CE U P D A T E —
F O R E N S I C S II
John K. Lundy, PhD, DABFA
Forensic Anthropology:
What Bones Can Tell Us
The discovery of skeletal remains prompts immediate questions: Are they human? If so, was the
person male or female? What population was he
or she from? How old was the person at death?
How tall was the person? How long has the person been dead? What was the most probable
cause of death?
Forensic pathologists, coroners, and police
officers usually are not properly trained to
recover and analyze skeletal remains. The forensic
anthropologist is best suited to recover and examine these remains and provide answers to these
questions.
Recovery
Because forensic anthropologists are familiar
with the human skeleton, their assistance is
invaluable in the recovery of skeletal remains. The
most common situation where skeletal remains
are found is the surface scatter, which occurs
when a body is dumped on the ground and the
remains are scattered by animals over a wide area.
The forensic anthropologist can determine at the
scene which remains are nonhuman and which
are human, saving investigators' time. If the
remains are buried, archaeological methods are
used to ensure that the amount and quality of
remains recovered are of the highest standard
(Fig l). 1 ' 2
Analysis
After the remains have been recovered in the
field, they usually are transported to a medical
examiner's office or other laboratory facility for
examination.3,4 The remains are described as
found, and if necessary, cleaned and prepared
before examination. For each set of human
remains, forensic anthropologists attempt to
provide a general physical description of the
following factors:
ABSTRACT The discovery of skeletal remains poses
numerous questions that are best answered by those trained
in forensic anthropology. Forensic anthropologists not only
are able to determine at the site whether skeletal remains
are human, but they also employ various methods to
determine the gender, age at death, race, and height of the
deceased. With advances in DNA techniques, forensic
anthropologists will soon be able to derive information from
older and older skeletal remains.
This is the second in a three-part continuing education series on forensics. At the
end of the series, the reader will be able to describe the traditional as well as new
molecular pathology techniques used in detecting sexual assault; describe
techniques used to recover, examine, and identify skeletal remains; and describe
DNA techniques used in the forensic pathology laboratory.
• Gender
• Age at death
.Race
.Height
o
They also try to determine whether the bones
provide evidence of the cause of death, to identify
any individualistic features in the skeleton, and to
estimate the time since death.
Determining Sex
The human pelvis provides the most reliable
means for determining the sex of skeletal
remains. The female pelvis is designed to offer
optimal space for the birth canal, which is
reflected in its morphology and the relationship
of its parts to each other. Although measurements
may be taken to determine the gender of the
remains, an experienced anthropologist often can
tell simply by visual inspection.5 The skull also
can be used to determine the sex of an individual.
JULY 1998
VOLUME 29, NUMBER 7
From the
Anthropology
Department, Clark
College, Vancouver,
Wash, and the
Medical Examiner
Division, Oregon
Department of State
Police, Portland,
Ore.
Reprint requests to
Dr Lundy, Clark
College, 1800 E
McLoughlin Blvd,
Vancouver, WA
98663; or e-mail:
[email protected]
LABORATORY MEDICINE
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Fig 1. Students
excavating a buried
skeleton to learn
forensic exhumation
techniques.
the degree of fusion of the first and second sacral
bodies (S1-S2) to be useful, and the medial clavicular epiphysis in the early twenties.9 In later
adulthood, one can use changes in the pubic symphysis as an indicator of age at death. A series of
casts is available to compare with the unknown
symphysis to estimate age.10 In older adults, we
see degenerative changes in the spine and joints
associated with the aging process. Other methods
include microscopic aging of bone tissue11 and
age-related changes to the ventral ribs.12
Race
As the female progresses from puberty to adulthood, her skull retains many of the prepubertal
traits, such as smoothness and gracility. The male
skull, on the other hand, exhibits more robustness and larger muscle attachment areas, more
pronounced brow ridges, squared lower jaw, etc.
If the skull and pelvis are missing, determining
the sex may be difficult. While various measurements and calculations are available to estimate
sex from long bones and other parts of the skeleton, morphology seems a more accurate feature
than size in determining sex.
Age at Death
The criteria used to estimate age at death depend
on whether the individual is an infant, subadult,
or adult. In fetal and infant remains, age can be
estimated based on the length of certain bones.6
The most reliable means to estimate age in children is the development and eruption of the
teeth.7 We know the developmental pattern and
mean age of eruption for each tooth.
