- Introna 2001, Goff 2000). laced cadavers upon which they have fed. Insects Illicit drugs are of major concern to forensic recovered from badly decomposed cadavers or entomotoxicologists and death investigators because skeletal remains can be homogenized and processed death due to drug overdose is becoming more and using traditional chemical extraction techniques to more prevalent. Cocaine is of particular interest to reveal the substances they have ingested. The most scientists performing studies in this field. It is one common analytic procedures used for processing of the most widely consumed drugs of abuse in the insects that have been removed from cadavers are world, with the highest rates of use reported in North gas chromatography, gas chromatography-mass and South America. An estimated 50,000 people spectrometry (GC/MS), radioimmunoassay (RAI), thin- die as a direct result of cocaine use in the US each layer chromatography (TLC) and high-performance year. In the year 2006, there were 2.4 million cocaine liquid chromatography-mass spectrometry (HPLC/MS). users in the US alone. Cocaine is one of the most

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5 HAPS EDucator Spring 2014 potent CNS stimulants but its potency depends on the corpse and the colonizers, and other species such the form of intake. When taken orally, the drug is as spiders, which use the corpse as an extension of quickly metabolized, which is why most people choose their environment. Each member of this community has to inhale the drug through the nose or to inject the an important role in the decomposition process and drug intravenously. The lethal dose of cocaine when any imbalance can cause significant variations in the inhaled is a mere 20-30mg whereas, when ingested, patterns of decay (Ferllini 2002, Goff 2000). 1g may not even be fatal. Death by cocaine overdose There are several factors that complicate the or hypersensitivity to the drug can occur very rapidly determination of the PMI using insects, making due to rapid increases in blood pressure that can it difficult to use standard methods of estimation. cause the brain to hemorrhage. Current investigations Depredation, or the significant reduction of the indicate that larvae exposed to cocaine start and necrophagous population by social insects such end the pupariation process much earlier than drug as ants and wasps, is a common cause of altered free larvae. They consume more cadaver tissue and decomposition patterns. When a corpse is left gain body weight faster than drug free larvae. Current near a colony of social insects, they may prey upon data suggests that all species of fly larvae may respond the fly larvae at an extraordinary rate, significantly differently to the consumption of drugs, even species altering maggot feeding rate and therefore the rate of within the same family. Future studies that look at the decomposition as a whole. Changes in temperature variation in the effects of cocaine on the development and geographic location alone can alter the growth of a wide variety of cadaver insects will be extremely rate of the maggots feeding on a decomposing corpse. helpful to forensic investigators (DeCarvalho et al. For instance, flies are unable to lay their eggs at 2012). temperatures below 40 degrees and they do not seek Today, the most common use for entomological out bodies after sundown; both of these circumstances evidence is in the determination of the post mortem can effect the estimation of the PMI. Differences in interval (PMI), or minimum time since death. The time of day, season, humidity, and even whether the PMI is defined as the elapsed time from death until body is located in the sun versus the shade can have discovery. The true usefulness of insects in determining drastic effects on the developmental rate of feeding time since death is often under-rated, but the accurate maggots, which also effects PMI determination (Goff estimation of the PMI is extremely important to medico- 2000, Verma 2013). legal death investigations. Currently, there are two Temperature directly interferes with insect activity and approaches to estimating time since death using insect development. Below a certain temperature threshold, evidence. The use of either method depends on the insects are too cold to fly and therefore do not lay eggs state of the decomposing body when it is found. The or deposit larvae. Development ceases altogether at PMI can be narrowed down by analysis of the stages approximately ten degrees Celsius. Heat, on the other of development of the immature flies that are present hand, speeds up development. Warmer temperatures on the remains and it can be further refined using the increase the number and type of carrion insects found principles of insect succession (Verma 2013, Turchetto in association with the cadavers, and the more insect 2001). activity, the faster the degradation process will be. Insect succession is a phenomenon in which each Increased humidity appears to be correlated with organism or group of organisms that feeds on a body higher levels of fly and maggot activity whereas bodies changes the body itself in some way. The changes that found in arid environments may show very little bodily take place make the body more attractive to another