Forensic entomologist
 | It has been suggested that this article be merged into forensic entomology. (Discuss) Proposed since March 2008. |
Forensic entomologists study the science of forensic entomology. Forensic entomologists work in the fields of medicocriminal entomology, urban entomology, and stored product entomology. They are utilized to determine Post Mordem Interval (PMI), or the amount of time since the passing of an individual in the event of unforeseen death. They encounter a wide variety of changing settings and situations that can include the classroom, lab, and actual fieldwork at the scene of a crime.
The Forensic Entomologist
Data Collection
Forensic entomologists are required to take copious amounts of data at the scene. An intense amount of time and energy go into to data collection because everything they collect and observe has to hold up in the court of law. The first portions of information gathered include the climate of the area, both during the time of initial contact to within three to five days afterward. One to two weeks afterward may be required to estimate a rough PMI. Climate approximation is imperative for determining the specific life cycle of insects found at the scene. Good or harsh conditions will either speed up or slow down insect development which gives important information regarding how long the victim may have been decaying (Brundage). In addition to climate, ambient air, soil (around and below the body), and maggot mass temperatures are needed since they are all essential to determining the speed of growth of the insects collected during the investigation. All documentation must be concise to avoid confusion. A death scene form is one of the most important tools a forensic entomologist has. He or she can make note of many key observations quickly such as placement of the maggot mass on the body, temperatures, and stage of decay (Catts and Haskell)[1]. The evidence must be able to pass through the “chain of evidence” (the process of using evidence legally in the judicial system) without fear of contamination, tampering, or any other outside variable that could affect it’s legitimacy during trial in a court of law.
Tools
Forensic entomologists use a variety of tools to determine post-mortem interval:
- Net
- Vials/Kill Jars
- Preservation Chemicals
- Latex Gloves
- Forceps
- Live Specimen Containers
- Shovel
- Thermometers
- Labels
Insect Collection
Collection of adult insects in the area, including flies and beetles, follows as they may become disturbed enough to leave due to the high amount of law enforcement personnel in the vicinity. The most common method is sweep netting, although sticky traps placed near the corpse are utilized as well. Collection of insect adults provides a basis as to what species may be on the corpse in larval form. Collection of larvae is the next step as it is the main route of PMI determinance. Flies prefer to deposit their eggs in any available orifice on the body such as the eyes, ears, nose, anus and mouth. They will also utilize any open wounds to give the developing offspring easier access to necrotized(dead) flesh to feed upon. Different species of larvae have different migration patterns. This refers to the stage of life where they are preparing to pupate, so they migrate away from their original food source to a safer region less vulnerable to prey. It is up to the forensic entomologist on scene to not only collect from around the body itself, but also directly under it. Some larvae burrow up to 3 feet in the ground as well so some digging is required. If the corpse is in an advanced state of decomposition, samples of the morgue chamber climate and insects present from the body bag and during autopsy must be taken as well. Overall, two types of collections are taken: one for immediate observation (preserved using boiling water and “kill jars” or ethyl acetate) and one for insect rearing for larval or pupal identification. Both methods help provide a positive identification for the insect genus and species. One of the most important facets of the forensic entomologist’s job is documentation.
Education
The education needed to become a forensic entomologist is extremely thorough due to the expertise needed to actually practice the discipline. At the undergraduate level, most prospective students major in Entomology. This is the most traveled route into the field of forensics. However, other avenues do exist. Another frequently encountered major is Forensic Science. Students majoring in this would still need to have other entomological education. This ensures that basic concepts of the entomological field are instilled in future entomologists (Hapes). There are also several classes of utmost importance to the aspiring forensic entomologists as discussed by accredited entomologists. These include, but are not limited to: Biology, Chemistry, Genetics, Taxonomy, Medical Entomology, Biochemistry, Forensic Law, Parasitology, and general entomology. It is believed that students with a thorough knowledge of these courses have prepared themselves well for higher study (Kim, Tomberlin, and Merritt). Just as in preparation for other graduate school programs, experience can help boost your resume. Shadowing, or working with professionals who know the field can be rewarding and help prospective students gain valuable insight as to knowing if this field is for them. Summer internships and performing research or lab work in entomology are two ways entomologists suggest that undergraduates can become more prepared for their future work (Kim and Merritt). The main focus for undergraduates needs to be on courses, grades, and experience. A forensic entomologist gains rapport by constantly staying abreast of new ideas that come their way and spending large amounts of time working in the field or conducting research. There are about sixty-two total scientists involved in the field of forensic entomology. Fifty-three percent are solely involved in the “medico legal” branch, the branch that involves insects and violent crimes. Eight percent say that this branch of entomology is one of their specialties. Of the total, most are also affiliated with colleges such as Texas A&M University and Michigan State University where they teach entomology courses and conduct research (Professional Status of Entomologists). Getting to this point as a newly graduated college student can seem a daunting task. It is absolutely essential that one get a degree beyond a bachelor of science (BS). However, currently there are no graduate programs designed specifically for forensic entomology generally. Senior Academic Advisor for the Department of Entomology at Texas A&M University, Rebecca Hapes, made it very clear that individual graduate students in entomology can focus their research on some aspect of forensic entomology, but there is no exclusive program. Most of the entomologists considered to be professional hold a PhD, MS, or MD in entomology or related fields (Professional Status of Forensic Entomologists). It is also important to note that there is no certification test to test the merit of aspiring forensic entomologists. Dr. Jeff Tomberlin, a professor at Texas A&M University with a PhD in Entomology says that the “sole exam available to date is through the American Board of Forensic Entomology” which is further restricted to only those with at least a MS degree. One of the major reasons for this may be attributed to the fact that few entomologists worldwide are employed as full-time medico legal experts (Professional Status of Forensic Entomologists). Most, as mentioned earlier, lend their knowledge and expertise to universities, police agencies, and the legal system when they can (What Is A Forensic Entomologist). It is important to realize that a forensic entomologist can gain rapport by constantly staying abreast of new ideas that emerge in the field and spending large amounts of time working and conducting research to broaden our scope of how insects can affect our life.
