FORENSIC ANTHROPOLOGY
"Anthropology requires open-mindedness, astonishment, and wonder" (Ruth Benedict)

    Anthropology is a vast field of study, and so is archaeology, both of which can be applied forensic sciences.  Often divided into two areas, anthropology is either: (1) the science that deals with the origins, cultural development, characteristics, social customs and beliefs of humankind (cultural anthropology); and (2) the study of humanity's similarity to and divergence from other animals (physical anthropology). Cultural anthropology has never really had much of a relationship with the law, whereas physical anthropology has always been a recognized area of forensic expertise as least since 1850. It's generally agreed that forensic anthropology is the application of the science of physical anthropology to the identification of skeletal, badly decomposed, or otherwise unidentified human remains. Forensic anthropologists apply standard scientific techniques developed in physical anthropology to identify human remains, and to assist in the detection of crime. Forensic anthropologists frequently work in conjunction with forensic pathologists odontologists, and homicide investigators to identify a decedent, discover evidence of foul play, and/or the postmortem interval. In addition to assisting in locating and recovering suspicious remains, forensic anthropologists work to suggest the age, sex, ancestry, stature, and unique features of a decedent from the skeleton.

    Related specialties include forensic archeology (especially the protocols of excavation), forensic entomology (especially the study of insect larvae), and forensic botany (the use of pertinent plant evidence at a crime scene).  Forensic geology is also an emerging specialty.  Anything undiscovered for 50 years or more is usually arbitrarily defined as "archeological," but there are many who don't agree with this, or recognize things "archeological" in other ways.  The study of insects, or entomology, represents a more unified approach since it deals with fairly established principles from anatomy, morphology, and physiology. Most of the relevant specialties are covered in this lecture, but the initial discussion is on anthropology proper.

    Expert qualifications include possessing an earned Doctoral degree in Anthropology with an emphasis in Physical Anthropology. Applicants must also possess at least three years of full-time professional experience, all or in part devoted to the practice of forensic anthropology. They must document a record of appropriate professional activities in forensic anthropology, and achieve passing grades on comprehensive written and practical examinations which address the broad principles of forensic anthropology. Rarely do forensic anthropologists work for law enforcement agencies or crime labs (with the possible exception of the FAA crash team, where they remain on call). Most are academic professors at schools, centers, and universities. 

    Forensic anthropologists are "bone detectives" who help police solve complex cases involving unidentified human remains. The techniques which physical anthropologists use to discover information about early humans from their skeletons are also used to discover the identity of the victims of accidents, fires, plane crashes, war, or crimes such as murder. A forensic anthropologist can tell a lot about a person from bones:

    Most of these are class characteristics (such as age, sex, race, and height), but some are individual characteristics (such as trauma). Courts would probably never rely independently on forensic anthropological identification. It would most likely be used to corroborate other evidence or supplement the testimony of other experts.  Lawyers frequently stipulate forensic anthropological evidence because much of it may be gruesome and prejudicial to the jury. Bringing bones into the courtroom as demonstrative evidence, for example, is somewhat controversial. Experts are typically allowed to render opinions in wide areas of allied disciplines as long as they are well-schooled in those areas. 

    Police may also turn to anthropologists for facial reconstruction, recreating a face from the skeleton to help them identify the deceased. When asked to create a reconstruction, anthropologists first determine as much as possible from the skeleton, which includes such information as age, race and sex. Then, using tissue thickness sample charts, the artist glues pieces of plastic which look like pencil erasers of various lengths to the skull or a plaster copy, at eighteen to twenty-six key points. These pegs are cut to the thickness specified by the chart. Using the pegs as a guide, the artist fills in the areas with modeling clay. The eyes are the hardest to do as they are almost entirely tissue. Other difficult areas include the ears, because their size is difficult to determine. It is also very difficult to reconstruct the lower parts of the nose and the lips. Computer-assisted facial reconstruction software (FACES) also exists. You can view a demo of the FACES software at http://www.facesinterquest.com/.

