1999-01-15 Sience Nextwave: How to become a Forensic Entomologist
Source: Science Nextwave, Jan. 15, 1999
Personal Perspective on Forensic Science: Maggots Tell All (or: How to become a Forensic Entomologist)
FROM MARK BENECKE
During my studies of biology at the University of Cologne in Germany, I realized that humans are less than unimportant life-forms on Earth, and that insects rule in each and every sense of the meaning.
It was there as a university student that I first became interested in invertebrates, animals without a spine. I spent my nights searching for tropical snails and roaches in our Zoological Garden's terrarium building and my days performing genetic fingerprints of microscopic roundworms and rotifers, as well as training theeight-armed octopus to unscrew a glass filled with its favorite food.
One thing that all German professors will tell you is that you should always do what you want to do. The downside of this was that first I had to find out what I wanted to do. The upside, however, was that once I knew, I was able to convince a zoology professor to let me do my M.S. in his roundworm lab by comparing strains that looked alike under the microscope but weren't on a genetic level. To do this I had to set up my first DNA lab. Through e-mail correspondence, congress visits, and talking with other scientists, I managed to set up my lab and subsequently got into the field of DNA typing.
My professional ties to the DNA typing lab at our local University Institute for Forensic Medicine, as well as my strong desire to work in a multidisciplinary field, is ultimately what brought me into forensic DNA work. In Europe, most forensic labs deal with criminal cases as well as paternity cases. So I decided to develop a method for DNA typing of the urine, hair, and saliva of athletes. Sometimes I was able to use samples from athletes who tried (or not) to cheat during the Olympic summer games in Atlanta, but sometimes I had to resort to using samples from my poor lab colleagues.
After spending a lot of time in the lab, I realized that two doors next to our lab led into the autopsy and storage rooms. I started to ask the forensic pathologists if I could observe some autopsies. At the same time, I went to forensic meetings, parties with our local homicide detectives, and checked out the departments of forensic toxicology, histology, and alcohol determination. After a while I learned enough to pass an examination in "Rechtsmedizin" (medico-legal sciences) during my final oral Ph.D. exams in molecular medicine.
In the autopsy room, I observed something that no one else noticed: The older the corpses, the more bugs I found on them. From that time on, our autopsy assistants secretly (at least that's what they thought) applied insecticides to keep me away from messing around with the fast crawling, white blowfly maggots. But it didn't help. I started to mature maggots and eggs in an empty electron microscopy room, but the smell soon irritated others and I was kicked out. Even the nice vanilla wonder trees I had in the lab didn't mask the odor of the rotting meat I used to feed my new-found study subjects, so I moved into a room located near the so-called corpse entry that had a grating instead of windows.
Until this very day, most of my colleagues absolutely don't want to know about, hear, or see the insects I breed. This can be very annoying (even if it sounds funny) because I don't understand anymore why people are so grossed out. But, my colleagues frequently can't understand why anyone would work with the obviously most disgusting subject on Earth: insects recovered from decaying corpses. I thought that after the movie The Lion King, things would get better because the movie very much focused on life being a circle of birth, growth, maturing, flourishing, dying, and reuse of (body) substances for the next generation. Well, it didn't really work out. I guess I am waiting for the next generation.
After I switched to New York City's Chief Medical Examiner's Office to experience a different legal system, I got more into criminalistics, evidence examination, blood spatter analysis, and the like. But for the second time, a German judge and a forensic pathologist asked for consultation in a high profile case. Last spring, they sent a military plane from Bonn to New York with just four passengers: one human messenger and three blowfly maggots recovered from a crime scene. This time, I went full blast, and together with another entomologist, an ant expert working in the German Museum of Natural History, insect evidence helped to get the case straight.
Routine forensic entomology work is not that exciting. It consists mainly of spotting (smelling, that is) the decomposed bodies before anyone in the autopsy room can wash or freeze them. Most times you won't find anything of relevance during routine checks, but this way you get the expertise and feeling for what is going on in the complex microhabitats. Plus, it is essential to get routine down in determining the species of larvae, pupae, adult flies, and beetles -- which is a frustrating, painstaking process.
So, having said all that, what can a forensic entomology examination add to a case? Apart from the determination of time of death (mostly determined by the body length or weight of maggots), there are numerous other ways of using insects as an aid in investigations. For example, one can find toxins and bacteria from a corpse in insects, even if the body is already skeletonized, which means that not enough tissue is left for standard toxicology and bacteriology. Sometimes, you can also tell if a body was brought from a crime scene to another location by checking for insects on the body that don't belong in the ecological community of the place of discovery. It all depends on your expertise, the circumstances of the case, and your imagination: "What exact questions did the police/forensic pathologists ask, and what other useful things may I read out of the insect material?" For some examples of routine forensic entomology work, you may read more articles on my website (see below). That gives you an idea about the vocabulary of forensic entomologists, too.
If you want to join the field, you should have a natural addiction to insects (especially to relatively common flies and beetles) and, of less importance, to criminalistics. Forget money and doing things just for the sake of social status. You must always try to see the big picture, but at the same time focus on tiny details -- so cross mind barriers on a regular basis and don't restrict your thinking. And finally, find out what you really want and expect from life. The rest will be a piece of cake.
Lesetipps
- Was macht eigentlich ein Kriminalbiologe? (GERMAN TEXT)
- Der Tod ist nicht das Ende (GERMAN TEXT)
- Was nutzen mir Chemie und Biologie? (GERMAN TEXT)
- Was ist Forensik? (GERMAN TEXT)
- Was macht eigentlich... ein Kriminalbiologe? (GERMAN TEXT)
- "Reiche Menschen landen nicht unschuldig im Knast" (GERMAN TEXT)