Forensic Entomologists of Today
There are several different occupations for forensic entomologists since the field itself is still so very young. Many state universities employ a number of entomologists to teach. Dr. Jeff Tomberlin (former president of the North American Forensic Entomology Association)is an assistant professor for Texas A&M University's entomology department. His responsibilities as an instructor include teaching, maintaining a research program, advising, and working with students who have an interest in working in the field of forensics. Dr. Tomberlin says that, in his spare time, he works with law enforcement agencies and conducts workshops to teach detectives, crime scene investigators, and others on the use of insects in crime scene investigation (CSI). He serves as a consultant in forensic investigations and can even be called upon at times to investigate the presence of insect evidence at crime scenes to determine PMI as discussed earlier. Jeff is most proud of his work with Dr. John Wallace (of Millersville University) in initiating the first conference on entomology to be held in North America. First held in Las Vegas, Nevada, about 50 people registered for the conference which is now in its 6th year and has paved the way for the development of the North American Forensic Entomology Association. The conference has since gone from an annual meeting to the formation of an official society for those interested in the field of forensics. He had the luxury to serve as its first president and was later succeeded by Dr. Wallace.
Although he’s been working in the field for a number of years and has experienced the surge of new developments and advances within forensic entomology, Dr. Tomberlin believes that there is still a great deal more progress to be made in the near future. The urban and stored product entomology arenas are the areas, in his opinion, with the most potential for growth since they both impact the majority of the country in a way much closer to home. He also hopes for more recognition of these two areas and their contribution to the field of entomology. The wide variety of experiences and opportunities for employment help to make forensic entomology among the most diverse careers to have developed among the scientific professions and it looks as though at this rate it will continue to be for a number of years.
Famous Entomological Cases
A more recent and widely publicized homicide case that employed the use of forensic entomology was the David Westerfield trial. Westerfield was convicted and sentenced to death for the kidnapping and murder of seven-year-old Danielle Van Dam in 2002. Van Dam went missing from her home on the night of February 1, 2002, when her parents thought she was asleep in her bed. After weeks of search efforts, on February 27, 2002, the naked, decomposing body of the seven-year-old was found on the side of a road. Defendant David Westerfield, who was a neighbor to the Van Dam family in Sabre Springs, California, became a suspect when he was reportedly not at home the morning Danielle went missing. Westerfield had also been spotted at a local dry cleaners dropping off two comforters, two pillowcases, and a jacket. These articles were later examined and tested positive for the blood of the victim. Once Westerfield was placed under surveillance, the police recovered fiber, hair, and fingerprints that were similar to those of Danielle in the vehicle and the RV of the suspect. Child pornography was also found on his computer. On June 4, 2002, the murder trial began; Westerfield pleaded not guilty. The defense suggested that due to their lifestyle, her parents had put Danielle in danger by being around seedy and untrustworthy people who could have kidnapped her. The defense lawyers also alleged that the child pornography was downloaded by the son of the accused and pointed out the lack of investigation into searching for other suspects. The prosecution called into evidence the fiber, hair, fingerprint, and blood analysis to support their case. Expert witnesses were able to link fibers found on the body of the victim to the home of the accused. Entomology, however, played the star role in the murder trial. The defense had consulted three separate entomologists to call into question the post mortem interval of Danielle Van Dam. The prosecution and defense each hired their own forensic entomology expert witnesses. David Faulkner had originally collected the insects from the remains of Danielle at her autopsy and examined maggots, stating that the insects began growing ten to twelve days prior to finding the body. This discovery did not match up with the prosecution since Westerfield was under surveillance during this time and could not have dumped the body. Faulkner was heavily interrogated as to his method for figuring the post mortem interval and important weather factors. Dr. Neal Haskell also testified for the defense stating that colonization could have occurred February 12th through February 21st . Robert Hall believed the body of the victim could have been infested between February 12th and February 23rd. The prosecution called in Dr. Madison Lee Goff who estimated the last insect infestation occurred February 9th to February 14th. Goff also stressed that other factors may have delayed bug arrival such as the possible use of a shroud, but none was found at the scene. In the end, the jury found Westerfield guilty of kidnapping and first degree murder. These two cases illustrate the importance of the education, training, and job expertise needed to gain the necessary skills needed in forensic entomology.
Conclusion
The wide variety of experiences and opportunities for the future of the practice help to make forensic entomology one of the most diverse careers to have developed among the scientific professions. With continued effort to push information about education and training of forensic entomologists, it is probable that we will see an increase in the use of the field in the coming years. Forensic entomologists today are extremely passionate about their work which can become extremely infectious, if you will, to undergraduate students eager to learn of the opportunities available for their careers.
References
- ^ Catts, E. Paul and Neal Haskell. “Entomology and Death – A Procedural Guide”. South Carolina: Joyce’s Print Shop, Inc, 2005.
Sources
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Catts, E. Paul and Neal Haskell. “Entomology and Death – A Procedural Guide”. South Carolina: Joyce’s Print Shop, Inc, 2005.
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