ARCHEOLOGY

    Archeology excavation methodology follows a standard procedure that is contained in many protocols, some of which are public and others which are private and proprietary.  One set of public protocols is located at http://archlab.uindy.edu/.  It is important at the outset to determine if you are dealing with partially decomposed tissue or if you are only dealing with skeletal artifacts.  If the former, then you are treading on the area known as bioarcheology, a specialty field with a rich literature base (a sample of which is at   http://www.utep.edu/leb/baref/biblio.htm).  There are few substitutes for laboratory work in this field, and the experience you'll need can only probably be obtained from working a "body farm" that a professor has set up somewhere.  To study decomposition, the typical "body farm" will use a 50-pound pig, the next best thing to a human corpse, and the processes of decomposition are similar.  You would want to bury the pig under various conditions -- wrapped up in something, having been burned first, under different environmental conditions -- that simulate the many conditions under which human corpses might be found.  In a very wet environment (like a rain forest), a body will be stripped to the bone in about 18 days, and in a very arid environment (like a desert), there may still be flesh on the bones after a year.  Some standard procedures to all archeological projects are as follows:

    (1) Clarify the stratigraphy of a site. Soils are normally subdivided into naturally-occurring stratigraphic layers (or strata) that are distinguished by their color, texture, grain size, and material components (silt, clay, and sand). The uppermost layer (topsoil) generally is dark because it contains large amounts of organic material from decomposed vegetation. The deeper layers (subsoil) are generally lighter in color, contain less organic matter, and contain more clay and gravels. The process of digging a hole or clearing a 40' x 40' area disturbs the natural stratigraphy, resulting in a mixing of soil from different strata. The archeologist determines the original layering and reconstructs the sequence of events that disturbed it. Specific disturbances such as burial shafts, animal tunnels, trash pits, campfires, drainage ditches, house foundations, uprooted trees, etc., are called features. The archeologist generally removes a single stratigraphic layer or feature at a time before proceeding to the next deeper one. This will ensure that evidence from different layers or features will not be accidentally mixed. The archeologist may further subdivide a particular layer into levels of arbitrary but standardized thickness (usually 5 or 10 cm).  Remember that the soil composition in the area may have been modified by fluids that have seeped from the body, this being particularly important if you are dealing with skeletal remains.

    (2) Recover all evidence. Small bones and unusual items (such as insect puparia) are easily missed by the untrained eye even when clean, and adhering dirt and debris makes recovery even more difficult. If small evidence is expected, soil and debris is usually screened through 1/4" or finer wire mesh. We commonly employ large rocking screens, hand-held screens, and geological sieves. We use the term evidence loosely to apply to all artifacts and human remains recovered at the scene but also to include miscellaneous items such as footprints, tool-marks, plant roots, insects, graveshaft features, and stratigraphic, locational, or contextual information. Artifacts refers specifically to physical objects that have been used and/or manipulated by humans, including but not limited to jewelry, coins, clothing, weapons, projectiles, and trash. Remains refers to human bones and soft tissues, including teeth, hair, and nails.

    (3) Document the exact provenience of all evidence. Provenience refers to the coordinate location of an item in 3-dimensional space, reflecting its latitude (north-south location), longitude (east-west location), and vertical position (depth), as measured in meters (m) and centimeters (cm). Without this control it may not be possible to be sure exactly how or if an item is truly associated with the remains in question. Archeologists use the metric system to record things because it is much easier to work with than the standard English system of measurement.

    (4) Determine whether evidence is "in situ." An item that is still in the position in which it was originally deposited is said to be in situ. The forces that move items out of position (e.g., humans, animals, water) must be explained and understood.

