In NATURE’s Crime Scene Creatures, we meet a specialized breed of scientists called forensic entomologists who study the insects associated with a human corpse. Though their work may seem less than glamorous to some, they are in fact vital members of criminal investigative teams.

NATURE caught up with Dr. Lee Goff in his office at Chaminade University in Honolulu, Hawaii and asked him to share a little about the fascinating world of forensic entomology.

Please tell us a little about your role in forensic entomology.

Forensic entomology is actually any interaction between the insects and the legal system. This may involve stored product contamination, nuisance problems, structural damage (termites, etc.), and medico-legal. I work within the medico-legal or medico-criminal arena. In these cases, about 98 percent of the work involves providing an estimate of the minimum period of time since death through analyses of insect activity on a body.

Q: What led you to choose the field as a career?

My original training was in marine biology. I shifted to entomology more or less by accident. Due to a misprint in the local newspaper, I applied for the wrong job! I thought I was applying for a technician position in marine biology at the Bishop Museum, but was actually applying for a position in entomology. Since I was putting myself through college at the time, I went for the paying position.

My shift to forensic entomology took place over 25 years ago. I was attending the meetings of the Entomological Society of America in San Diego. I had come to the meetings for an early paper and, when I arrived, discovered the paper had been canceled. Not wanting to walk back to the hotel, I went into the session in the next room, where Dr. Lamar Meek (a pioneer in forensic entomology) was giving a paper on one of his cases. I became interested and started exploring the possibilities in Hawaii. It took a while. The combination of basic science with practical applications was what originally attracted me to the field — plus the fact that I’ve always been a little strange. That combination still remains.

Q: At what point are you usually called onto a case?

In Hawaii, I am typically called to the scene as soon as it is discovered and determined that entomological evidence is involved. I go to the scene and begin my examination and collections there. Typically, I also go to the morgue to make additional collections and observations during the autopsy procedure. If the case is on the mainland, I am often contacted while the scene is being assessed and talk the investigators through the process.

Q: How important is it that you collect your data before a body has been moved?

If the body is moved before collections are made, you can lose significant evidence. The insects will leave the body or move to a different part of the body.

Q: Could you describe the materials and methods you apply to your work in the field?

I have a basic kit that I’ve assembled over the years that is small enough to stay on my motorcycle. This includes all of my basic collecting equipment, a net and containers to transport the specimens. My work in the field consists of examination of the body and the surrounding area for insect evidence. Generally, I begin with the upper exposed surfaces of the body and then, as the body is moved, I look at the lower surfaces and then the substrate. I do not remove or otherwise disturb clothing during these examinations so that other types of evidence will not be disturbed. For the immature species, I split my collections into two lots. One lot is fixed and preserved at the scene in order to stop the biological clock. The other is placed into a rearing container to allow me to rear these specimens to the adult stage in the laboratory for a positive species-level identification. Many times the adults are easy to identify but the larvae are indistinguishable. Collections are made from all different areas of the body and surroundings, and these are all kept separate. I also make collections during the autopsy procedure. In the morgue, I can spend more time going through clothing for species I may have missed in the field. Examinations of the internal tissues and wounds may also yield species of major significance to the final analyses.

Q: Could you describe how you work with other forensic scientists to piece together a case?

I provide only one piece of the puzzle that is the crime. Others work to provide other pieces. We typically work independently, each on their own area of expertise. Generally speaking, I do not solve cases. I only provide analyses of the evidence. I leave the solutions to law enforcement. Forensic workers who decide they will solve the case based only on their piece of evidence frequently become part of the problem and not the solution.

Q: Approximately how many cases have you taken on?

The number of cases per year varies, depending on the homicide rate and what is done with the body. Generally, I work between 10 and 20 cases per year. Hawaii has a very low incidence of violent crime, so my cases are fewer than if I was based on the mainland. To date, I have presented opinions on over 300 cases and consulted on more.

Q: In general, how do you judge the success rate of your work?

A success rate is a matter of opinion. I do not judge by convictions but rather by completion of my analyses. I work to provide an unbiased, objective, scientific analysis of the evidence. When I’ve been able to do this, I have been successful.

Dr. Lee Goff

Q: Where do you see the field heading?

