Forensic Anthropology

This site was designed by Terrie Winson to fulfill the requirements of a Forensic Chemistry course at Kutztown University. Its purpose is to provide other students with an overview of Forensic Anthropology and is not meant to be all-inclusive. Special thanks go to Dr. David Webb and Dr. Tom Betts for their encouragement and support.

December, 2004

Inventory & Profile Sex and Race Age Stature & Weight Estimating TOD

The Forensic Anthropologist

"Why study bones? In summary, the answer is that bones often survive the process of decay and provide the main evidence for the human form after death." ¹

"Forensic anthropology is the application of the science of physical anthropology to the legal process. The identification of skeletal, badly decomposed, or otherwise unidentified human remains is important for both legal and humanitarian reasons. 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." ²

Employment as a Forensic Anthropologist is as varied as there are crimes, people and places. After the attacks on September 11, 2001, Forensic Anthropologists were deployed to a base in Delaware to begin the tedious process of identifying bone fragments and teeth. They may be called upon to identify bones and bone fragments sitting in boxes in universities and museums. Sometimes these bones have been in storage for hundreds of years. More than likely, these will be noted to be Indian bones which will eventually need to be repatriated. An anthropologist may also pursue a career with the National Park Service.

"While there are a few forensic anthropologists who work independently (as part of a medical examiner's office, for the military, etc.) the overwhelming majority of forensic anthropologists work out of universities. This means being a college professor who teaches physical anthropology most of the time, and works on forensic anthropology cases some of the time." ³

When skeletalized remains are discovered, one needs to establish first if the bones are human. If so, the sex, race, age, stature, weight, and any pathology of the newly acquired skeleton must be established in order to make an identification of the remains, determine manner and cause of death and, if homicide, identify the murderer. It is the job of the Forensic Anthropologist to pursue these matters, make a report and possibly testify in court.

Inventory and Profile
The Forensic Anthropologist will make a complete inventory of the bones received. A sample inventory is shown on the Case Report page and is always part of the final report prepared on the case. The inventory used for this website is based on a partial skeleton recently acquired by Kutztown University. For the purpose of this website, I will refer to the skeleton as "Earl."

"Earl"
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As part of the inventory, generalized, non-specific words such as "cranium" are generally not used; rather, the specific bone that is present is described in detail. If three bones of the skull are present and in good condition, each of the bones will be identified and described as having no anomalies or pathology. For example, if the left parietal, the occipital, and the right mastoid process were all that remained of the skull in question, they would be listed independently in the inventory. If the skull is complete, that would be stated.

Author with "Earl"
Kutztown University, PA
12/07/04 Top

Sex and Race
After completing the inventory, determinations must be made regarding sex and race. We can sometimes get into a rut because in order to determine sex, we need to know the race. But in order to determine the race, we need to determine the sex. Direct observation of certain features help in the preliminary determination, however in order to deal with any inherent problems that may come up, a number of measurements are taken of the skull and pelvis. In direct observation, a trained eye and touch can separate male from female using the supraorbital margin, mastoid process and gonial flare parts of the skull. However, most important in direct observation is the pelvis.

	Male	Female
General size	Large	Small
Architecture	Rugged	Smooth
Supraorbital margin	Rounded	Sharp
Mastoid process	Large	Small
Occipital bone	Muscle lines and protuberance marked	Muscle lines not marked
Glabella	Bony	Flat
Gonial Angle	Squared	Wide angle
Palate	Larger, broader, tends to be U-shaped	Small, tends to be a parabola
Occipital condyles	Large	Small

Heavily damaged pelvis
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Differences between the Male and Female pelvis

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Spreading caliper (left) and sliding caliper (right)

Using a spreading caliper, taking a measurement from zy to zy

Using a sliding caliper, taking a measurement of nasal aperture

Formulae are used to separate Male from Female and Black from White from American Indian. All the measurements are plugged into these formulae and compared to standards for the final determination. Top

Age
The best bet in determining the age of a sub-adult skeleton is examination of the teeth and jaw, when present. However, a comparative analysis may be made using the skull sutures and epiphyseal fusion in the young-adult skeleton. Sutures are the zigzag "seams" where the bones of the skull meet. Endocranial sutures (inside the skull) are more reliable as an aging method than is ectocranial suture analysis. Epiphyseal fusion refers to the closing of the "growth plates" at the ends of the long bones and clavicle, and iliac crest fusion. The teeth also become important later in the identification of a specific individual.