destruction by insects (Campobasso et al. 2001, Goff group of organisms, which changes it for the next 2000, Mann 1990). group and so on until the body has been reduced to a Insects can provide valuable clues as to whether a skeleton. This is a predictable process, with different body was moved from one location to another following groups of organisms occupying the decomposing death. Even though insects are found in virtually remains at different times. For example, during the every habitable part of earth, not all insects are found first week or two of decomposition, blow flies and flesh in every habitat. Some are specific to a given type flies are usually the only uniformly reliable indicators of climate, vegetation, elevation, or time of year. If of the post mortem interval. Maggots of these flies investigators find insects that are typically active during remove the soft tissues of the body causing the corpse the fall on a body that is discovered in the spring they to dry out, attracting species like hide beetles that feed know that this is indicative of a death that took place in on dried skin and cartilage. Forensic entomologists the fall. If an insect that is specific to an urban habitat recognize four ecological categories that can be is found infesting a body discovered in a rural area, identified in a carrion community: necrophagous investigators can be fairly certain that the crime was species that are feeding on carrion, predators and not committed at the scene of discovery, and that the parasites that feed on the insects present, omnivorous body was moved after death. Insects can also provide species such as wasps, ants, and beetles that feed on

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6 HAPS EDucator Spring 2014 valuable information about bodily injuries. If maggots the effects of autolysis are visually apparent. It is are found covering an area of the body that is not a first observed by the appearance of fluid-filled blisters natural opening, this indicates that trauma has been on the skin and is followed by skin slippage, drying of inflicted on that area. Antemortem and perimortem the extremities, and a greenish discoloration around injuries are more attractive to insects than postmortem the abdominal area, which is brought about when injuries because they are accompanied by profuse abdominal fat reacts with the breakdown products of bleeding whereas injuries inflicted after death bleed hemoglobin. The processes that characterize the fresh very little. The timing of apparent injuries can be helpful stage of decomposition can persist for as long as seven in determining cause of death and can shed light on days following death (Amendt 2004, Campobasso and possible homicide or suicide cases (Goff 2000, Ferllini Introna 2001, Clark et al. 1997, Galloway 1989, Vass 2002). 2001). Critical to the process of crime scene analysis is Putrefaction, the destruction of soft tissues of the an understanding of decomposition, the predictable body by the action of microorganisms, begins during sequence of biological and chemical events that is early decomposition. During this process, which initiated by the death of an organism and attracts is arguably the most important process for the insects to the cadaver site. Even though studying destruction of organic matter, tissues are digested to human decomposition is often dirty, unpleasant a fluid consistency and will eventually liquefy to the work, it is critical that the decomposition process be point where the skeleton is exposed. This stage is understood because of the impact it has on forensic usually associated with moderate insect activity and investigations. Studies into human decomposition the production of large amounts of foul-smelling gas can help answer the four most important questions in that results in bloating. Hydrogen sulfide is a major any death investigation: Who is the decedent? How component of the gas that causes bloating. It is a did the decedent die? Where did death take place? small molecule that moves easily through body tissues When did death take place? The process of human and reacts with hemoglobin to form a green pigment decomposition begins approximately four minutes called sulfhemoglobin. This pigment initially shows up after death occurs and takes place in four major in the outlines of superficial blood vessels, but later stages: fresh decomposition, early decomposition, is seen in the gastrointestinal region and in areas of advanced decomposition, and skeletonization. The the body where lividity was most marked. As more first processes that occur in the fresh stage of and more gas is released into the body cavities, the decomposition are algor mortis, livor mortis, and rigor body itself becomes physically enlarged and distorted mortis. Algor mortis is the reduction in cadaver body making identification of the decedent more difficult. temperature that occurs after death. It is characterized Putrefaction can begin as early as two days after by a steady decline until it matches the ambient death and can last as long as thirteen days after death temperature. The rate of decline is approximately two (Amendt 2004, Campobasso et al. 2001, Clark et al. degrees Celsius during the first hour and one degree 1997, Galloway 1989, Vass 2001). Celsius