“The Impact of poisons, Bugs, and Teeth on Criminal Investigations” Jamie Hagwood


            The science of forensics entails a great purpose—to gather all evidence from a crime scene, break it down, and analyze it for the facts of what occurred. If one were to imagine popular television programs such as C.S.I. or BONES, one may be blind to what forensics truly entails. For example, most security cameras are not going to be as precise to capture an exact license plate, and laboratories take longer than a few hours to capture the facts such as DNA matching. Forensic science is a careful process which takes the time and effort of a great many people from many different fields. According to the U.S. Department of Labor’s Occupational Outlook Handbook, “employment of forensic science technicians is projected to grow 27 percent from 2014 to 2024, much faster than the average for all occupations” (“Forensic Science”). Thus, the need for well-trained staff members to fill these fields of forensic science is growing quickly as well. An in-depth look at the fields of toxicology, entomology, and odontology within forensic science proves how essential these fields are in solving crime.

            The field of forensic toxicology focuses on how toxins enter the body, their effect on the body, and how to apply findings to a real-world analysis of the crime scene. Toxicology is well known to be the study of physiological effects of toxic substances which enter the body. However, much of society is unaware that poisons are always around them. Poisons, also known as toxic substances, are any substances which cause sickness or death at a sufficient quantity. For example, water in large, excessive amounts can cause death, whereas smaller amounts of substances greatly known for their effects, such as arsenic or cyanide, can be almost harmless when ingested (Poklis 107). According to Dr. Alphonse Poklis, forensic toxicology “is concerned primarily with the detection and estimation of poisons in tissues and body fluids obtained at autopsy, or, occasionally, in blood, urine, or gastric material obtained from a living person” (107). Once a toxicologist obtains these samples and analyzes them for poisons, one then interprets the results in order to estimate the effect of the poison upon whomever that sample came from. Toxins can explain whether or not someone died from being poisoned or if drugs were the cause of someone’s erratic movements and behavior, which may explain how a crime scene occurred.

            Forensic toxicology is a careful process dependent upon several factors: the sample taken, how to treat the sample, and interpreting the findings. Toxicologists may use a variety of different body fluids or tissues to determine if poisons were at play in a particular investigation; however, stomach fluids, urine, and the liver can be the most influential upon a toxicologist’s findings (Poklis 116). Stomach fluids are influential to an investigation in that if a poison is taken by the mouth and swallowed, there may be residual amounts of the poison still available in the fluids. Urine is also very helpful in that the human body uses the urinary system to deliver all toxins directly out of the body. Similarly, the liver acts as a filter for drugs or other poisons, so a higher concentration of such poisons is expected to be located there. Toxicologists must also understand and identify the biotransformation of toxins, or how the body converts toxins to different chemicals completely (117). They then go on to treat different samples with a multitude of different tests. The quickest and easiest of these lab tests is a color test (119). A color test is where a reagent, or a specific substance used for chemical reactions, is mixed with the sample to cause a color change. Another test that may be used is spectroscopy (124). In spectroscopy, toxicologists use a spectrophotometer to measure how much radiant energy a specific compound absorbs. The specificity of such energy absorption is similar to a finger print, specific to different types of compounds as a finger print is specific to each human. Immunoassay is another technique which may be used by toxicologists (126). In immunoassay testing, scientists use antibodies specific to certain drugs. By observing the binding of the antibodies to specific drugs, toxicologists are able to understand what drug exists in the sample. After toxicologists have analyzed samples, they then must interpret their findings. They may be able to use the findings to determine cause of death or some interpretation of how specific drugs or poisons were administered (127). With insight to such the details of how a human life was taken or the person they were prior to death, a forensic toxicologist proves key in assisting criminal investigations.

            Forensic entomology can serve as an insight to the most specific details of a crime, most often to estimate time of death for victims. Entomology is the study of insects, and insects play a large role in the decomposition of organic material. One may recognize the use of forensic entomology from the show BONES, in which a nationally acclaimed entomologist uses bugs to discover the details of a crime scene. However, this field of forensics is not as simple as its portrayal in popular culture. The combination of location, weather, and the types of bugs around the scene are just a few of the many factors which contribute to an entomologist’s analysis. In their virtual exhibit on forensic entomology, experts from the Simon Frasier University Museum clearly explain, “once a person dies his or her body starts to decompose. The decomposition of a dead body starts with the action of microorganisms such as fungi and bacteria, followed by the action of a series of insects (arthropods)” (“Forensic Entomology”). By applying their knowledge of these waves of insect species and environmental factors, forensic entomologists can evaluate how long a body has been decomposing. This period of time can give investigators a better range of when a murder occurred and have the evidence to catch criminals.