The field is expanding into areas we had not thought possible only a few years ago. Our research is becoming more detailed, and advances in technology are necessitating a reexamination of many previous studies. Advances in computer technology and DNA research are opening areas not previously considered. We still must remember to stay within the limits of our sciences… Secondly, the flies alter foraging behavior. When a female phorid detects a fire ant worker, she’ll stalk her victim, making the worker run and hide to evade attack. As the ants spend more time avoiding the flies and less time foraging, the entire colony is negatively affected.

Q: Do you find that the popularity of forensic TV programs is generating more interest in the field? Do you feel they do a fair job of depicting the work of forensic scientists?

The recent explosion of forensic shows has definitely increased awareness of the general public and, more significantly, students of the various disciplines in the forensic sciences. Here at Chaminade University, I have observed a phenomenal increase in the students majoring in forensic sciences. I began here approximately six years ago with 15 forensic sciences majors in our bachelor of science degree program. I now have 95 declared majors and another 65 who have indicated they will be declaring forensic sciences as their major. Significantly, these are students of very high caliber who may have earlier been looking at medicine or biology.

The high profile of the TV shows has also increased the expectations of juries. They now expect some type of forensic evidence and almost appear disappointed if they don’t get any. Some people regard this as a problem, but I view it as a positive in many respects. When I began, the jury tended to behave as deer caught in headlights when confronted with scientific evidence. Now they are prepared to hear this type of evidence. If the individuals involved in preparing the cases have done their work properly, they should be able to present this information in a palatable form. In like manner, they should be able to explain the absence of such evidence. As for the reality of the shows, we must remember that they are typically one hour in length and designed to be entertainment, not reality. This includes the “reality shows.” I have worked with the CSI Las Vegas show since the first year. With this group, I have found that they are quite concerned with keeping things within the realm of reality. The time frame is off, but the show is only an hour in length, including commercials. When I have made suggestions concerning my own discipline, they have been more than willing to make appropriate changes.

Q: Are there any general misconceptions about the field?

The most common misconception with regard to forensic entomology is the level of precision of our results. We provide estimates of a period of insect activity on the body and not the actual period of time since death. These are often quite similar, but not always. We begin with ranges in hours, then days, months, season, and, finally, “It’s been there a long time.” This is the reality. If an entomologist states that the “death took place at 3:45 p.m. on the 10th of June, 2006,” you might want to consider that you actually have a potential suspect! The entomology cannot give you those types of results. On the other hand, it can be close enough to establish or destroy an alibi.

Q: Does it take a certain kind of person to handle this kind of work?

It does require a certain type of individual to deal with this work. I guess the bottom line is that you do need to be a little weird to go into this field. At least, that’s what I tell my students. I also tell them that being a little weird is actually a good thing. The successful individuals will develop a somewhat strange sense of humor. This is a defense mechanism that works quite well, even though to those outside, it may seem callous. Underneath this, there is still a sense of compassion.

Many people think it is great when watching from a distance, but find that the reality is not for them. We do willingly go to situations and deal with things that most people tend to avoid. You need an ability to detach yourself from what you are working on at the time. If you allow yourself to become involved in what happened to the individual or what their last moments of life were like, very rapidly you lose your objectivity. Once this happens, you consciously or unconsciously begin to become an advocate for the victim. If your work is to be meaningful, you can only advocate for the truth regardless of where it leads.

To a certain extent, I’ve found a way to remain a small child. When we are small, we are encouraged to wonder about things and turning over rocks to see what’s underneath. Then we reach a point where society tells us to “grow up” and stop turning over rocks. By working in science, I’ve found a way to continue turning over rocks and wondering what is underneath. Of course, I really don’t turn over many actual rocks these days. I turn over other things, but the idea is about the same — although I’m a little more detailed in my actions. There is a benefit to society in what I do.

Q: Do you ever have nightmares?

I do have nightmares on occasion, but not dealing with my work. These generally involve my in-laws moving in permanently or my children deciding to come back home. I used to have one in which I became an administrator. My worst is where I sell my Harley and buy a car. Fortunately, these are all quite rare!

Q: What do you enjoy most about your job?

