Previous articles introduced a case involving the driver of a semi-trailer truck with a route that takes him through five different states. Once or twice a year he picks up a young girl-a prostitute working a rest stop or a runaway hitchhiker-and eventually gets her into the back of his truck. Once there, he chains her up, and over several days repeatedly rapes her and uses small fish hooks to peel the skin from every inch of her body. He keeps the skins as a trophy. When the girls finally die from shock and loss of blood, he picks a secluded wooded area along his route and buries the skinned bodies in the woods. After a heavy rainstorm, a father and son out deer hunting in the deep woods come upon a skeletal hand sticking up from a grave and notify police.
In my last column, I discussed identifying the crime scene’s actual location (it’s not just the burial mound), conducting the preliminary investigation and the special problems posed by outdoor crime scenes. I also touched on forming a recovery team. Every investigation seeks to answer the basic questions of who, what, when, where, why and how, so let’s concentrate on determining who the victim was.
The Investigative Team
The reader has the advantage of knowing the killer’s modus operandi: His victims die from loss of blood and shock. Those conducting the investigation, however, see only a skeleton. Since the body has gone through the various stages of decomposition and is now at the skeletal stage, the investigation requires scientific knowledge and skills beyond that of the police investigator. In fact, forensics is now so specialized that in a case such as this the average medical examiner may not have the expertise to determine cause and time of death.
The skilled investigator recognizes the need to include experts from a variety of scientific fields on the investigative team from the earliest stages possible. Homicide investigation is no longer feet on the pavement, but fingers moving across a computer keyboard to identify and recruit people who have unique scientific skills and are willing to use them. Unlike the popular television crime scene investigation shows, most police departments do not have a crime lab consisting of all of these specialists they can call to the scene. In real life, many experts required by the investigation don’t routinely work for or with the police. Therefore, today’s investigator needs to identify and establish a collegial relationship with a variety of scientists from wide ranging disciplines.
So, in addition to the medical examiner, a recovery team should consist of a forensic anthropologist (for body identification and reconstruction), a forensic odontologist (to work with dental evidence) and a forensic entomologist (who uses insect identification to determine approximate time of death). Since deoxyribonucleic acid (DNA) evidence can be collected on and from a wide variety of sources, the recovery team should include forensic laboratory personnel who can identify probative evidence at and around the crime scene.
Government databases exist that allow crime laboratories across the nation to share evidentiary information, and an FBI database (CODIS) stores DNA profiles of unidentified human remains, but these databases are only as good as the information (evidence) people gather and feed into them. Decisions made the instant police arrive on the scene often determine critical outcomes in this type of investigation.
Forensic Entomology & DNA
In Katherine Steck-Flynn’s 2003 article, “The Role of Entomology in Forensic Investigation,” one excellent section describes the evidentiary value of soil-dwelling insects. ) Flynn points out that only in the skeletal stages do “soil-dwelling insects exist.” At this stage, investigators must take soil samples from under the body and in the immediate area up to 3 feet from the body.1 In addition to other findings, insects in the soil around a body can prove very useful in determining whether the body has decomposed in that location and whether this is a primary or secondary site of death.2 When used in conjunction with other standard methods, investigators can use insect evidence to estimate the post-mortem interval (PMI). This term is more accurate than referring to time of death since the exact time of death is difficult to impossible to predict.3
Investigators don’t need thorough knowledge of how to collect this type of evidence; they need only be well-versed in the science of entomology and how it may aid in the investigation. The field is so specialized it’s part of the investigator’s job to recruit a qualified forensic entomologist who can offer court testimony relative to time and location of death.
DNA, the fundamental building block for an individual’s genetic makeup, is similar to fingerprints in that each person’s DNA is different from every other individual’s except for identical twins. Although environmental conditions can affect DNA (e.g., moisture, bacteria, mold, etc.), you can find it on decades-old evidence.4 And, just a few cells can provide useful DNA information. In our case, the victim’s DNA is viable from bones, the root of a pulled hair, skin cells from clothing, etc. The search of the scene might produce a source of DNA as simple as a toothpick or a used cigarette containing the saliva of the perpetrator.
According to the National Institute of Justice, “Every state in the nation is in the process of implementing a DNA index of individuals convicted of certain crimes, such as rape, murder, and child abuse. Upon conviction and sample analysis, perpetrators’ DNA profiles are entered into a database (the FBI’s Combined DNA Index System, or CODIS). This system can be utilized in a similar manner as when fingerprints found at a crime scene can be run though AFIS in search of a suspect or link to another crime scene."4
In our case, neither the victim’s nor the murderer’s DNA is on file. However, DNA evidence found on scene may eventually link murderer and victim. And if leads develop that indicate who the victim is, investigators can compare her DNA with relatives to confirm her identity. More than 850,000 people were reported missing in 2004, and there’s no way of knowing the number of missing people not reported; it’s always possible the murdered person is not in any government database.
Forensic Odontology
This discipline allows investigators to identify people based on the unique features present in their dental structures. Most dentists don’t have the expertise necessary in dental anatomy, radiographs and pathology to assist in forensic cases. But according to a 2005 article by Dr. L. Thomas Johnson, chairman of the International Association for
Identification subcommittee on forensic deontology, “Teeth and dental restorations are the strongest elements in the human body and survive the destructive influences of fire and exposure to the elements."5 New techniques in digital radiography have greatly enhanced the ability of forensic dentists to make positive identification. Of course, with skeletal remains, investigators must first establish a lead on the victim’s identity and then find any possible dental records for a comparison.
Conclusion
If an investigator has only gender, height, race and approximate age, at least this provides a starting point to query multiple missing-person databases and begin assembling a list of names. The information gathered by the recovery team can also be submitted to the Unidentified Persons index of the CODIS database mentioned above. My next column will describe how to develop an investigative plan to identify the victim, what an autopsy can reveal and how to communicate with and solicit the assistance of other law enforcement agencies in the investigation.
References
1. Baden, M. & Roach, M. Dead Reckoning: The New Science of Catching Killers. Simon & Schuster: New York, NY, 2001.
2. Goff, M.L. A Fly for the Prosecution. Harvard University Press: Cambridge, MA, 2000.
3. Erzinclioglu, Z.Y. Maggots, Murder and Men. St. Martins Press: New York, NY, 2000.
4. National Institute of Justice. What Every Officer Should Know About DNA Evidence. 2005.
5. Johnson, L. Forensic Odontology. International Association for Identification: www.theiai.org/disciplines/odontology. 2005.