    (5) Limit postmortem damage to the remains. Uncontrolled removal of the remains with shovels invariably damages fragile bones and evidence. The identification of perimortem trauma is made more secure by controlled archeological excavation using small tools, such as trowels, spoons, and wooden picks

ENTOMOLOGY

    Insects are remarkable creatures. They're the oldest and most dominant life form on Earth, outnumbering animals by three to one. Compared with humans, they might be said to be inside-out because their skeletons are on the outside and their spinal cords are upside-down. They have no lungs, but breathe through tiny holes behind their heads, distributed throughout their bodies in a system of tiny tubes. Most have two sets of eyes, two or three simple eyes, and a pair of compound eyes. Hearing is accomplished with eardrums (for some), or by antennae (for most). Most of them have keen camouflage abilities. They can mimic their environment by changing color, or mimic other insects by changing their behavior. Most of them can be frozen at many degrees below zero, and still be revived. Also, they can handle extreme differences in vacuum or air pressure quite easily. Their most comfortable temperature is the 100-120 degree range. Their social organization, sex control, and egg laying abilities seem to show an intelligence far greater than humans. They seem to be constantly seeking out new, curious, habitats, moving by sense of smell (pheromones), temperature, light, gravity, and air or water currents. They are not affected by tactile stimulation. Their reproductive process is unique. Their eggs hatch into larvae, then enter a pupae stage, and grow into adults from maggots or grubs (metamorphosis). 

    Insects feed on just about anything. A small number are vegetarian (plant feeders), but most are carnivorous. Some are predatory, some are parasites, and others are blood-sucking. Most have an appetite for decaying and decomposing material. Their mouths contain very powerful jaws and needlelike parts that function as teeth. In chewing insects, the mandibles move sideways. Sucking insects have a long proboscis and require liquid food.  Most do not require water, as their bodies either conserve it or metabolize it from food. Their digestive systems are not unlike humans. Insect sex is also not unlike humans.  In a moist, insect-friendly environment, over 300 species of insects will visit a decomposing human body from death through the skeletal stage.  

    Forensic entomologists are mostly called upon to analyze insect larvae in cases where they are feeding and growing inside decomposing human tissue.  Insects enter a corpse through openings in the body -- eyes, ears, nose, mouth, anus, and genitals -- to lay their eggs.  If they enter through another area, chances are this indicates a wound area.  As these eggs hatch and feed, they attract other predators and parasites, such as flies, beetles, and wasps.  Some of these insects have an appetite for human flesh, some preferring a "fresh kill", others the rotting odor.  Flies are the most common insect attracted to the odor of rotting flesh, but they will only be active around such flesh when the outdoor temperature is fifty-two degrees or higher.  By far, the key predator in this regard is the Blow fly (Order Diptera Family Callilphoridae Genus Lucilia Caesar) shown in the top photo.     

    On the lower left is shown a related predator, the Flesh fly (Family Sarcophaga Haemorrhoidalis), and on the lower right is shown the small Screwworm fly (Family Callitroga Hominivorax). 

    All living things are classified into a Phylum - Class - Order - Family - Genus - Species system. Phylum refers to how "high" or "low" the life form is on the evolutionary scale. Class usually distinguishes between structural characteristics (insects, for example, belong to the Class Insecta in the Phylum Arthropods). The Order Diptera is that group of insects where the word "fly" is used as a second word, as in "blue fly" as opposed to dragonfly where "fly" is part of the word. It's often said that Diptera refers to the true "flies".  Orders are further subdivided into families, and families into genera, and genera into species. New "types" or species are always evolving, but a principal rule of zoology is that you cannot have 2 species in the same genus with the same name. For present purposes, we'll concern ourselves with the Order Diptera and certain families of it that prey on humans. 

    Diptera have two sets of wings (front and hind), especially sharp mouth parts, larvae called "maggots", and undergo their metamorphosis either in excrement or animal flesh. They are politely regarded as "nature's scavengers" since, if given time, they will remove all traces of dead carcass from an area. However, where there's large numbers of dead carcasses and Diptera, there's also usually outbreaks of dysentery. Some Diptera are parasitic, which means that, if they can accomplish it, they will try to find a living animal host to plant their eggs in (horses, for example, are especially sought out for this, with the eggs layed on the horse's mouth, which are then swallowed, allowing maggots to grow in the stomach). 