per hour thereafter, dependent on existing Advanced decomposition is a state of active decay. It environmental conditions. The gravitational pooling is characterized by changes indicative of accumulating of blood in the body of a decedent is known as livor moisture, such as sagging of the tissues and extensive mortis. It is marked by a reddish discoloration of the maggot activity, or changes indicative of the extreme skin in certain areas where there is blood settling dryness that leads to mummification. Mummification internally. After a few hours, the color will begin occurs in tissues that have survived the active decay to change from red to purple as oxygen gradually process because they are so dry that they possess little dissociates from the hemoglobin of the red blood or no nutritive value for the organisms attempting to cells. Approximately four to six hours following death, feed upon them. Mummification is most likely to occur lividity is said to be fixed because the fat in the dermis in arctic regions and deserts where environmental solidifies in capillaries. The final immediate sign of conditions are characterized by dryness and low death is rigor mortis, the stiffening of the body that humidity. In these conditions, the skin rapidly becomes occurs when the last myosin-actin cross bridge has desiccated before it has time to slough off completely. been formed and there is no more ATP available to The alternative to mummification is skeletonization, an release it. The last cross bridges will break down end stage of decomposition in which the majority of only as a result of the decomposition process. The the bones are exposed. The most favorable conditions accumulation of lactic acid and the breakdown products for decomposition are high heat coupled with high of glycogen also influence rigor mortis. Overall, these humidity. When these conditions are present, it takes beginning stages of decomposition are governed about four weeks for a body to become skeletonized by autolysis, which is promoted by the chemical (Ferllini 2002, Galloway 1989, Mann 1990, Vass 2001). breakdown of cells and the activity of bacteria and fungi within the body. It normally takes a few days before

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7 HAPS EDucator Spring 2014 The four stages of human decomposition should for a wide variety of organisms, returning carbon not be regarded as clearly identifiable, separate and a variety of high quality nutrients to the soil. In occurrences. Instead, they represent a general ecological terms, a decomposing cadaver is an sequence of overlapping phenomena that combine in island of fertility known as a cadaver decomposition an uninterrupted progression until all of the organic island (CDI). Cadaver decomposition islands in the matter is destroyed. The rate of decomposition is natural world are associated with a huge increase in extremely variable and can be affected by several prokaryotic biomass, increased microbial activity and different factors. Ambient temperature appears to have an influx of nematode species into the immediate area. the greatest effect on the decay rate of the human The overwhelming majority of soft-tissue destruction body. During cold and freezing weather, for example, is due to the presence of feeding insects and their the decay process is greatly reduced, or may even larvae. Insects are major players in nature’s recycling cease completely. The most difficult times of the year effort, and in nature, a corpse is simply organic to determine how long someone has been dead are matter that needs to be recycled. There are over 500 during the months when the temperature fluctuates species of insects that take part in the decomposition between warm and cold frequently. Humidity and air process on a daily basis. In the future, a combination ventilation also play a role in decomposition and can of toxicological and entomological information will be be correlated with different patterns of decomposition. needed in order to make the most effective use of the Bodies found in places with little or no airflow, such information gathered from a death site to enhance the as houses and trailers, often show a slower onset of autopsy results. The combined efforts of experts in early decomposition. Dry environments dehydrate multiple disciplines are required in order to perform the the corpse rapidly impairing bacterial proliferation most accurate death investigation possible. whereas humid environments soak tissues and may slow down cadaver degeneration. Coverings such as clothing, bedding, or other similar items may change Literature Cited: the decomposition rate because they can slow down postmortem body cooling that favors the onset of the putrefaction process (Campobasso et al. 2001, Amendt, Jens, Krettek, Roman, Zehner, Richard.(2004) Galloway 1989, Mann 1990). “Forensic Entomology.” Naturwissenschaften. 