I enjoy the challenge and unpredictability. These go with forensics in general. No two crimes are alike, and you have a constant change in data and approach. No two days are alike. I can become so lost in the complexities of the interactions between insect species and the body and each other that I can almost forget what I am actually working on. I also like the idea that I am, in some small way, making for a somewhat safer world.

They are among the most reliable witnesses to a crime — expert in their testimony and bulletproof in their account. Yet they never utter a single word. They are the animals, plants, and insects that are being recruited by a special breed of forensic scientists to solve the most seemingly impenetrable of crimes.

Within the United States and around the globe, biologists are joining the ranks of criminal investigative teams to interpret evidence offered by those with a “natural ability” to crack a case. How do ants nesting in a human skull help police to zero in on a suspect? Can microscopic pollen grains track the path of a killer and link him to the crime scene? Astonishing real-life cases illustrate the tactics employed by these supersleuthing scientists and their “wild” associates. We learn how maggots not only can clock the time of death but also are used to trace terrorist activities by revealing the explosives used in a bomb attack, and we meet a dog whose ultrasensitive nose effectively sniffs out a case of arson.

For the investigators, reading the clues requires a strong stomach and a keen eye for the intricate workings of the natural world. A visit to The Body Farm, a forensic research facility in Knoxville, Tennessee, details the various factors in the decay of a human body and how to recognize the false evidence that wildlife may leave. In Vancouver, scientists dive in to explore the more complicated process of underwater decomposition. They are learning how the behavior of curious marine creatures such as enormous sun stars and octopi could taint the evidence.

Step behind the yellow tape and become prime witnesses to the myriad of ways in which Crime Scene Creatures are making it increasingly difficult for criminals to get away with murder.

Online content for Crime Scene Creatures originally posted May 2006.

Through the science of forensic entomology, the study of insects associated with a corpse, we learn that cadaverous critters can tell us a great deal about a crime.

As a body decomposes, certain insects and invertebrates colonize it in a sequential and measured rate. Dr. Gail Anderson, a forensic entomologist at Simon Fraser University in Vancouver, Canada, suggests that after three days, insect evidence is often the most accurate and sometimes the only method of estimating the elapsed time since death. Entomological evidence may also help determine how a person has died, or if a body has been moved or disturbed postmortem. The following case illustrates how the life cycle of a fly helped police solve a murder.

Case 1: Insect Informants

Through the science of forensic entomology, the study of insects associated with a corpse, we learn that cadaverous critters can tell us a great deal about a crime.

As a body decomposes, certain insects and invertebrates colonize it in a sequential and measured rate. Dr. Gail Anderson, a forensic entomologist at Simon Fraser University in Vancouver, Canada, suggests that after three days, insect evidence is often the most accurate and sometimes the only method of estimating the elapsed time since death. Entomological evidence may also help determine how a person has died, or if a body has been moved or disturbed postmortem. The following case illustrates how the life cycle of a fly helped police solve a murder.

The Case:

On a mid-November afternoon, police were called to investigate a foul-smelling odor emanating from a single-family home in the southeastern United States. It did not take long for the investigating officers to discover a shallow grave in the dirt basement of the house, which contained the badly decomposed body of a young female.

It was immediately apparent that the victim had died of a single bullet wound to the head inflicted by a small caliber rifle. A scrupulous examination of the corpse and excavation of the soil in and around the grave site by a forensic entomologist working with police revealed the presence of numerous larvae and pupae of two different fly species.

The specimens were collected from the scene and brought back to the laboratory to be reared. Supplemental information, including weather data and soil temperature, was also analyzed in order to determine the principal climatic conditions at the death site. Based on the developmental biology of both species of flies in that environment, the forensic entomologist estimated that the specimens associated with the body the longest were in their fourth stage of development. It was estimated that the victim had died approximately 28 days prior to the date her body was discovered.

This specific information allowed the authorities to target their investigation in and around the estimated time of death. Within a short time, they identified a female suspect who eventually confessed to having killed the victim precisely 28 days prior to the time the body was found. She further admitted to attempting to bury the victim in a shallow grave in the basement of the house after committing the homicide.

Calculating the developmental rate of the flies provided investigators with the only scientifically reliable method of estimating the time of the victim’s death and subsequently led to the arrest and conviction of the killer.

