Transcript Human Remains ppt

Chapter 12:
Human Remains
“There is a brief but very informative
biography of an individual contained within
the skeleton, if you know how to read it…”
—Clyde Snow, Forensic Anthropologist
The Pathologist
 Determines the time of death. This can
be done most accurately if the body is
found within the first 24 hours of death
 Uses certain indicators such as algor,
livor and rigor mortis.
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Rigor Mortis
Skeletal muscles partially contract
Joints stiffen, lock in place
Onset is 10 minutes to several hours
Rapid cooling can delay it
Lasts up to 72 hours
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Chemistry of
Rigor Mortis
Living muscle cells use oxygen to burn glycogen
After death no oxygen— body makes lactic and
pyruvic acids
pH falls as acidity increases
Acid promotes a reaction between actin and
myosin which work together to contract the
muscle
Muscle shortens until all ATP and acetylcholine is
used up
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Muscle
Contraction
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End of Rigor
Mortis
The muscles relax when the body starts to
decompose and the fibers begin to break
down
Autolysis- Digestive enzymes are released
as the cells begin to disintegrate, destroying
the muscle fibers
Meat is more tender after rigor mortis has
passed (Aged Beef?)
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Rigor Mortis
The rigidity of skeletal muscles after death.
Temperature
of body
Stiffness
of body
Approximate Time
Since Death
•Warm
•Not stiff
•Not dead more than 3 hrs
•Warm
•Stiff
•Dead between 3 and 8 hrs
•Cold
•Stiff
•Dead 8 to 30 hours
•Cold
•Not stiff
•Dead more than 30 hours
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Livor Mortis
 Livor mortis is the settling of blood, resulting
in a reddish or purplish color pattern.
 Lividity can indicate the position of the body
after death. When lividity becomes fixed,
then the distribution of the pattern will not
change even if the body’s position is altered.
 Lividity usually becomes fixed between 10
and 15 hours after death.
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Livor Mortis
Soon after death, blood is still in vessels, so
pressure on an area pushes the blood out
As time goes on blood vessels break down as do
blood cells and hemoglobin break down pigment
moves out into the tissues
Contact pallor is caused by pressure or
constrictive clothing prevents blood from pooling
locally
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Livor Mortis
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Livor Mortis
After death cells release enzyme
(fibrinolysins) that prevents clotting
Blood in body stays liquid after death
Permanently won’t clot 30-60 minutes after
death
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Algor Mortis
Algor mortis is the cooling rate of the body after death.
At a crime scene, the body temperature is obtained
through:
 Rectal temperature
 Liver temperature
Glaister equation:
98.4°F - internal temperature/1.5 = hours elapsed since death
Generally the body cools 1 to 1.5 degrees Fahrenheit
per hour until it reaches the surrounding temperature.
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Algor Mortis
Body cools by
Radiation
(the higher the body temperature the more heat lost)
Conduction depends on surface contact
faster if in water because enhanced contact
Convection
Wind cools faster
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Effects that Influence
Algor Mortis
 Temperature of the surrounding environment
 Type of clothing on the body
 Clothing Insulates body from heat loss




Wetness of the clothing
Air movement
Layers of clothing
Size of the individual
 Obesity:Fat insulates, temperature falls more slowly
 Ratio of surface area to volume: Children, thin people cool
faster
 In water? Cooling is faster since water is a better
conductor of heat than air
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Determining Long
Post Mortem
Intervals
Decomposition occurs in stages
Initial Decay (0-3 days)
Autolysis--body’s own enzymes destroys tissue
Begins immediately
Putrefaction (4-10 days)
Bacteria in gut leak out
Anaerobic conditions
Bloat from hydrogen sulfide, methane, cadaverine,
putrescine released
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The Smell of
Death
putrescine
cadaverine
Breakdown products from amino acids ornithine and lysine
Amino acid loses CO2
H = white C = turquoise N = blue
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Determining Long
Post Mortem
Intervals
Black Putrefaction (10-20 days)
Body collapses
Liquid seeps into the soil
Butyric Fermentation (20-50 days)
Cheesy smell from butyric acid
Maggots leave
Beetles arrive
Dry decay (beyond 50 days)
Hair is consumed by moths and mites
Bones are left
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Longer Term
Estimates of Time
of Death
 Monitoring ratios of body decay products in the soil
Dr. Arpad
Vass, ORNL
The Body Farm
U. Tenn.
The first well
controlled
experiments to
explore
decomposition
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Volatile Fatty Acid
Analysis
Results from the Body
Farm
Depends on temperature
The hotter, the faster the reactions proceed
Accumulated Degree Days (sum average daily temp)
Decay is linear in Accumulated Degree Days
Depends on whether body was buried or not
Decay is faster on the surface
More insect activity
Warmer—2 feet down is fairly constant 50-55o F
Decay is slower in acid soil
Pine forests have very acid soil
Decay is slower if the body is sprayed with
insecticide
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Adipocere—
Grave Wax
Adipocere is a wax-like substance formed by the
hydrolysis of fat to fatty acids and soaps in
presence of bacterial enzymes.
