Chapter 13: Human Remains “There is a brief but very informative biography of an individual contained within the skeleton, if you know how to read it…”

Chapter 13: 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

Forensic Science: Fundamentals & Investigations, Chapter 13 2

Chapter 13 Forensic Anthropology: What We Learn from Bones By the end of this chapter you will be able to:

o Describe how bone is formed o Distinguish between male and female skeletal

remains o Explain how bones contain a record of injuries

and disease

All Rights Reserved South-Western / Cengage Learning © 2012, 2009


Chapter 13 Forensic Anthropology: What We Learn from Bones By the end of this chapter you will be able to:

o Describe how a person’s approximate age could be determined

o Explain the differences in facial structures among races

o Discuss the role of mitochondrial DNA in bone identification

Kendall/Hunt Publishing Company

4

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

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.

algor mortis: postmortem changes that cause a body to lose heat (occurs 15 min – 2 hours after death)

rigor mortis: the shortening and stiffening of muscles that occurs after Death.

livor mortis: pooling or settling of blood in areas of the body closest to the ground 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

Generally the body cools 1 to 1.5 degrees Fahrenheit per hour until it reaches the surrounding temperature.

Temperature of the surrounding environment . Type of clothing on the body, Wetness of the clothing, Air movement, Layers of clothing, Size of the individual may affect rate


Forensic AnthropologyForensic Anthropology

o Anthropology—the scientific study of all aspects of human development and interaction

o Physical anthropology—studies human differences

o Forensic anthropology—studies these identifying characteristics on the remains of an individual

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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


Historical Development Historical Development

o 1800s—scientists begin studying skulls o 1897—sausage maker’s wife murdered; bone

fragments found in his factoryo 1932—the FBI opens the first crime labo Smithsonian Institution partners with FBI


Historical Development Historical Development

o 1939—William Krogman publishes Guide to the Identification of Human Skeletal Material

o Soldiers killed in World War II are identified using anthropologic techniques

o DNA—new tool to analyze skeletons


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Study 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

(Regular Pattern) (Chaotic Pattern)

OsteologyOsteons – holes in bones to carry blood supply: Animal v. Human


Characteristics of Bone

o Bones are aliveo Marrow—creates blood cellso Hormones affect the amount of

calcium in the blood and bones


Development of Bone Development of Bone

o Osteoblast cells—where bones originateo Ossification—when osteoblast cells migrate

to the center of cartilage production and deposit minerals

o Life cycle—bone is deposited, breaks down, and replaced

o Osteoclasts—the 2nd type of bone cell, specialized to dissolve bone


Development of Bone Development of Bone

o Osteoclasts—the 2nd type of bone cell • Specialized to dissolve bone • Allows bones to reshape as they grow• Balances calcium levels in blood• Removes cellular wastes and debris from bones

o Osteoporosis—a deficiency of calcium in the bones


How Bones Connect How Bones Connect

cartilage—wraps the ends of bones for protection and prevents scraping



ligaments—bands that connect two or more bones together



tendons—connect muscle to bone


Aging of Bone Aging of Bone

o Under 30 years of age—bones increase in size

o Over 30—process reverseso Exercise slows deterioration


What Bones Can Tell Us What Bones Can Tell Us

o Osteobiography—bones contain a record of the physical life

o Analyzing bones reveals clues to gender, age, height, and health

o Examples:• In a right-handed person, right arm bones might

be slightly larger than the bones of the left arm• X-rays may identify prior fractures, pins, artificial

joints


Gender—Gender—SkullSkull

Male Characteristics

Trait

Female Characteristics

More square Shape of eye More rounded

More square Mandible shape from underside

More V-shaped

Thick and larger Upper brow ridge

Thin and smaller


Gender—Skull Gender—Skull

Male Characteristics

Trait

Female Characteristics

Present Occipital protuberance

Absent

Low and sloping Frontal bone Higher and more rounded

Rough and bumpy

Surface of skull

Smooth

Straight Ramus of mandible

Slanting

Rough and bumpy

Nuchal crest Smooth


Gender—Skull Gender—Skull

o Is the female skull smoother than the male’s? o Which frontal bone is lower and sloping? o Are the male’s eye orbits more circular? o Which jaw is more square, with an angle that

is closer to 90o?


Gender—Gender—PelvisPelvis

o An easy method to determine gender o The surface of a woman’s pelvis can be

scared o The sub pubic angle of the female pelvis is

greater than 90o; the male’s, less

Male Female

Sub Pubic Angle

Kendall/Hunt Publishing Company27

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.


GenderGender—Thigh bones—Thigh bones

The male femur is thicker and joins the pelvis at a straighter angle than the female femur


AgeAge—Skull —Skull

o By about age 30, the suture at the back of the skull closes

o By about age 32, the suture running across the top of the skull, back to front, closes

o By about age 50, the suture running side to side over the top of the skull, near the front, closes


Age Age

o At birth—450+ bones in the skeleton

o Adults— 206 boneso Epiphysis line—appears where

cartilage is replaced by boneo When the cartilage is fully replaced,

the line is no longer visibleo This information can be used to

approximate a skeleton’s age


AgeAge—Epiphysis —Epiphysis


Age—Age—Epiphysis Epiphysis


HeightHeight

o An estimate of height can be made by measuring one of the long bones

o Gender and race is taken into considerationo (See Textbook for Height estimation formula)


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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


How to Distinguish RaceHow to Distinguish Race

o Shape of the eye socketso Absence or presence of a nasal spineo Measurements of the nasal indexo Prognathism (Projection of upper jaw beyond lower jaw)o Width of the faceo Angulation of the jaw and faceo (see textbook figure 13-21 for comparison of characteristics)


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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


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.


Facial Reconstruction Facial Reconstruction

o Facial muscles follow the contour of the skullo A face can be rebuilt from just skeletal remains

• Facial markers are positioned at critical locations• Clay is contoured to follow the height of the markers

o Computer programs perform a similar functiono Computer programs also can “age” missing

persons and criminals


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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Animal Facial RestorationDetermining what T Rex looked like using the bone formation.From this: To this:


DNADNA Evidence Evidence

o Bone contains little nuclear DNA but it does contain mitochondrial DNA

o Nuclear DNA degenerates before mitochondrial DNA

o Mitochondrial DNA is inherited only from the mother

o Compare results with living relatives on the mother’s side of the family


Skeletal Skeletal TraumaTrauma Analysis Analysis

o Forensic anthropologists determine if damage to bones occurred before or after death

o Distinct patterns exist for damage by• Environment • Sharp-force trauma • Blunt-force trauma • Gunshot wounds• Knife wounds


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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.


. . . . . . . . . . . . . Summary . . . . . . . . . . . . . . . . . Summary . . . .

o Bones are alive and carry on all life functions. o Bone condition can tell investigators about a

person’s health and nutrition during life. o Male and female skeletons differ. o The age of a person at death can be estimated

by analyzing bones.


. . . . . . . . . . . . . . . . . Summary . . . . . . . . . . . . . . . . . Summary

o A person’s height can be estimated by the length of long bones.

o Facial reconstruction is possible to some extent.

o Mitochondrial DNA can be extracted to help identify skeletal remains.

o Skeletal trauma analysis examines bones for evidence of damage.

Chapter 13: Human Remains “There is a brief but very informative biography of an individual contained within the skeleton, if you know how to read it…”

Documents

death slide

body temperature

forensic anthropologist

hours of death

death rigor mortis

individual slide

forensic science

algor mortis algor mortis