91(2): 51-65. Another major factor that affects the rate and pattern Bourel, Benoit, Gilles Tournel, Valery Hedouin, Marc of decomposition is the type of environment the body Deveaux, M. Lee Goff, and Didier Gosset. (2001) is left to decompose in. In a terrestrial environment, “Morphine Extraction in Necrophagous Insect bodies lying on the surface of the ground tend to decay Remains for Determining Ante-mortem Opiate much more rapidly than those that are buried. Remains Intoxication.” Forensic Science International 120(1- left directly in the soil frequently show signs of moist 2): 127-31. decomposition such as fungal growth. The depth of Campobasso, Carlo Pietro, and Francesco Introna. burial plays an integral part in the decay rate. Bodies (2001) “The Forensic Entomologist in the Context of buried deeper in the soil, even by a difference of a few the Forensic Pathologist’s Role.” Forensic Science feet, may take many years to decompose fully whereas International.120(1-2): 132-9. those buried at shallower depths may only take a few Campobasso, Carlo Pietro, Giancarlo Di Vella, and months. The rate of decomposition is so variable that, Francesco Introna. (2001) “Factors Affecting in the same environment, a body left in the sun will Decomposition and Diptera Colonization.” Forensic decompose significantly faster than one that is left in Science International .120(1-2):18-27. the shade. Bodies that are submerged in water have Campobasso, Carlo P. Mirella Gherardi, Marina Callgara, completely different rates of decomposition than those Luca Sironi, Francesco Introna (2004) “Drug buried on land. A corpse immersed in water first sinks analysis in blowfly larvae and in human tissues: a and then re-emerges during the bloating stage when comparative study. Int J Legal Med.118:210-214. there is enough gas released to lift it to the surface. Clark, CM, Michael B Worrell, John E Pless (1997) In water environments, fish and crustaceans can Postmortem changes in soft tissue. In William D. ravage cadaver tissues, which can severely disfigure Haglund (Ed) Forensic taphonomy: the postmortem the body and make it seem as though decomposition fate of human remains (pp. 152-155). NY. CRC is progressing more quickly than it actually is Press, Inc. (Campobasso et al. 2001, Ferllini 2002, Galloway 1989, DeCarvalho, Lucila Maria Lopes, Aricio Xavier Linhares, Mann 1990, Vass 2001). and Fortunato Antonio Badan Palhares (2012) There is growing interest in cadaver decomposition, “The effect of cocaine on the development rate of and the analysis of insect remains that so often immatures and ddults of Chrysomya albiceps and accompanies it, not only as it relates to crime solving Chrysomya putoria (Diptera: Calliphoidae) and but also as it affects the local ecology. In a terrestrial its Importance to postmortem interval estimate.” ecosystem, a decomposing body is a temporary Forensic Science International. 220(1-3): 27-32. microhabitat and a rapidly changing food source (Continued on next page) 8 HAPS EDucator Spring 2014 Fertellini, Roxana. (2002) Silent Witness: How Forensic Anthropology is used to solve the World’s Toughest Crimes (pp. 72-79) Buffalo, New York. Firefly Books Ltd. Galloway, Alison, Ph.D, Walter H. Birkby, Ph.D, Allen M. 2013-2014 Jones, M.D., Thomas E. Henry, M.D., and BRuce O. Parks, M.D. (1989) “Decay Rates of Human Remains HAPS Foundation in an Arid Environment.” Journal of Forensic Sciences. 34(3): 607-16. Fund Drive Goff, Madison Lee. (2000)A Fly for the Prosecution: How insect Evidence helps Solve Crimes.(pp. 133-149). In Spring 2013, the HAPS Board of Directors Cambridge, MA. Harvard University Press. awarded a record number of scholarships, grants, Mann, Robert W., M.A., William M. Bass, PhD, and and awards to deserving HAPS members - now is Lee Meadows, B.A. (1990) “Time Since Death the time to donate so it can happen again in 2014: and Decomposition of the Human Body: Variables and Observations in Case and Experimental Field • Three Robert Anthony Awards Studies.” Journal of Forensic Sciences. 35(1):103-11. Turchetto, Marcherita, Sergio Lafisca, and Gabriella • Two Adjunct Faculty Awards Constantini. (2001) “Postmortem Interval (PMI) • Two Sam Drogo Technology Award, Determined by Study Sarcophagous Biocenoses: funded by ADInstruments Three Cases from the Province of Venice (Italy).” • Eight Graduate Travel Awards Forensic Science International 120(1-2): 28-31. Vass, Arpad A. (2001)”Beyond the Grave--understanding • One Faculty Grant Human Decomposition.” Microbiology Today 01. • Four HAPS- I Scholarships 28:190-92. Verma, Kapil, Paul, Reject. (2013) “Assessment of Post Mortem Interval, (PMI), from Forensic The funding of these scholarships, grants, and Entomotoxicological Studies of Larvae and Flies.” awards is the task of the HAPS Foundation. Entomology, Ornithology, and Herpetology 2(1):1- As the Foundation grows, HAPS will be able to 4. http://dx.doi.org/10.4172/2161-0983.1000104 assist more and more of its members in their Accessed September 2013 scholarly development. This benefits us all, as the recipients share their work with us at our HAPS conferences and in HAPS publications. Photo credit: iStockphoto LP, 2014 Now the time has come to generate the funds to ■ support next year’s HAPS scholars. We began with a leadership fund drive during which the HAPS leadership- officers, Board members, and Steering Committee members, demonstrated their unanimous commitment to the mission of the Foundation with their financial support. They believe in leading by example! Now it’s time for all of us to do what we can to help the Foundation grow and support our members.

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