It is resistant to bacteria and slows further
decomposition.
Formation begins within a month of death, and in
the absence of air it can last for centuries.
Formation can occur in embalmed or untreated
corpses.
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Adipocere
Adipocere is formed under the
following conditions:
On bodies are not exposed to
insects
In a moist, airless environment
(bottom of a lake, wet ground)
Prominent on cheeks, buttocks,
stomach, breasts (areas with lots
of fat)
An exposed, infested body (with
insects), or a body in a warm
environment is unlikely to form
deposits of adipocere.
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Otzi, the Ice
Man
5300 year old body
Found by hikers in Austrian
Alps
Otzi is primarily now
adipocere
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www.spectroscopynow.com/.../MS_Feb08_otzi.jpg
Adipocere –
Grave Wax
Over a timescale of centuries, adipocere in sealed
airtight containers (such as lead-lined coffins used
by the Romans) can turn into “body liquor" - a
brown/orange fatty liquid that may be highly
infectious.
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Summary of Decomposition
Algor Mortis: Body cooling rate
Hours since death =
98.4°F – internal body temperature
1.5
Livor Mortis: skin discoloration caused by pooling of blood
Rigor Mortis: rigidity of skeletal muscles
Temperature of body
Stiffness of body
Time since death
Warm
Not stiff
Not dead more than 3 hours
Warm
Stiff
Dead between 3 and 8 hours
Cold
Stiff
Dead between 8 and 36 hours
Cold
Not stiff
Dead for more than 36 hours
A pathologist estimates time of death from these factors.
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Summary of Stages of Death
Stage
Description
Initial or fresh decay (autolysis)
The cadaver appears fresh externally but is
decomposing internally due to the activities of
bacteria present before death (0–4 days).
Putrefaction or bloating
The cadaver is swollen by gas produced internally,
accompanied by the odor of decaying flesh (4–10
days).
Black putrefaction
Flesh of creamy consistency, with exposed body
parts black. Body collapses as gases escape.
Fluids drain from body. Odor of decay very strong
(10–20 days).
Butyric fermentation
Cadaver drying out. Some flesh remains
at first; cheesy odor from butyric acid
(20–50 days).
Dry decay (diagenesis)
Cadaver almost dry; slow rate of decay. May
mummify (50–365 days).
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Forensic
Anthropology
Forensic anthropology is a
type of applied anthropology
that specializes in the
changes and variations in the
human skeleton for the
purpose of legal inquiry
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Forensic
Anthropology
 A forensic anthropologist may provide basic identification
information of skeletonized or badly decomposed
remains.
 From a whole bone or part of a bone, the scientist may
be able to determine:
 An age range
 Sex
 Race
 Approximate height
 Cause of death, disease, or anomaly
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Osteology
Study of bones
206 bones in an adult human
Function of bones:






Provides structure and rigidity
Protects soft tissue and organs
Serves as an attachment for muscles
Produces blood cells
Serves as a storage area for minerals
Can detoxify the body by removing heavy metals
and other foreign elements from the blood
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Age Determination
Most accurate estimations from:
 Teeth
 Epiphyses or growth plates
 Pubic symphysis
 Cranial sutures: the three major cranial sutures appear as distinct lines in
youth and gradually close from the inside out.
Investigators always use an age range because of the
variation in people and how they age.The investigator does
not want to eliminate any possibilities for identification.
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Age Determination
Using Cranial Sutures
Sagittal suture
Sagittal suture completely closed
 Males—26 or older
 Female—29 or older
Sagittal suture is complete open
 Male—less than 32
 Female—less than 35
Complete closure of all three
major sutures
 Male—over 35
 Female—over 50
Lambodial
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Coronal
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Age Determination
Using Basilar Suture
 Basilar Suture
 Technically known as the
synchondrosis sphenooccipitalis, closes in
females as young as 14
and in males as young
as 16. If the suture is
open, the individual is
generally considered 18
or younger.
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Age Determination
Using Epiphysis
Stage of Union
of Medial Clavicle
Male
Female
21 or younger
20 or younger
Non-union with separate
epiphysis
16-21
17-20
Partial union
17-30
17-33
21 or older
20 or older
Non-union without
separate epiphysis
Complete union
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Age Determination
Using Epiphysis
Stage of Union
of the Iliac Crest
Male
Female
16 or younger
11 or younger
Non-union with separate
epiphysis
13-19
14-15
Partial union
14-23
14-23
17 or older
18 or older
Non-union without
separate epiphysis
Complete union
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Gender Differences
in Bones
The pelvis of the female is wider. Males have
a narrow subpubic angle (A) and a narrow
pubic body (B).