The subadult skeleton also can provide information about the age at death. To allow for
growth, the ends and shafts of long bones are separated by cartilage plates (epiphyses). The cartilage plates disappear and the extremities of the
various long bones fuse at different ages. Similar
processes take place in other bones, such as the
clavicle and pelvis. By knowing the sequence of
this epiphyseal union, we can estimate the age of
an individual.8 In younger adults, I have found
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The word race is an unfortunate label for the population-based physical diversity we see in the
human species around the world. The term is
widely used among the lay public, however.
Methods used to determine the race of skeletal
remains include measurements and observations
of both the skull and the postcranial skeleton.
My experience has been that the skull, especially the facial region, is the most diagnostic for
racial attribution. Nonmetric racial features of
the skull have been outlined by Rhine13 and
include such features as overall shape of the
skull, shape of the nasal region, shape of the
orbits, degree of protrusion of the jaw or prognathism, shape of the lower jaw, and certain features of the teeth, to name a few. Cranial and
facial measurements diagnostic for race have
been reported in a volume on assessing race from
the skeleton,14-16 as have postcranial methods
for determining race.17
Stature
The most common method to estimate living
height from skeletal remains is to use equations
originally developed for this purpose by measuring the lengths of long bones of American casualties from World War II and the Korean War.18'19
We usually measure a leg bone, such as the femur
or tibia, and use the length in the equation listed
for males or females of a particular race. The
result is an estimated living stature, reported as a
range, such as 66 to 68 inches. Another method to
estimate living stature is known as the anatomical
method.20'21 The height of the skull is measured,
along with components of the spine, and the
lengths of the leg bones, including the ankle. To
this "skeletal height" is added a correction factor
for the soft tissues at the joints, scalp, and soles of
the feet. A major drawback of this method is that
it requires a fairly complete skeleton. Methods for
estimating height from the spine have been
reported,22 as have methods for estimating
stature from incomplete long bones.23
While these methods can be fairly accurate,
they rely on antemortem records of height for
comparison. Military data24 indicate that men
tend to overestimate their height more than
women do, and a study of heights reported on
driver's licenses also showed overestimation.25 We
must remember that the statures we calculate
from skeletal remains are estimates.
Fig 2. Healed fractures in ulna and radius with metal plates screwed to bones
to stabilize bones during healing. Evidence of trauma and medical implants
such as these may assist in identifying skeletal remains.
Trauma
Trauma seen in skeletal remains falls into three
categories:
1. Antemortem
2. Perimortem
3. Postmortem
Antemortem trauma includes injuries sustained during life, and evidence of healing usually
exists (Fig 2). Perimortem trauma are injuries
sustained at or about the time of death, and often
contribute to the cause of death (Figs 3 and 4).
Postmortem trauma is that which is sustained
after death, usually by environmental or animal
action. Antemortem injuries, such as healed broken bones or surgical implants may assist in identifying an individual or may provide evidence of
a long-term pattern of injuries in child abuse. For
a general discussion of trauma, the reader should
consult a forensic pathology text such as the one
by DiMaio and DiMaio.26 Trauma in skeletal
remains is addressed by Merbs,27 and postmortem damage and influences are detailed in a
text edited by Haglund and Sorg.28
Fig 3. Cranium reconstructed from 70 pieces showing an entrance gunshot
wound behind the right ear.
Time Since Death
Estimating how long skeletal remains have been
at the location where they are found is one of the
most difficult questions for forensic anthropologists to answer. An estimate of the time since
death can narrow the number of missing persons we compare with the unknown victim.
Fig 4. Reconstructed cranium showing blunt force trauma to the face and head.
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VOLUME 29, NUMBER 7
LABORATORY MEDICINE
However, bones of a person who died 10 years
ago may differ little from those that are from a
person who has been dead only 5 years.
Prompted by a case involving a Civil War grave
mistakenly estimated to be about a year old,29'30
one of the best studies to obtain data on postmortem decomposition and changes has been
undertaken by Professor Bill Bass at the University of Tennessee. Ubelaker discusses current
research on estimating time since death, including the use of insects (forensic entomology).31
Establishing Individual Identity
Test Your
Knowledge
Look for the CE
Update exam on
Forensics (805) in the
August issue of
Laboratory Medicine.
Participants will earn
3 CMLE credit hours.
426
The preferred method for establishing the identity of skeletal remains is by dental identification.
