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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…”

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Presentation on theme: "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…”"— Presentation transcript:

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2 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

3 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

4 Forensic Science: Fundamentals & Investigations, Chapter 13 3 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

5 Ken dall/ Hunt Publi shin g Com pany 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.

6 Ken dall/ Hunt Publi shin g Com pany 5 Rigor Mortis Temperature Stiffness Approximate Time of body of body Since Death Warm Cold Not 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.

7 Ken dall/ Hunt Publi shin g Com pany 6 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.

8 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

9 Ken dall/ Hunt Publi shin g Com pany 8 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

10 Forensic Science: Fundamentals & Investigations, Chapter 13 9 Forensic 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

11 10 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

12 Forensic Science: Fundamentals & Investigations, Chapter 13 11 Historical Development o 1800s—scientists begin studying skulls o 1897—sausage maker’s wife murdered; bone fragments found in his factory o 1932—the FBI opens the first crime lab o Smithsonian Institution partners with FBI

13 Forensic Science: Fundamentals & Investigations, Chapter 13 12 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

14 Ken dall/ Hunt Publi shin g Com pany 13 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 (Regular Pattern) (Chaotic Pattern) Osteology Osteons – holes in bones to carry blood supply: Animal v. Human

15 Forensic Science: Fundamentals & Investigations, Chapter 13 14 Characteristics of Bone o Bones are alive o Marrow—creates blood cells o Hormones affect the amount of calcium in the blood and bones

16 Forensic Science: Fundamentals & Investigations, Chapter 13 15 Development of Bone o Osteoblast cells—where bones originate o 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 2 nd type of bone cell, specialized to dissolve bone

17 Forensic Science: Fundamentals & Investigations, Chapter 13 16 Development of Bone o Osteoclasts—the 2 nd 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

18 Forensic Science: Fundamentals & Investigations, Chapter 13 17 How Bones Connect cartilage—wraps the ends of bones for protection and prevents scraping

19 Forensic Science: Fundamentals & Investigations, Chapter 13 18 How Bones Connect ligaments—bands that connect two or more bones together

20 Forensic Science: Fundamentals & Investigations, Chapter 13 19 How Bones Connect tendons—connect muscle to bone

21 Forensic Science: Fundamentals & Investigations, Chapter 13 20 Aging of Bone o Under 30 years of age—bones increase in size o Over 30—process reverses o Exercise slows deterioration

22 Forensic Science: Fundamentals & Investigations, Chapter 13 21 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

23 Forensic Science: Fundamentals & Investigations, Chapter 13 22 Gender—Skull Male Characteristics Trait Female Characteristics More squareShape of eyeMore rounded More squareMandible shape from underside More V-shaped Thick and largerUpper brow ridge Thin and smaller

24 Forensic Science: Fundamentals & Investigations, Chapter 13 23 Gender—Skull Male Characteristics Trait Female Characteristics PresentOccipital protuberance Absent Low and slopingFrontal boneHigher and more rounded Rough and bumpy Surface of skull Smooth StraightRamus of mandible Slanting Rough and bumpy Nuchal crestSmooth

25 Forensic Science: Fundamentals & Investigations, Chapter 13 24 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 90 o ?

26 Forensic Science: Fundamentals & Investigations, Chapter 13 25 Gender—Pelvis 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 90 o ; the male’s, less

27 Male Female Sub Pubic Angle

28 Kendall/Hunt Publishing Company 27 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.

29 Forensic Science: Fundamentals & Investigations, Chapter 13 28 Gender—Thigh bones The male femur is thicker and joins the pelvis at a straighter angle than the female femur

30 Forensic Science: Fundamentals & Investigations, Chapter 13 29 Age—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

31 Forensic Science: Fundamentals & Investigations, Chapter 13 30 Age o At birth—450+ bones in the skeleton o Adults— 206 bones o Epiphysis line—appears where cartilage is replaced by bone o When the cartilage is fully replaced, the line is no longer visible o This information can be used to approximate a skeleton’s age

32 Forensic Science: Fundamentals & Investigations, Chapter 13 31 Age—Epiphysis

33 Forensic Science: Fundamentals & Investigations, Chapter 13 32 Age— Epiphysis

34 Forensic Science: Fundamentals & Investigations, Chapter 13 33 Height o An estimate of height can be made by measuring one of the long bones o Gender and race is taken into consideration o (See Textbook for Height estimation formula)

35 Ken dall/ Hunt Publi shin g Com pany 34 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

36 Forensic Science: Fundamentals & Investigations, Chapter 13 35 How to Distinguish Race o Shape of the eye sockets o Absence or presence of a nasal spine o Measurements of the nasal index o Prognathism ( Projection of upper jaw beyond lower jaw ) o Width of the face o Angulation of the jaw and face o (see textbook figure 13-21 for comparison of characteristics)

37 Ken dall/ Hunt Publi shin g Com pany 36 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

38 Kendall/Hunt Publishing Company 37 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.

39 Forensic Science: Fundamentals & Investigations, Chapter 13 38 Facial Reconstruction o Facial muscles follow the contour of the skull o 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 function o Computer programs also can “age” missing persons and criminals

40 Kendall/Hunt Publishing Company 39 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.

41 Ken dall/ Hunt Publi shin g Com pany 40 Animal Facial Restoration Determining what T Rex looked like using the bone formation. From this: To this:

42 Forensic Science: Fundamentals & Investigations, Chapter 13 41 DNA 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

43 Forensic Science: Fundamentals & Investigations, Chapter 13 42 Skeletal Trauma 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

44 Ken dall/ Hunt Publi shin g Com pany 43 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.

45 Forensic Science: Fundamentals & Investigations, Chapter 13 44............. 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.

46 Forensic Science: Fundamentals & Investigations, Chapter 13 45................. 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.


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