Transcript Forensic Anthropology

Human Remains
The Postmortem Interval:
Determining the Time of Death
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Pathologist usually determines
Done most accurately within the first
24 hrs of death
Algor mortis
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Cooling rate of the body after death
Glaister formula
– H=(98°F-internal temperature)/1.5
– Body generally cools 1 to 1.5 degrees
per hour until it reaches environmental
temp.
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Factors to consider
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Temp. of environment
Type of clothing
Clothing wet or dry
Air movement
Layers of clothing
Surface area to body mass
Livor Mortis
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Pooling of blood after the heart stops,
caused by gravity
Can indicate the position of the body at the
time of death
None found in areas of the body that touch
the ground
Begins within ½ hr after death
After 12 hrs discoloration will not move
Rigor Mortis
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Rigidity of the skeletal muscles after death
due to buildup of calcium ions
Occurs within 2 or 3 hrs after death
Gone within 30 hrs when muscle protein
begins decomposing
Affected by temp., dehydration, condition of
muscles, and use prior to death
Decomposition
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Gradual breakdown of dead organic
matter which releases elements and
compounds
Caused by bacteria and fungi
autolysis occurs as well
Stages of decomposition
1. Fresh
2. Initial decay
3. Putrefaction
4. Black putrefaction
5. Butyric
fermentation
6. Dry decay
Rate of decomposition
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Dependent on environmental factors
Fastest in warm, humid areas
Slowest in cold, arid areas
Results in either skeletonization or
mummification
Forensic Anthropology
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Anthropology – study of humankind
including anatomy, variability,
evolution, and culture
Forensic anthropology – specializes in
the human skeletal system and its
changes and variations, for purposes
of legal inquiry
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Bodies are decomposed, badly
burned, or mummified
Identification of crime victims
Cause of death
Time of death (approx.)
Demographics
Human vs. Animal Bones
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Osteology – study of bones
Can be determined by visual
inspection
Can be determined through
microscopic examination (osteons
irregular pattern in humans)
The Skeleton
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Adult human has 206 bones
Classified as long (arms), short (wrist),
flat (scapula), or irregular (vertebrae)
Estimating Height Using Long
Bones
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See page 275
Sex Determination
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Most obvious differences in pubis, sacrum,
and ilium
Also shape of skull and mandible and size
of occipital prtuberance
Size of bones
Sacrum is straighter in females
Space in middle of pelvic bone is larger in
women
Characteristics of Pubic Bone
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Width of arch (larger in fem)
Width of body (wider in fem)
Existence of well-defined ventral arc
(not present in male)
Determining Sex Using Skull
Features
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Angle of mandible
Space at between mandible
attachment
Size of cranial bones
Determining Age
page 281
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Teeth erupting,
bones growing
Closure of cranial
sutures
Changes in
epiphyses
Age based on cranial sutures
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Sagittal
Coronal
Lambodial
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Sagittal completely
closed
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Male 26 or older
Female 28 or older
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All three major
sutures completely
closed
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Male 35 or older
Female 50 or older
Age based on pubic bone
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Pattern on symphysis
– regular rows or furrows in younger
individuals
– smooth with an oval surface
– Breakdown of the bone in older
individuals
Determining of Race
p. 286-287
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Caucasoid
– European, Middle Eastern, East Indian
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Negroid
– African, Aborigine, Melanesian
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Mongoloids
– Asian, Native American, Polynesian
Caucasoid
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Long, narrow nasal aperture
Triangular palate
Oval orbits
Narrow zygomatic arches
Narrow mandibles
Negroid
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Wide nasal aperture
Rectangular palate
Square orbits
More pronounced zygomatic arches
Long bones are longer, less curvature,
greater density
Mongoloid
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More rounded nasal aperture
Parabolic palate
Rounded orbits
Wide zygomatic arches
More pointed mandibles
Facial Reconstruction
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Uses standard tissue thickness and
facial muscles to build a new face on a
skull
Not completely accurate, but has
proven helpful
Steps in facial reconstruction
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Establish gender,
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age, race
Glue markers on skull •
for tissue thickness
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Mark muscle insertion
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Mount eyes in
sockets
Apply clay
Determine nose and
mouth thickness and
width
Cover the skull with
layers of skin and
add detail
After reconstruction
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Photographs distributed
Skull-photo superimpositions
Proportion most important
Cause of death
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Stab wounds
Bullet holes
Blows to the head
Tool mark
Bone Anomalies
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Healed breaks or fractures
Joint replacements
Osteoporosis
Arthritis
Classwork/Homework
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Page 289-290 #2-18 even only!!
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