If the anthropologist's general description of the
deceased matches the description of a missing
person, we then ask the missing person's dentist
to provide dental charts and radiographs for
comparison. A forensic odontologist (dentist)
then compares the data to either rule out that the
remains belonged to the missing person or confirm that the unknown and the records represent
the same individual.32
In some cases, the teeth or skull may be missing, requiring alternatives to a dental identification. Postmortem radiographs can be compared
with antemortem radiographs, if available. Cranial anatomy, especially the sinus form can be
compared. Chest radiographs often show some of
the vertebral detail. Evidence of healed fractures
or medical implants may be used to confirm
identity.33 Photographic or video superimposition can be used to superimpose the
unknown skull and a portrait of an individual to
see if they "fit" anatomically.34 Advances in DNA
technology are making it possible to extract DNA
from human bones. This will allow us to compare
the DNA from skeletal remains with the DNA of
family members when we have an idea who the
victim is, but more traditional methods of identification are not available due to incomplete
remains, etc. The military is using DNA to assist
in the identification of MIA/POW remains from
the Vietnam War.
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JULY 1998
Qualifications and Training in Forensic
Anthropology
The usual minimum academic preparation for
work in forensic anthropology is a master's degree
in physical or biological anthropology with additional training in forensic applications. Those
desiring to make forensic anthropology their
major professional focus, however, will normally
seek the doctoral degree and board certification in
forensic anthropology. My advice to those interested in pursuing a graduate education in anthropology and the practice of forensic anthropology is
to contact board-certified forensic anthropologists
who teach at colleges and universities for information about the programs available. A list of such
instructors is available at the American Board of
Forensic Anthropology (ABFA; District of Columbia) Web site: http://www.csuchico.edu/anth/ABFA
[accessed May 22, 1998]. The ABFA also offers a
voluntary certification program. Requirements for
certification include permanent residency in
Canada or the United States, a doctoral degree in
biological/physical anthropology from an accredited university, and 3 years of postdoctoral forensic
experience. The applicant must also submit to a
background investigation to prove his/her good
moral character and pass written and practical
examinations.
Employment
Most forensic anthropologists teach in colleges
and universities or work in museums.
A small number are employed by government agencies. Usually, forensic anthropologists' caseloads35 are insufficient to make a
living from forensic cases alone so most forensic
anthropologists serve as consultants to medical
examiners or coroners and the police. Forensic
science is a fascinating field, with each case presenting new questions and challenges. For me,
the most rewarding aspect of my work is collaboration with forensic pathologists, forensic
odontologists, police investigators, and other
specialists, all cooperating to put the puzzle
pieces together to identify the victim, and often
to help solve a murder.©
Acknowledgments
I wish to thank Shirley Sackman, Tana Hasart, EdD, and Daniel
M. Baer, MD, for their valuable comments and suggestions,
and the anonymous reviewers for their thoughtful input. Very
special thanks are due Patti for her love and support.
Forensic Anthropology. Albuquerque, NM: Maxwell Museum
of Anthropology; 1990:83-90.
18. Trotter M, Gleser G. Estimation of stature from long
limb bones of American whites and Negroes. Am J Phys
Anthropol. 1952;10:463-514.
19. Trotter M, Gleser G. A re-evaluation of stature based on
measurements taken during life and of long bones after death.
References
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Archaeology Books; 1996.
21. Lundy JK. The mathematical versus anatomical methods
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Science. Manchester, England; Manchester University Press;
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3. Stewart TD. Essentials of Forensic Anthropology: Especially 23. Steele DG. Estimation of stature from fragments of long
as Developed in the United States. Springfield, 111: Charles C. limb bones. In: Stewart TD, ed. Personal Identification in Mass
Thomas; 1979.
Disasters. Washington, DC: National Museum of Natural His4. Krogman WM, Iscan MY. The Human Skeleton in Forensic tory; 1970:85-97.
Medicine. Springfield, III: Charles C. Thomas; 1986.
24. Giles E, Hutinson DL. Stature and age-related bias in
5. Sutherland LD, Suchey )M. Use of the ventral arc in pubic
self-reported stature. / Forensic Sci. 1991;36:765-780.
sex determination. / Forensic Sci. 1991;36:501-511.
25. Willey P, Falsetti T. Inaccuracy of height information on
6. Weaver DS. Forensic aspects of fetal and neonatal skeledrivers licenses. / Forensic Sci. 1991;36:813-819.
tons. In: Reichs KJ, ed. Forensic Osteology: Advances in the 26. DiMaio D, DiMaio V. Forensic Pathology. New York, NY:
Identification of Human Remains. Springfield, 111: Charles C.
Elsevier; 1989.
Thomas; 1986;90-100.
27. Merbs CF. Trauma. In: Iscan MY, Kennedy AR, eds.
7. Ash MM. Wheeler's Dental Anatomy, Physiology, and Reconstruction of Life from the Skeleton. New York, NY: Alan R.
Occulsion. Philadelphia, Pa: WB Saunders; 1984:23-39.