    A Family of Diptera exist (shown in the photos) which are predatory. They seek out, hunt, and prey on animals in hopes of killing them in order to lay their eggs. This is the group we are concerned with, and they love nothing more than to find a human carcass. Blow flies are found practically everywhere, and look like an ordinary house fly, or slightly larger. Many are metallic blue or green. They have especially strong rear legs. Each female lays about 100 or more eggs. A carcass teeming with maggots is usually densely populated by the larvae of blow flies. Flesh flies are also quite common, similar in color, but shaped differently than blow flies (smaller legs, for example). Their larvae tend to be smaller than blow flies, both in size and number. Their preference is to be parasitic, attaching their eggs to a living host, if possible. One species, Wohlfahrtia, only parasitizes humans. Screwworm flies are rather short, fat, and round, existing in numerous species. They prefer to lay their eggs on the skin of a living host. As the eggs hatch, the larvae burrow down under the skin until they find an internal organ. Some parasitic species are so clever as to lay their eggs on a foodstuff right before the animal eats it. 

    By analyzing the rate and pattern of maggot activity in combination with meterological information, forensic entomologists can often estimate or collaborate the time of death (locate the largest maggot, measure it in millimeters and add the number two (2), you'll have the exact number of days since death), as well as give some indication of wound pattern, since the flies involved will often enter through open wounds or bruised areas. However, this expertise is mostly limited to the study of blow flies which operate this way. To give you some idea of the many thousands of species involved, take a look at this Dept. of Agriculture chart:

Order: North
Carolina		 Maine New York Texas World
Diptera 2,111 1,626 3,615 16,700 85,000

INTERNET RESOURCES
Forensic Anthropology MegaSite
ABFA (American Board of Forensic Anthropology)
Cal-State Chico Forensic Anthropology Program
Crime and Clues: Forensic Anthropology
HBO Special on William Bass' Body Farm
Forensic Entomology Website
Forensic Entomology International
Kruglick's Facial Reconstruction Links
Outline of Forensic Archeology
UNC Wilmington's Forensic Anthropology Advising Page
Univ. of Tennessee Forensic Anthropology Center

PRINTED RESOURCES
Bass, W. et. al. (2003). Death's Acre: Inside the Legendary Body Farm. NY: Putnam.
Borror, D. & D. DeLong. (1964). An Introduction to the Study of Insects. NY: Holt.
Brues, A. (1958). "Identification of Skeletal Remains" J. Crim. Law, Criminology & Police Science 48:551-63.
Burns, K. (1999). The Forensic Anthropology Training Manual. NJ: Prentice Hall. [Sample Pages]
Coyle H. (Ed.) (2005). Forensic Botany: Principles and Applications to Criminal Casework. Boca Raton, FL: CRC Press.
Dupras, T., Schultz, J., Wheeler, S. & Williams, L. (2005). Forensic Recovery of Human Remains: Archaeological Approaches. Boca Raton, FL: CRC Press.
Hunter J, Roberts C, & Martin A (1996). Studies in Crime: An Introduction to Forensic Archaeology. NY: Routledge.
Golf, L. (2001). A Fly For the Prosecution: How Insect Evidence Helps Solve Crimes. Cambridge, MA: Harvard Univ. Press.
Matshes, E. & Juurlink, B. (2005). Human Osteology and Skeletal Radiology. Boca Raton, FL: CRC Press.
Moenssens, A., J. Starrs, C. Henderson & F. Inbau. (1995). Scientific Evidence in Civil and Criminal Cases. Westbury, NY: Foundation Press.
Morse, D., Crusoe D., & Smith H. (1976). "Forensic archaeology" Journal of Forensic Sciences 21:323-32
Morse, D., Duncan J., & Stoutamire J. (1983). Handbook of Forensic Archaeology and Anthropology. NY: Rose Printing.
Ubelaker, D. (1989). Human Skeletal Remains. NY: Taraxacum Books.
Wolf, D. (1986). " Forensic anthropology scene investigations" Pp. 3-23 in K. Reichs (ed.)  Forensic Osteology. Springfield: Charles Thomas.

Last updated: Sept. 30, 2006
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