Chapter 12: Human Remains
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Transcript of Chapter 12: Human Remains
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
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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 MortisSkeletal muscles partially contractJoints stiffen, lock in placeOnset is 10 minutes to several hoursRapid cooling can delay itLasts up to 72 hours
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Chemistry of Rigor Mortis
Living muscle cells use oxygen to burn glycogenAfter death no oxygen— body makes lactic and
pyruvic acidspH falls as acidity increasesAcid promotes a reaction between actin and myosin
which work together to contract the muscleMuscle 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
Temperature Stiffness Approximate Time of body of body Since Death
•Warm
•Warm
•Cold
•Cold
•Not stiff
•Stiff
•Stiff
•Not stiff
•Not dead more than 3 hrs
•Dead between 3 and 8 hrs
•Dead 8 to 30 hours
•Dead more than 30 hours
The rigidity of skeletal muscles after death.
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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 MortisSoon after death, blood is still in vessels, so
pressure on an area pushes the blood outAs 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 MortisAfter death cells release enzyme
(fibrinolysins) that prevents clottingBlood in body stays liquid after death
Permanently won’t clot 30-60 minutes after death
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Algor MortisAlgor 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 MortisBody cools by
Radiation (the higher the body temperature the more heat lost)
Conduction depends on surface contactfaster if in water because enhanced contact
ConvectionWind 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 IntervalsDecomposition occurs in stages
Initial Decay (0-3 days)Autolysis--body’s own enzymes destroys tissueBegins immediately
Putrefaction (4-10 days)Bacteria in gut leak outAnaerobic conditionsBloat from hydrogen sulfide, methane, cadaverine,
putrescine released
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The Smell of The Smell of DeathDeath
putrescine
cadaverine
Breakdown products from amino acids ornithine and lysineAmino acid loses CO2
H = white C = turquoise N = blue
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Determining Long Post Mortem IntervalsBlack Putrefaction (10-20 days)
Body collapsesLiquid seeps into the soil
Butyric Fermentation (20-50 days)Cheesy smell from butyric acidMaggots leaveBeetles arrive
Dry decay (beyond 50 days)Hair is consumed by moths and mitesBones are left
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Longer Term Estimates of
Time of DeathMonitoring ratios of body decay products in the soil
Dr. ArpadVass, ORNL
The Body FarmU. Tenn.
The first well controlled experiments to explore decomposition
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Volatile Fatty Acid Analysis
Results from the Body FarmDepends on temperature
The hotter, the faster the reactions proceedAccumulated Degree Days (sum average daily temp)Decay is linear in Accumulated Degree Days
Depends on whether body was buried or notDecay is faster on the surface
More insect activityWarmer—2 feet down is fairly constant 50-55o F
Decay is slower in acid soilPine forests have very acid soil
Decay is slower if the body is sprayed with insecticide
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Adipocere—Grave
WaxAdipocere 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 is formed under the following conditions: On bodies are not exposed to
insectsIn 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.
Adipocere
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Otzi, the Ice Man
5300 year old bodyFound by hikers in Austrian
AlpsOtzi is primarily now
adipocere
www.spectroscopynow.com/.../MS_Feb08_otzi.jpg
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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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98.4°F – internal body temperature 1.5
Hours since death =
Algor Mortis: Body cooling rate
Livor Mortis: skin discoloration caused by pooling of blood
Rigor Mortis: rigidity of skeletal muscles
A pathologist estimates time of death from these factors.
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
Summary of Decomposition
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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 bloatingThe 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 fermentationCadaver 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).
Summary of Stages of Death
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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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OsteologyStudy of bones206 bones in an adult humanFunction 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 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
Sagittal suture
Lambodial Coronal
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Age Determination Using Basilar Suture
Basilar Suture Technically known as the
synchondrosis spheno-occipitalis, 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 Unionof Medial Clavicle
Male Female
Non-union without separate epiphysis
21 or younger 20 or younger
Non-union with separate epiphysis
16-21 17-20
Partial union 17-30 17-33
Complete union 21 or older 20 or older
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Age Determination Using Epiphysis
Stage of Unionof the Iliac Crest
Male Female
Non-union without separate epiphysis
16 or younger 11 or younger
Non-union with separate epiphysis
13-19 14-15
Partial union 14-23 14-23
Complete union 17 or older 18 or older
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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).
Male Female
Sub Pubic Angle
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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 HeightThe 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 femur x 2.21 +61.41tibia x 2.39 + 81.68 tibia x 2.53 + 72.57humerus x 2.97 + 73.57 humerus x 3.14 + 64.97radius x 3.65 + 80.40 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 andIdentification
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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Anthropologistat Work
This anthropologist ishard at work dustingaway 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 uponto give information on the life and deathof humans and animals in uniquecircumstances, 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 Farmwww.crimelibrary.com/criminal_mind/forensics/bill_bass/4.html
On forensic artists:http://origin-www.crimelibrary.com/criminal_mind/forensics/art/1.html