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Chapter Three (44-53) A Question of Identity. Chapter 3 HWC 1.Name ONE thing you can determine about a victim by studying their skeletal remains. (Q.1)

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Presentation on theme: "Chapter Three (44-53) A Question of Identity. Chapter 3 HWC 1.Name ONE thing you can determine about a victim by studying their skeletal remains. (Q.1)"— Presentation transcript:

1 Chapter Three (44-53) A Question of Identity

2 Chapter 3 HWC 1.Name ONE thing you can determine about a victim by studying their skeletal remains. (Q.1) 2.How will a warm and dry environment affect the decaying process? (Q.7) 3.How will a victim who is young and overweight decay? (Q.7) 4.Which part of a the body is used to determine the gender of a skeleton? (Q.8) 5.What is the most difficult part of a facial reconstruction? (Q.11)

3 Name all of the ways you can think of to positively identify a body: Match facial photograph to missing persons and have family confirm. Use artifacts: – Wallet or I.D. – Rings, jewlery – Distinctive clothing – Homemade coffin, Distinguishing marks: scars, birthmarks, tatoos Wounds or disease Fingerprints Teeth Skeletal remains

4 1. What types of things can be identified by studying a skeleton? Age and sex State of health Physical size Racial origin Serious wounds

5 3. When did forensic medicine emerge as a course of study in Europe? When was the first Professor of Medical Jurisprudence appointed in the USA? Emerged in the mid 17 th C. In 1813, NYC surgeon James S. Stringham was appointed

6 4. During an autopsy, what abnormalities does a pathologist look for? (hint: look under the heading “Telltale Clues”) Evidence of stomach ulcers, kidney stones or gallstones Degeneration of the joints due to arthritis Constriction of the arteries Signs of any earlier traumas or surgical procedures  these can be referenced against medical records to prove identity Tattoos, birthmarks

7 5. What types of information can be determined by examining a victim’s blood? Analysis of blood will reveal conditions such as anemia or malaria 6. How might the occupation or social status of a victim be determined? Occupational or social status can be suggested by stains, calluses, or scars on the hands of those who do manual labour.

8 7. Explain, in detail, how different environments or body types affect the condition of a dead body? Note: you are looking for SIX different variables. i.Dry and warm  tissues dry out before decay sets in. In some cases, the body shrivels up, but the structure of the face, hair and other distinguishing features remains in tact.

9 ii. Humid and warm  bacteria thrives and speeds up the process of decay

10 iii. Young or overweight people  tend to decay more quickly due to greater proportions of fat iv. Victim suffering from infectious disease  decay is also accelerated v. Victim who has been poisoned  decay is delayed because some poisons affect the organisms that would normally carry out the process

11 8. Which parts of the human skeleton are used to determine its sex? The pubic bone  its shape, subpubic angle, and the presence of the ventral arc are most commonly used. Males also tend to have more a pronounced superorbital crest (the ride of bone above the eye socket)

12 Determining Age Teeth – 32 permanent teeth means at least 12 years old. – Wisdom teeth mean at least 18 years old. – General wear

13 Determining Age Skull – An infant’s skull is in several pieces. – Over time, pieces fuse together along suture lines. – Problem: fusing occurs in a widely variable pattern.

14 Determining Age Long Bones: tibia, fibia, femur, humerus, radius, ulna. – The growth plates in the bones remain open as body increases in size. – Usually complete at age 25.

15 Determining Age Pelvis – The symphysis is a thin band of cartilage that attaches your pelvis to your spinal column. – When young, it has a zig-zag pattern. – Begins to straighten as you age, finishing at age 50

16 Determining Age Ribs – Sternal Areas: where ribs join the breastbone. – When young, they are – round and smooth. – As you age, they become – pitted and sharp. – Expert examination can – determine age to within – 1.5 years up to 30, and – within 5 years up to age – 70.

17 Determining Age Bone Density – As you age, your bones lose calcium and become less dense. – X-ray can determine density of calcium. – Malnutrition and disease can lessen bone density at any age.

18 A baby's skeleton has 350 bones, but many of these fuse to give an adult a total of 206 bones. A man's skeleton has broader shoulders than a woman's, a longer ribcage, and a pelvic girdle optimised for walking/running. A woman's skeleton has the same bone complement as a man's but is slightly smaller and less robust, with a wider pelvic opening to assist childbirth.

19 Male and Female Cranium Differences Most important skull differences between men and women are indicated by the letter value on the figure to the left and described below: A) The mans cranial mass is more blocky and massive compared to the females which is rounder and tapers at the top. B) Temporal Ridge - runs along the outer side of the upper skull creating the square shaped of the upper head. More prominent in men than women. C) A woman's supraorbital margin (the ridge above the eyes) is sharper, while the males is rather round and dull. D) The Zygomatic bone (the cheekbone that lies under the lower eye ridge) is more pronounced on the male skull. E) The Mandible (lower jaw) bone of a woman is rounded, while the male's is squared. F) Frontal bone – forehead structure terminates at the brow. The male forehead is lower and more slopping. G) Men have a deeper cranial mass. H) The supercilary arch is large and pronounced in the man. I) A males gonion (most posterior inferior point on angle of mandible) is more flared out and sharply angled. J) The teeth of men tend to be larger.