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Male
Female
Sub Pubic Angle
Gender Differences
The ribcage and shoulders
of males are generally
wider and larger than that
of females. In addition,
about one person in
twenty has an extra rib.
This is more common in
males than in females.
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Gender Differences
In males the index finger is sometimes shorter than the
third finger. In females, the first finger is sometimes
longer than the third finger. This is not often used as an
indicator of gender as there are many exceptions.
Is this a male or female hand
according to the above rule?
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Race
Race is difficult to determine from most skeletal
remains, especially since pure races are becoming
uncommon. An experienced forensic anthropologist
can generally place skulls into one of three groups:
 Caucasian—European, Middle Eastern, and Indian
descent
 Negroid—African, Aborigine, and Melanesian descent
 Mongoloid—Asian, Native American and Polynesian
descent
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Race
Characteristics
 Caucasoids—have a long, narrow nasal aperture,
a triangular palate, oval orbits, narrow zygomatic
arches and narrow mandibles.
 Negroids—have a wide nasal aperture, a
rectangular palate, square orbits, and more
pronounced zygomatic arches. The long bones are
longer, have less curvature and greater density.
 Mongoloids—have a more rounded nasal
aperture, a parabolic palate, rounded orbits, wide
zygomatic arches and more pointed mandibles.
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What differences do you notice
between these three skulls?
Can you determine race?
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Estimation of
Height
The height of a person can be calculated by using the length of
certain long bones, including the femur, tibia, humerus, and radius.
Below are the equations to determine average measurements for
both male and female. (All measurements are in centimeters)
Male
Female
femur x 2.23 + 69.08
tibia x 2.39 + 81.68
humerus x 2.97 + 73.57
radius x 3.65 + 80.40
femur x 2.21 +61.41
tibia x 2.53 + 72.57
humerus x 3.14 + 64.97
radius x 3.87 + 73.50
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Odontology
The identity of an individual can
be determined by comparing a
person’s teeth to their dental
records. Unusual features
including the number and types
of teeth and fillings, the spacing
of the teeth, and/or special
dental work (bridges, false
teeth, root canals) help to make
a positive identification.
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Odontology and
Identification
Teeth are often used for body
identification because:
 They are the hardest substances in the body
 They are unique to the individual
 X-rays are a good record of teeth
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Facial Restoration
After determining the sex, age,
and race of an individual, facial
features can be built upon a
skull to assist in identification.
Erasers are used to make tissue
depths at various points on the
skull. Clay is used to build
around these markers and facial
features are molded.
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Steps in Facial
Reconstruction
With a skull:
 Establish age, sex and race
 Plot landmarks for tissue
thickness
 Plot origin and insertion points
for muscles
 Plot landmarks for facial
features
 Select a dataset and mount
markers for tissue thickness
 Mount the eyes
 Model muscles on skull
 Add fatty tissue around
eyes and lacrimal glands
 Add eyelids
 Add the nose
 Add the parotid gland
 Add the ears
 Cover all with layers of
skin
 Detail the face
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One Final Product
John List killed his entire family, moved to a new town and
assumed a new identity. Seventeen years later, Frank Bender
reconstructed what he believed List would look like. It was
shown on America’s Most Wanted, and he was turned in by
the viewers almost immediately. . . looking very much like the
reconstruction.
Check out more about this story on CourtTV’s crime library:
www.crimelibrary.com/notorious_murders/family/list/1.html
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People in the News
Bill Bass is a forensic anthropologist who has
assisted law enforcement with hundreds of
cases. He established the world’s first and only
laboratory devoted to the study of human
decomposition at the University of Tennessee’s
Anthropology Research Facility.
It is known as “the body farm.”
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The Body Farm
The nickname of a two and a half acre research facility in
Tennessee developed in 1980 by Bill Bass where bodies are
placed in various conditions and allowed to decompose. Its
main purpose is to observe and understand the processes
and timetable of postmortem decay. Over the years it has
helped to improve the ability to determine "time since death"
in murder cases.
Hic locus est ubi mortui viveuntes docent.
This is the place where the dead teach the living.
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Anthropologist
at Work
This anthropologist is
hard at work dusting
away material from
these imbedded
bones.
Picture taken at
Chicago’s Museum
of Natural History
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More Applications
Forensic experts may be called upon
to give information on the life and death
of humans and animals in unique
circumstances, including:
 Mass Murder (Oklahoma bombing, plane crashes, World Trade)
 Earlier man (mummies, Iceman, Lindow man)
 Historical Significance (Holocaust, uncertain death of famous
people)
 Prehistoric Animals (Dinosaurs)
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Animal Facial
Restoration
Determining what T Rex looked like using the bone formation.
From this:
To this:
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More Information
For additional information on Bill Bass and the Body Farm
www.crimelibrary.com/criminal_mind/forensics/bill_bass/4.html
On forensic artists:
http://origin-www.crimelibrary.com/criminal_mind/forensics/art/1.html
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