            Forensic entomologists must first begin collecting and processing samples from the crime scene prior to developing a conclusion about a possible time of death or location of a murder. The first step in this process of analysis is taking into account environmental factors such as temperature or soil type (“Forensic Entomology”). Entomologists move on to collect and preserve different specimens. Specimens must be specific to the scene, meaning there is a direct link between the insects and the corpse. This typically includes a newly hatched fly, maggots and eggs inside the body, or beetles under the body. Two methods are used to determine an approximate time of death: insect succession and analyzing maggot age and development. Insect succession looks at the different waves of insect that utilize the decomposing material. Specific species arrive to the scene at specific stages of decomposition. For example, Calliphoridae, or blow flies, may arrive more quickly than Piophilidae, or cheese flies, as cheese flies are attracted to the body at a later stage. On the other hand, an entomologist may observe maggots, or immature flies, develop and become adult flies. The larvae have several stages of molting prior to leaving the corpse and pupating to become an adult fly. Each stage where a blow fly develops is dependent upon a certain amount of time, temperature, and the size of the corpse. Using maggot development, forensic entomologists can determine an estimate of the number of days of decomposition and establish a better range of when death occurred. However, after one generation of blow flies, it is impossible to use this method, as one cannot distinguish between different generations. The methods of insect succession and maggot development may prove tricky, but they are essential in establishing an approximate time of death.

            Forensic odontology, more commonly known as dentistry, applies a knowledge of the human dentition to identify the unrecognizable. The average member of society may only experience dentistry by seeing his or her dentist twice a year. While this general dentist has a great deal of knowledge about the human dentition, they are limited in their ability to match bitemarks or identify specific people by their jaws and teeth. Forensic dentists are able to perform a variety of tests to accomplish those tasks. One of the most important analyses of a forensic dentist is the identification of the dead. In the twenty-first century, society may have very little fingerprint records, and those records can be difficult to sort through (Bernstein 303). Dental records, on the other hand, are much vaster, although they are dispersed between different offices across the country (304). Teeth are extraordinary in that they are the hardest tissue in the human body. Thus, even if many years have gone by and a missing person is recovered, then their teeth can be the key to liberation of anonymity (299). Even when a deceased person does not match a name in the missing persons database, a forensic dentist has the ability to determine other key factors about the person before death. Forensic dentists can determine age through knowledge of how teeth develop (306). For example, a younger child has layers of enamel and dentin which can be examined, similar to the rings in a tree. They may be able to look at wisdom teeth and their positioning for teenagers and young adults. Forensic dentists may also determine the gender of the deceased, although this data may not be the most reliable as differences between the subjects are very subtle (308). Another important act of a forensic dentist is analyzing bitemarks. A bitemark may be an indentation in the skin or bruising of the skin by teeth. People have unique teeth structures, and as such, dentists may be able to identify unique individuals by their unique bitemark (319). This is helpful in cases of assault, where a forensic dentist can quickly match to a suspect.

Both key pieces of evidence – identification of the deceased and bitemark analysis—that a forensic odontologist provides have unique processes to take evidence and analyze it. In dental identification, some of the first steps are preparing to examine the facial structure and proceeding to perform an oral autopsy (Bernstein 310). In an oral autopsy, a dentist typically photographs and x-rays their findings, taking notes as they process the unique characteristics of the deceased. The condition of the remains is key. For example, Dr. Mark L. Bernstein explains, “charred remains are the most difficult to examine” (313). If the body is burned, then the tissue is very damaged. Although teeth are the most durable part of the human body, heat and fire can cause them to become fragile and shrink. After recording the condition of the body and the uniqueness of the dentition, the dental records of a possible match are needed to connect the body to a name. In bitemark analysis, an odontologist must be quick to collect evidence (328). Indentations and bruising fade within hours or even just a day. Photographs are taken and other members of the forensic team may swab for saliva. Forensic dentists themselves may take close-up photographs to record the size and shape of the mark (329). They may go on to take impressions of the bitemark, rendering it three-dimensional. A dentist may also examine a possible suspect—taking photographs and impressions of that individual to discover the truth. Using a bitemark as evidence is tricky, as bitemarks can be distorted and are not always the most reliable (332). Thus, a forensic dentist must be extremely careful when forming a conclusion about their findings. Yet the impact of a dentist’s knowledge about the human dentition in relevance to body identification proves very useful for criminal investigations.  

             Forensic science is in no way similar to how the media dramatizes the forensic process. DNA testing is expensive, and many forms of forensic testing take longer than expected; however, the different fields within forensic science have their own unique processes and applications. Forensic toxicology provides insight to a crime scene’s development and information about victims and witnesses through the analysis of biological fluids or tissues and detecting poisons. Forensic entomology gives very specific details about a deceased person, including the time and location of death. Forensic odontology has the ability to identify the unknown such as names and ages, as well as identifying a possible attacker through indentation in skin and bruising. These fields of study are not perfect; they each have areas for concern and many possible obstacles, but through the efforts of these scientists and the development of science and technology of the twenty-first century, less crime scene data is left to speculation.




















Works Cited

Bernstein, Mark. “Forensic Odontology.” Introduction to Forensic Science, Edited by William G. Eckert, Second, C.R.C.P., 1994, pp. 295–333.

“Forensic Entomology or the Use of Insects in Death Investigations.” Virtual Exhibits, Simon Fraser University Museum of Archaeology and Ethnology; and Teaching and Learning Centre, www.sfu.museum/forensics/eng/pg_media-media_pg/entomologie-entomology/.

“Forensic Science Technicians.” U.S. Bureau of Labor Statistics Occupational Outlook Handbook, U.S. Department of Labor, 17 Dec. 2015, www.bls.gov/ooh/life-physical-and-social-science/forensic-science-technicians.htm#tab-6.

Poklis, Alphonse. “Forensic Toxicology.” Introduction to Forensic Science, Edited by William G. Eckert, Second, C.R.C.P., 1994, pp. 107–131.