Liss; 1989:161-189.
8. McKern TW, Stewart TD. Skeletal Age Changes in Young
28. Haglund WD, Sorg MH, eds. Forensic Taphonomy: The
American Males. Analyzed from the Standpoint of Age Identifi- Postmortem Fate of Human Remains. Boca Raton, Fla: CRC
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29. Bass WM. Time interval since death: a difficult question.
9. Owings Webb PA, Suchey JM. Epiphyseal union of the
In Rathbun TA, Buikstra JE, eds. Human Identification; Case
anterior iliac crest and medial clavicle in a modern multiracial
Studies in Forensic Anthropology. Springfield, 111: Charles C.
sample of American males and females. Am ] Phys Anthropol. Thomas; 1984:136-147.
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30. Bass WM, Meadows L. Time since death and decompo10. Brooks S, Suchey )M. Skeletal age determination based
sition of the human body: variables and observations in case
on the os pubis: a comparison of the Acsadi-Nemeskeri and
and experimental field studies. / Forensic Sci.
Suchey-Brooks methods. Hum Evol. 1990;3:227-238.
1990;35:103-111.
11. Kerley ER, Ubelaker DH. Revisions in the microscopic
31. Ubelaker DH. Taphonomic Applications in Forensic
method of estimating age at death in human cortical bone.
Anthropology. In: Haglund, WD, Sorg MH, eds. Forensic
Am J Phys Anthropol. 1978;49:545-546.
Taphonomy: The Postmortem Fate of Human Remains. Boca
12. Iscan MY, Loth SR. Osteological manifestations of age in
Raton, Fla: CRC Press; 1996;77-90.
the adult. In: Iscan MY, Kennedy AR, eds. Reconstruction of
32. Bowers CM, Bell G, eds. Manual of Forensic Odontology,
Life from the Skeleton. New York, NY; Alan R. Liss; 1989:27-29. 3rd Ed. American Society of Forensic Odontology. Ontario,
13. Rhine S. Non-metric skull racing. In: Gill GW, Rhine S,
Canada: Monticore Publishers; 1997.
eds. Skeletal Attribution of Race: Methods for Forensic Anthro- 33. Lundy JK. Establishing positive identification...when all
pology. Albuquerque, NM: Maxwell Museum of Anthropol- else fails. / Oregon Dent Assoc. 1985;54:21-22.
ogy; 1990:9-20.
34. Webster WP, Brinkhous W. Identification of human
14. Ayers HG, Jantz RL, Moore-Jansen PH. Giles and Elliot
remains using photographic reconstructions. In: Reichs KJ,
race discriminant functions revisited: a test using recent
ed. Forensic Osteology: Advances in the Identification of Human
forensic cases. In: Gill GW, Rhine S, eds. Skeletal Attribution of Remains. Springfield, 111: Charles C. Thomas; 1986:256-289.
Race: Methods for Forensic Anthropology. Albuquerque, NM: 35. Reichs KJ. A professional profile of Diplomates of the
Maxwell Museum of Anthropology; 1990:65-71.
American Board of Forensic Anthropology: 1984-1992. /
15. Gill GW, Gilbert M. Race identification for the midfacial
Forensic Sci. 1995;40:176-182.
skeleton: American blacks and whites. In: Gill GW, Rhine S,
eds. Skeletal Attribution of Race: Methods for Forensic Anthropology. Albuquerque, NM: Maxwell Museum of AnthropolSuggested Reading
ogy; 1990:47-54.
16. Curran B. The application of measures of midfacial pro- For those looking for a more general account of forensic
anthropology, two books will be of interest. Doug Ubelaker's
jection for racial classification. In: Gill GW, Rhine S, eds.
Skeletal Attribution of Race: Methods for Forensic Anthropology. Bones: A Forensic Detective's Casebook (Harper Collins, 1992)
and the late Bill Maples' Dead Men Do Tell Tales: The Strange
Albuquerque, NM: Maxwell Museum of Anthropology;
and Fascinating Cases of a Forensic Anthropologist (Doubieday,
1990:55-57.
1994) are both good reads. For those who might like mystery
17. Iscan MY, Cotton TS. Osteometric assessment of racial
novels with a forensic anthropology focus, try books by Aaron
affinity from multiple sites in the postcranial skeleton. In: Gill
Elkins, the pen name of an anthropologist.
GW, Rhine S, eds. Skeletal Attribution of Race: Methods for
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LABORATO