Posted on 07/24/2002 10:44:59 PM PDT by FresnoDA
You mean that it could be cold or hot as long as there is no moisture available?
I can't type and catch it all at the same time so I missed some of it.
As law enforcement realized the value of this information, increasingly more entomologists got involved. M. Lee Goff, professor of entomology at the University of Hawaii at Manoa and author of A Fly for the Prosecution, is a consultant to the Honolulu medical examiner. His book spells out the many contributions that an entomologist can make in a death investigation.
"Most frequently the forensic entomologist is asked to estimate the postmortem interval based on insect activity," Goff points out. "This is actually an estimate of the period of insect activity, not the actual postmortem interval. The two are often quite close, as the insects arrive and begin their activity shortly following death. In some instances, there may be factors that serve to delay the onset of insect activity, and these must be considered."
Other contributions include:
Goff's first experience at a crime scene was in 1984 with the discovery of the body of a female in Hawaii's Hau Tree Park area, located in Ewa Beach. "I had previously participated in a number of cases at the morgue, but this was the first time someone got me out of bed to go to a scene." Since then, he's been increasingly more involved.
In the case of one victim who appeared to have been dead for at least two weeks, the insects had done quite a job. Goff and his assistant collected the specimens and took them back to his lab. They found three species of maggots in different stages of development, which they measured and preserved. They also put some into a rearing chamber to complete their development into adultsthereby differentiating them more definitively. Collecting evidence of one more fly species and two types of beetle, Goff put all of this information into a computer to see if a program that he'd developed would provide a PMI.
The analysis disappointed him: Either no such body existed or there were two different bodies. "In trying to analyze what had gone wrong," he says, "I had to reevaluate the data I had provided to the computer. That led to the discovery of the role that the positioning of the body played in altering the insect activity---particularly the Sarcophagidae larvae." In other words, while it is generally the case that two species would not be on a corpse in the specific stages in which they were found on this one, there was something unique about the crime scene. Goff returned and saw that the victim had been partially submerged, which meant that the flies that might otherwise have left as tissues lost moisture had remained. That was a lesson about the limitations of databases: Any given case may have distinct characteristics that throw the data off.
As time passes, different groups of insects come and go in the process of assisting corpse decomposition. As each feeds on the body, it changes the body for the next group, which is attracted to those particular changes.
Entomologists agree that there are four main types of direct relationships:
"The relationships of the insects to the body, in terms of how they make a living," Goff explains, "are determined by the biology of the insect. Parasites remain parasites, although in some cases the tissue-eaters have been known to switch to predation as the body is consumed. Yet habitat and climatic factors can alter their periods of activity on the body. If the particular insect feeds on dried tissues, it may appear earlier in a hot, arid habitat and possibly not appear at all in a moist habitat. These changes may affect the pattern of succession, but the roles of the individual insects are set by their evolution."
The job of the forensic entomologist is to interpret these various relationships in order to offer information to law enforcement officers that will assist in leads. "At present," says Goff, "entomology is relatively well accepted by crime scene investigators. When I first began, we were regarded as having limited value. Over the years, with educational outreach and careful work, we have become a recognized discipline."
For research---since there's only one Body Farm at this time---he relies on pigs. "I have selected sites for my studies based on the records of localities in which bodies have been encountered. For each study, I use three pigs. One is placed directly on the ground, or on whatever substrate I'm investigating. This pig is left undisturbed for the duration of the study. A second pig is placed onto a welded wire mesh weight platform. This pig is used to determine the rate of biomass removal by weight and will be weighed each time the site is visited. It's also equipped with thermocouple probes inserted into the mouth, abdomen and anus to determine changes in internal temperatures related to decomposition. The third pig is also put on a welded wire mesh platform placed directly on the substrate. This pig serves for sampling of insects and other arthropods. Equipment for recording climatic data is placed at each site, including rain gauge and hygrothermograph."
They then record all factors and add their results into an expanding database.
What Goff finds satisfying about this work is its immediate and practical application. "In many of my academic research projects, I never see any application of the results. Here I see an actual situation and a resolution. I must admit to a certain level of excitement in participating---I'm only human---but I never allow this to interfere with my objectivity."
In 1984, he and several other forensic entomologists began meeting informally, and eventually they decided to form a certifying board. "We modeled ourselves after similar boards in anthropology, odontology and pathology. It was finally incorporated in the State of Nevada in 1996 as the American Board of Forensic Entomology."
In the future, Goff believes that advances in technology will make a significant contribution to the discipline. "For example," he says, "the use of DNA technology to identify immature specimens and extract material from gut contents to allow for individualization of both suspects and victims. Also, we need to focus on standardizing techniques for determining basic life cycles. At present, the data are quite varied, leaving gaps when cases come to trial. Yet even within the relatively new area of drug detection, there have been improvements that allow for more precise analyses. I think it's going to get even more exciting in the relatively near future."
Forensic anthropologists appear to have a considerable range of skills for assisting in death investigations. From art to bugs to bones, they make their mark.
Link
He's not a bugologist...but is an anthropologist...on bugs/incests...early literature says that insects plays a major roles with bodies. He studies insects their pattern of activity, how they mature and interact with that body... various types of bugs will be excluded because of the mummification. larvaes can't penetrate hardened skin
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