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Stature and Weight
Stature is determined using the another type of formula called "Regression Formula for Estimating Maximum Living Stature (with standard errors) from Maximum Long Bone Length" of the Humerus⁵. Optimally, the Forensic Anthropologist will have all 6 upper long bones and all 6 lower long bones. Using the average of both right and left humeri, both right and left ulnae and both right and left radii, along with the average of both right and left tibia, both right and left fibulae and both right and left femurs, including the standard error, one can arrive at a fairly accurate estimation of height. This range is then used to estimate weight. An osteometric board is used for obtaining precise measurements of the long bones. Weight is a function of the stature determination. The end result will be a range of heights and weights based on the average standard error.

       Stature
            3.26 x (humerus) + 62.10 = stature +/-4.43cm
            3.42 x (radius) + 81.56 = stature +/-4.30
            3.26 x (ulna) + 78.29 = stature +/-4.42
               (there will be 2 calculations for stature, based on the upper and lower standard of error)

       Weight
            Wt (in lbs) = 4.4 x (stature in inches) - 143
               (there will be 2 calculations for weight, based on the upper and lower standard of error)

long bones (humerus, radius, ulna and hand) were articulated, so had to be folded back
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Estimating Time of Death
The first question to be asked and probably the most difficult to answer is "how long has it been dead?" Bones do not decay as skin and soft tissue do, but they are subject to weathering and scatter (taphonomy). Animal scattering of bones can destroy the context of the crime scene and gnaw marks destroy actual bone. If a body is buried, insects canot get at it, but micro-organisms can. The acidity of soil will have an effect on bone.

Condition of bone depends on the type of burial or exposure along with temperature. The "Body Farm" at the University of TN at Knoxville is a research facility dedicated to the estimation of time of death. Bodies are in all stages of decay and students and faculty meticulously record animal activity, smells, body temperatures, weather conditions. Early into the decay process, a fair amount of skin and soft tissue remain and smells are at their worst. A partial skeletalized body is one in which the bones are still articulated by cartilage and ligaments.

When a body is left on the surface, insect activity will begin immediately and within 2 weeks the body will be partially skeletalized, completely skeletalized within 8 months. If buried, it will take between 1 and 2 years to become completely skeletalized and in arid areas may become mummified.

Bone rot takes many years, and acidity in the soil speeds it up. Scatter is important to the Forensic Anthropologist in estimating time of death/burial. The number and types of bones available at the scene indicates the amount of time the body has been in that spot, i.e. smaller bones get lost first.

TOD estimates based on environmental factors are from research in Tennessee as follows:
       3 weeks -- articulated bones
       5 weeks -- some scatter, some articulated
       4 months -- disarticulated, within 10' circle
       7 to 8 months -- most bones w/in 10' circle and all w/in 20'
       1 year -- small bones missing, complete disarticulation
       2 to 4 years -- some bones broken, scatterd 40', some large bones missing
       12+ years -- bone rot; partial burial*
       15 to 20 years -- no surface evidence
          * partial burial from leaves, storms, erosion from shallow burial

Fabrics may aid the forensic scientist and/or detective in determining length of time since death. Decay of fabrics is based on what the materials are and how long they've been there. Styles of shoes and clothing also help pinpoint dates. Below is a chart representing the most common types of fabrics and exposure to various elements over time.

Material	Length of Time in Good Condition (in months)
Rayon	1-2 if buried	5 on surface
Paper	1 in alk or fresh water	5 on surface/in acid*
Cotton/Wool	6 in alk or fresh water	10 to 15 on surface/in acid
Human Hair	10 to 15 if buried	wind blows it away on surface
Cotton/Poly	15 on surface	25 to 35 if buried
Other Plastics/Leather	15 to 35 on surface	>48 if buried
*paper is partially acid, so acidic soils do not affect it as quickly as alkaline

from: Table 6.4; Morse et al., eds., Handbook of Forensic Archaeology and Anthropology, Florida State University Foundation, Tallahassee, FL, 1983, p. 143.

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Manner and Cause of Death
Manner of death refers to the 5 possibilities: homicide, suicide, accidental, natural and unknown. Cause of death refers to injury or disease, or combination, that results in death and could take months/years. Determining the cause of death is easier with a fleshed body and very difficult with the flesh and organs gone.

Taking X-rays of the skeletal material is very important. One may note old damage to bone that has healed, indicating that this injury did not directly lead to death. Damage from metal objects leaves fragmented metal or metal shavings and saw tooth shavings will show up bright white on X-ray. Bullets will leave fragments of lead.

Fractures
Type	Characteristics
complete	broken all the way through
incomplete	crack; not all the way
comminuted	piece not with the bone
linear	pressure on skull, stress released by cracking; soft blunt weapon
stellate	star-shaped piece missing; hard blunt weapon
depressed	usually with stellate, piece pressed in; hard blunt object, sometimes sharp weapon
broken hyoid	if not adult, not fused; may indicate strangulation
timing	linear cracks do not cross prior cracks; indicate order of attack

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AnthroClub members Mandy, Jen and Allison

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