Case 2: A Grain of Truth

Pollen can certainly be irritating to those who suffer from allergies. But when incorporated into forensics, it not only irritates criminals but also can implicate them. Forensic palynology is the science of analyzing pollen and spores to help solve cases. Microscopic pollen grains from plants of a certain area are assembled in ratios to one another that are unique to that area. When compared with pollen samples from a suspect’s clothing, shoes, or vehicle, these “pollen prints” can point criminal investigators to a specific geographical location, prove or destroy alibis, and link a suspect to the scene of a crime.

Dr. Lynne Milne, a professor at the University of Western Australia in Crawley, is a forensic palynologist who used pollen and spores to help the police catch a killer in Queensland, Australia.

The Case:

In 1996, a young mother of two was discovered brutally murdered in a town called Noosa Heads, on the Queensland coast. Her body was dumped in a park among flowering wattle trees, native to Australia. The victim’s car turned up outside a man’s home in the nearby town of Gympie, inland from Noosa. Flower petals and plant debris littered the car’s interior. When police questioned the owner of the house, he outright denied having recently been in Noosa or driving the victim’s car. He did admit that the previous day he had walked on a path in Gympie where wattle trees were common. Though the police had their suspicions about the man, they had no hard evidence to tie him to the crime.

The police turned to Dr. Milne in the hope that she would shed some light on the case with regard to the plant matter. She observed that the wattle trees in Noosa are of a different species than those in Gympie and generally flower at a different time. She analyzed pollen samples from the two species at each location and identified their “pollen print.” She then examined pollen from the flowers that were found in and on the victim’s car, as well as samples vacuumed up from the car’s upholstery and lifted from the suspect’s clothing.

Dr. Milne’s analysis revealed that all of the flowers were indeed from Noosa, not Gympie, and that most of the pollen in the car and on the suspect’s clothing was also from Noosa — and a perfect match. This evidence was used to link the suspect to the scene of the crime. He was arrested and brought to trial, where he was convicted of the murder and sentenced to life imprisonment.

Case 3: Wooden Witnesses

The structure and physical nuances of wood can be as distinctive as a fingerprint and just as useful in solving a crime. Forensic wood anatomists are able to glean important clues on both macro- and microscopic levels — from matching growth patterns in large pieces of lumber to analyzing the physical characteristics of a splinter-sized fragment.

The first and perhaps most famous case in which wood anatomy was used in the court system to help solve a crime was the Lindbergh baby kidnapping.

The Case:

In the early morning hours of March 2, 1932, Charles Jr., the 20-month-old son of aviator Charles A. Lindbergh and heiress Anne Morrow, was snatched from his crib in his second-floor nursery. A broken handmade ladder was left at the scene. Several weeks after the kidnapping, Arthur Koehler, a wood anatomist at the Forest Products Lab in Madison, Wisconsin, was asked by the FBI to identify some splinters from the ladder. Koehler requested that he be allowed to examine the entire ladder, as it might provide him with key information regarding the crime. His request was granted 10 months later.

Upon closely examining the ladder parts, he noted a set of square holes in one rail that did not correspond to the ladder’s construction. He also discovered nicks left by tools including a hand saw, a chisel, and a hand plane, and the distinctive marks of a machine planer with a flawed blade. Koehler set out to find the mill that had manufactured the boards with the unique machine planer marks. After six months of visiting various mills in the area, he finally found a match — but all his hard work seemed to prove fruitless when he discovered that the mill held no records of past customers.

In September 1934, the police arrested Bruno Hauptmann as a suspect in the case when he tried to spend some of the marked ransom money. A search of his home turned up two hand saws that fit exactly the scratch marks left on the ladder, a hand plane that matched the marks on the ladder rungs, and nails identical to those in the ladder. Perhaps the most incriminating piece of evidence was a missing floorboard in Hauptmann’s house. It became obvious that one of the rails of the ladder was fashioned from it. Not only did the nail holes of the remaining floorboards match the misfit holes of the rail but also, Koehler showed through the comparative anatomy of the wood, the growth rings and grain pattern from the rail perfectly matched the wood from the remaining floorboards.

