Skip to comments.Evidence On Insects Likely To Continue: (Westerfield Trial "Creeps" Along At An Ant's Pace!)
Posted on 07/28/2002 8:56:21 PM PDT by FresnoDA
By Alex Roth
UNION-TRIBUNE STAFF WRITER
July 28, 2002
Expect to hear more evidence about insects as the David Westerfield trial enters what could be the final week of testimony before jury deliberations.
On Tuesday, prosecutors are scheduled to call Dr. M. Lee Goff of the University of Hawaii as their final rebuttal witness in a trial that has lasted 23 court days. Goff is a forensic entomologist and the author of "A Fly for the Prosecution: How Insect Evidence Helps Solve Crimes."
Whether Goff will be the final insect expert in the case jurors have already heard from three witnesses with expert opinions about the behavior of insects on human remains is unclear. Westerfield's lawyers have said they will take at least a day to present evidence to rebut the prosecution's rebuttal.
The trial will not be in session tomorrow because the lawyers and judge are scheduled to hash out the legal instructions that will be read to the jury after the close of testimony. The instructions guide jurors on the law to be applied in the case.
Given the time estimates of the lawyers, it seems likely that closing statements won't come until Thursday, or the following Monday at the earliest. So far there haven't been any Friday sessions in which the jury was present to hear testimony. The judge said the jury will deliberate Mondays through Fridays.
As the case winds down, the battle of the insect experts has emerged as perhaps the final arena in the murder trial. Westerfield's lawyers say the insects found on 7-year-old Danielle van Dam's body prove that it couldn't have been dumped until after Westerfield was under 24-hour police surveillance.
Danielle was reported missing from her home Feb. 2, and her body was found by volunteer searchers Feb. 27 in a remote area off Dehesa Road near the Singing Hills Golf Course in El Cajon.
The defense called two entomologists who testified about blowflies on the girl's body. Westerfield's lawyers say the experts' testimony proves that the remains couldn't have been dumped until mid-February. Westerfield was under constant police surveillance beginning Feb. 5.
The prosecution countered with a forensic anthropologist who said the body's extreme mummification might help explain why blowflies weren't able to access the remains immediately.
Westerfield, a self-employed design engineer who lived two doors from the van Dams in Sabre Springs, is accused of kidnapping and killing Danielle. He is also accused of possession of child pornography, which the prosecution claims shows that he had a sexual interest in girls.
Prosecutors said the pornography some of it depicting violent sexual attacks against young girls was found on Westerfield's computers and on computer disks stored on his office bookshelf.
In a trial of numerous shifts in momentum, legal experts say prosecutors scored a significant blow last week by calling Westerfield's son as a witness. Neal Westerfield, now 19, testified that the computer child pornography in the house was his father's, not his.
Earlier in the trial, the defense presented a computer expert who testified that Neal Westerfield might have been the person who downloaded some of the pornography.
"This is a young man who clearly cares about his dad and has a good relationship with him, so he has no reason to say anything bad," said Peter Liss, a Vista criminal defense lawyer. "He was just truthful."
In this respect, the defense's strategy of trying to blame the son for the child pornography in the house appears to have backfired. Criminal defense lawyer Robert Grimes said the jury is likely to view Neal Westerfield as "basically a nice young college kid" who testified honestly.
Westerfield's lawyers chose not to cross-examine his son. They will indicate this week whether they will call any witnesses to try to refute his testimony.
A forensic entomologist specializes in the developmental stages and behavior of different types of insects found on a cadaver at a crime scene. They provide indicators about the time that has passed since the person's death (PMI), although this is not an exact science. They also indicate something about the climate and locale in which the death may have occurred.
William Bass III
A prominent physical anthropologist who developed expertise in entomology is Dr. William K. Bass III, who runs the Anthropological Research Facility at the University of Tennessee at Knoxville. This two-and-a-half-acre field is dedicated to the study of decomposing human remains, and the presence of more than a dozen bodies at any given time exhibits their ongoing projects. The facility---dubbed the Body Farm by the press--- has made important contributions to estimating the PMI in suspicious deaths.
Bass, an expert on skeletal identification, pioneered this unusual research over thirty years ago when he discovered that the field's state of the art was "mostly anecdotal." Moving to Tennessee in 1971, he got involved in cases where corpses were infested with insects. "Half of my first ten cases were maggot-covered bodies," he recalls. "I didn't know much about that, so I looked through the literature on the subject, and there wasn't much there."
He soon acquired a field and the unclaimed cadavers of several homeless men. As they lay exposed, they provided information about what happens to bodies under various conditions. Insects came in and became the subject of intensive study.
"Before our work, no one had ever established a time line," Bass points out. "There are many factors that can affect how a body decomposes, but we found that the major two are climate and insects. When a person dies, the body begins to decay immediately, and the enzymes in the digestive system begin to eat the tissue. You putrefy, and this gives off a smell." That attracts the bugs. Measuring and recording this information gave the facility its raison d'être.
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.
|M. Lee Goff:
"A Fly for the Prosecution"
| May 18, 2000
It may be morbid or disgusting, but its also amazing. Law enforcement officials can often use beetles, flies, spiders and other insects that prey on the dead to help solve homicide cases. Leading forensic entomologist Lee Goff joins Kojo to discuss this ancient art which is gaining prominence today.
Nate Erwin, Nate Erwin, Manager of the O. Orkin Insect Zoo at the Smithsonian National Museum of Natural History
Poor Jeffy, it's a no win situation for him. It's bad enough that 2 months in to the trial he still doesn't have a theory. Then it's complicated by expert witnesses like, um, Rodriguez. How much worse can it get? Earth to Mr. Dusek, earth to Mr. Dusek.
These people have not one moral bone in their bodies...
Brenda - What's my lyin (line) ?
Damon - Jeopardy.
"That scumbag should be in jail ..."
... please, in the form of a question.
"Shouldn't that scumbag be in jail ?".
Maybe the insects carted off the Dog hairs that would be yet another link. /so
Here's a treat... this trial's theme song... Mash Here
Found pic at cyberslueths
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