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21 9. How can ethnic differences be determined from examining skeletal structure? One must look at skull shape including the width of the jaw. People of European ancestor have crowded teeth and a narrow jaw. Those of Chinese origin have wider jaws. North American Aboriginals tend to have larger teeth Hair texture also helps identify Aboriginal, Chinese and Japanese tend to have straight black hair. Even the microscopic shape of the hair varies among different ethnic groups.

22 10. How are dental records used by forensic scientists? Can compare the oral identity of a victim to existing dental record in order to determine identity. 11. What is the biggest problem associated with facial reconstructions? The “superficial touches”, which give the model a lifelike appearance are not very reliable. There is little or no information on the shape or size of the nose or the eyebrows. Likewise with the texture, length, and style of hair.

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30 How an autopsy works 1.The body is received at a medical examiners office or hospital in a body bag or evidence sheet. 2.A brand new body bag is used for each body. This is to ensure that only evidence from that body is contained within the bag.

31 3.The procedure is done with respect and seriousness. The prevailing mood in the autopsy room is curiosity, scientific interest, and pleasure at being able to find the truth and share it. 4.Many autopsy services have a sign, "This is the place where death rejoices to help those who live."

32 6.The pathologist records the results of the external examination and lists all physical characteristics. Height and weight are measured. Skin and hair samples are taken. 6.The examiners tables is fitted with drains for fluid to be washed away

33 8. The body is opened using a Y-Shaped incision from shoulders to mid-chest and down to the pubic region. 9. If the head is to be opened, second incisions are made at the back of the head, joining the prominent bones below the ears.

34 10. There are almost no bleeding because a dead body has no blood pressure. 11. Once the incisions are made, the soft tissues of the chest are reflected back, while the pathologist looks for any abnormalities.

35 12. To enter the chest cavity, the cartilage that connects the ribs to the breastbone must be cut. 13. At the same time, another pathologist is exploring the abdominal cavity. - Starting with the large intestine

36 14. The breast bone is then removed to allow access to the lungs and heart.

37 15. During this dissection, the various organs are examined and weighed and tissue samples are taken. 16. The examiner opens the stomach and examines and weighs the contents. This can sometimes be helpful in figuring out the time of death. 17. Blood samples might be taken to look for bacteria.

38 18. The skull cap is removed using a vibrating electric saw, which cuts through bone, but not soft tissue.

39 19. A series of tests and studies can be performed depending on the situation. 20. When the internal organs, have been examined, the pathologist may return all but the portions they have saved to the body cavity. Or the organs may be cremated without being returned.

40 16.The breastbone and ribs are usually replaced in the body. The skull and trunk incisions are sewed shut ("baseball stitch"). The body is washed and is then ready to go to the funeral director.

41 Other interesting information  A simple autopsy will last roughly two hours. The autopsy of a homicide victim can last from four to six hours.  The tools used to perform autopsies have changed very little in the past 100 years. The only real major advance in tools is the addition of some electrical saws. But even those are still not used as often as the good old-fashioned hand tools.

42 Bone saw - used to cut through bone or skull Breadknife - used to shave slices off of organs for examination Enterotome - special scissors used to open the intestines Hagedorn needle - a heavy needle used to sew up the body after examination Hammer with hook - used to pull skull cap off of skull Rib cutter - special shears used to cut through the ribs Scalpel - like a surgeon's scalpel but with largest blade possible for making long deep cuts or scraping away tissue Scissors - used for opening hollow organs and cutting vessels Skull chisel - used for helping to carefully pry the skull cap off Stryker saw - the electric saw used to cut through the skull to remove the brain Toothed forceps - used to pick up heavy organs - used to shave slices off of organs for examination Enterotome - special scissors used to open the intestines Hagedorn needle - a heavy needle used to sew up the body after examination Hammer with hook - used to pull skull cap off of skull Rib cutter - special shears used to cut through the ribs Scalpel - like a surgeon's scalpel but with largest blade possible for making long deep cuts or scraping away tissue Scissors - used for opening hollow organs and cutting vessels Skull chisel - used for helping to carefully pry the skull cap off Stryker saw - the electric saw used to cut through the skull to remove the brain Toothed forceps - used to pick up heavy organs

43 When asked about the “grizzly” nature of her profession, a pathologist replied as follows: “You've got to be the type of person who can emotionally disconnect [from] it. I mean, if you went into a case looking at it as, 'Geez, this is somebody's little girl or somebody's little boy,' you'd never be able to do the case. You can't personalize it in any way... When you walk in, you never forget that this is somebody's loved one. You never forget that, but when you walk in to do the job, you kinda put that information aside. You look at them more as a puzzle, and your job is to sort out this puzzle. I've got to find out what happened. Who, what, why, when, where. I mean, that's what my job is, to sort out and get those answers. And, do it in a respectful way. A lot of people can't do this type of job. A lot of people don't want to do this type of job. There are a lot of jobs I wouldn't want to do either.”


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