To the end, Hauptmann insisted he was innocent. He proclaimed proudly that he was a carpenter and if he had made the ladder, it certainly wouldn’t have broken. Nonetheless, he was convicted and sentenced to death.

WEB SITES

American Board of Forensic Entomology

http://www.research.missouri.edu/entomology/

Learn more about the science, history, and case studies in the realm of forensic entomology.

Crime Scene Investigator Training

http://www.crime-scene-investigator.net/csi-training.html

Learn how to prepare for and find a job in CSI on this site.

Crime Scene Online

http://www.crimescene.com

Review evidence, interviews, and other documents from fictional cases and discuss them with fellow Web investigators on this interactive site.

Death Online

http://www.deathonline.net/decomposition/index.htm

Browse this site to find out more about the corpse fauna and other natural processes that take over after death.

Dr. Gail Anderson

http://www.sfu.ca/~ganderso/

Learn about Dr. Anderson’s role in the exciting world of forensics.

Dr. M. Lee Goff

http://www.chaminade.edu/csi/index.php?pg=content_leeGoffBio.html

Meet Dr. Goff and learn more about his work in forensic entomology.

Dr. Lynn Milne

http://science.uniserve.edu.au/faces/milne/milne.html

Get to know forensic palynologist Dr. Lynne Milne and how she is helping to solve crime through pollen.

Forensic Anthropology Center

http://web.utk.edu/~anthrop/index.htm

Unearth the details of forensic anthropology through this center founded by Dr. Bill Bass of The Body Farm.

Forensic Entomology

http://www.forensic-entomology.com/

Dive into this comprehensive site to learn more about how a forensic entomologist can aid in a death investigation.

Forensic Pages

http://www.shambles.net/pages/learning/ScienceP/forensic/

Explore more forensic science links on this site.

Forest Products Laboratory

http://www.fpl.fs.fed.us/aboutus.html

Learn more about wood anatomy and its role in forensics through the nation’s leading wood research institute.

International Crime Scene Investigators Association

http://www.icsia.org/

Search this site for great information on becoming a crime scene investigator, as well as useful professional links and job listings.

Visible Proofs

http://www.nlm.nih.gov/visibleproofs/

Explore significant cases, technologies, and people that have had an impact on the history of forensic medicine.

BOOKS

Bass, Bill, and Jon Jefferson. DEATH’S ACRE: INSIDE THE LEGENDARY FORENSIC LAB, THE BODY FARM WHERE THE DEAD DO TELL TALES. New York: Putnam, 2003.

Erzinclioglu, Zakaria. MAGGOTS, MURDER, AND MEN: MEMORIES AND REFLECTIONS OF A FORENSIC ENTOMOLOGIST. New York: St. Martin’s Press, 2000.

Evans, Colin. THE CASEBOOK OF FORENSIC DETECTION: HOW SCIENCE SOLVED 100 OF THE WORLD’S MOST BAFFLING CRIMES. New York: Wiley, 1998.

Genge, N. E. THE FORENSIC CASEBOOK: THE SCIENCE OF CRIME SCENE INVESTIGATION. New York: Ballantine, 2002.

Goff, M. Lee. A FLY FOR THE PROSECUTION: HOW INSECT EVIDENCE HELPS SOLVE CRIMES. Cambridge: Harvard University Press, 2001.

Greenberg, B., and J. C. Kunich. ENTOMOLOGY AND THE LAW: FLIES AS FORENSIC INDICATORS. Cambridge, UK: Cambridge University Press, 2002.

Lyle, Douglas P. FORENSICS FOR DUMMIES. New York: Wiley, 2004.

Manheim, Mary. THE BONE LADY: LIFE AS A FORENSIC ANTHROPOLOGIST. New York: Penguin, 1999.

Milne, Lynne. GRAIN OF TRUTH: HOW POLLEN EVIDENCE BROUGHT A MURDERER TO JUSTICE. New South Wales: New Holland, 2005.

Walker, Maryalice. ENTOMOLOGY AND PALYNOLOGY: EVIDENCE FROM THE NATURAL WORLD. Broomall, PA, Mason Crest, 2005.

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Online content for CRIME SCENE CREATURES originally posted May 2006.