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 Autopsies Performed by a pathologist ID: 1036347
Download Presentation The PPT/PDF document "Chapter 12: Human Remains" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
1. 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
2. AutopsiesPerformed by a pathologistDetermines the time of death. This can be done most accurately if the body is found within the first 24 hours of deathUses certain indicators such as algor, livor and rigor mortis.
3. Rigor Mortis Temperature Stiffness Approximate Time of body of body Since Death WarmWarmColdColdNot stiffStiffStiffNot stiffNot dead more than 3 hrsDead between 3 and 8 hrsDead 8 to 30 hoursDead more than 30 hoursThe rigidity of skeletal muscles after death.
4. Livor MortisLivor 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 (unable to blanche) between 10 and 15 hours after death.If body is blanchable, it is less than 10-15 hours old
5. Algor MortisAlgor mortis is the cooling rate of the body after death. At a crime scene, the body temperature is obtained through:Liver temperature Glaister equation: 98.4°F - liver temperature/1.5 = hours elapsed since deathGenerally the body cools 1 to ½ degrees Fahrenheit per hour until it reaches the surrounding temperature.Rate of cooling can change depending on the surroundings
6. Insects as EvidenceForensic Entomology
7. Insects as EvidenceForensic entomologists use their knowledge of insects and their life cycles and behaviors to give them clues about a crime. Most insects used in investigations are in two major orders: 1 – Flies 2 – BeetlesBlow FlyCarrion BeetleSpecies succession provide clues for investigators. -Some species may to feed on a fresh corpse, while another species may prefer to feed on one that has been dead for two weeks. -Investigators will also find other insect species that prey on the insects feeding on the corpse.
8. Weather data is also an important tool in analyzing insect evidence from a corpse. Temperature and precipitation levels affect how insects will develop on the bodyOther factors that might affect their estimates:Was the body enclosed in an area or wrapped in a material that would have prevented flies from finding the corpse and laying eggs?Were other insect species present that may have affected the development of the collected species?Were there drugs or other poisons in or on the body that might have affected the larvae’s development?Did you know? Maggots can be used to test a corpse for the presence of poisons or drugs. Some drugs can speed up or slow down the insect’s development. Other Factors to Consider
9. Blow Fly Metamorphosis1st – Adult flies lay eggs on the carcass especially at wound areas or around the openings in the body2nd – Eggs hatch into larva (maggots) in 12-24 hours.3rd– Larvae continue to grow and molt (shed their exoskeletons) as they pass through the various instar stages. 1st Instar - 5 mm long after 1.8 days 2nd Instar - 10 mm long after 2.5 days 3rd Instar – 14-16 mm long after 4-5 days4th – The larvae develop into pupa after burrowing in surrounding soil.5th – Adult flies emerge from pupa cases after 6-8 days.Blow flies are attracted to dead bodies and often arrive within minutes of the death of an animal. It takes approximately 14-16 days from egg to adult depending on the temperatures and humidity levels at the location of the body.AdultEggsPupa3rd Instar Larva2nd Instar Larva1st Instar Larva
10. Examples of BeetlesInformational Source: http://naturalsciences.org/files/documents/csi_tg_overview.doc Images: http://www.cals.ncsu.edu/course/ent425/library/spotid/coleoptera/coleoptera.html & http://www.forensicflies.com/beetles.htmCarrion Beetles (Silphidae)Adults & larvae feed on fly larvaeEarly to Late Stage DecompositionLate Stage DecompositionRove Beetles (Staphylinidae)Predator of fly eggsEarly Stage DecompositionHide Beetles (Scarabidae)Usually the last to arriveClown Beetles (Histeridae)Predator of fly eggsHam & Checkered Beetles (Cleridae)Predator of flies & beetles; also feed on dead tissueSkin Beetles (Dermestidae)Feed on dried skin & tissues
11. Forensic Anthropology in real life 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.”https://www.youtube.com/watch?time_continue=6&v=jiIBpHC7Lfo
12. 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.
13. 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
14. Forensic AnthropologyA 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 rangeSexRaceApproximate heightCause of death, disease, or anomaly
15. OsteologyStudy of bones206 bones in an adult humanFunction of bones:Provides structure and rigidity Protects soft tissue and organsServes as an attachment for musclesProduces blood cellsServes as a storage area for mineralsCan detoxify the body by removing heavy metals and other foreign elements from the blood
16. Age Determination Most accurate estimations from:TeethEpiphyses (bone growth plates)Pubic symphysis (hips)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.
17. Age Determination Using Cranial Sutures Sagittal suture completely closedMales—26 or olderFemale—29 or older Sagittal suture is completely openMale—less than 32Female—less than 35 Complete closure of all three major suturesMale—over 35Female—over 50 Sagittal sutureLambodialCoronal
18. Gender Differences Gender can be determined by examining:Skull FeaturesPubis (hip bones)Relative size of bonesMales are larger than females
19. Gender Differences in Bones The pelvis of the female is wider. Males have a narrow subpubic angle (A) and a narrow pubic body (B).
20. Male Female Sub Pubic Angle
21. Gender Differences The ribcage and shoulders of males are generally wider and larger than that of females.
22. Race CharacteristicsThe skull is particularly useful in determining race if neededRaceNasal PassageOrbital (Eye) SocketsAsiansRoundedRoundedAfricansWideSquareCaucasiansNarrowAngular
23. CAUCASIANAngular Oval OrbitsLong, narrow nasal aperture
24. AsianRounded OrbitsRounded nasal aperture
25. AfricanSquare OrbitsWide Nasal Aperture
26. What differences do you notice between these three skulls? Can you determine race?AsianAfricanCaucasian
27. Estimation of HeightThe height of a person can be calculated by using the length of long bones.Femur, humerus, radius and tibiaBelow 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
28. 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.Used with unidentified remainsHelps give a proportioning of facial features to help in recognition -Does not give a full accurate depiction of the actual appearance of the deceased.
29. Kendall/Hunt Publishing Company29Animal Facial RestorationDetermining what T Rex looked like using the bone formation.From this: To this:
30. Unit 3: BloodTypes/DNA/Spatter
31. SerologySerology is the examination and analysis of body fluids. A forensic serologist may analyze a variety of body fluids including saliva, semen, urine, and blood. With the development of DNA techniques, more time, money, and significance were placed on developing DNA labs. -However, with limited funds and the time required for DNA testing, most labs still use many of the basic serology testing procedures.
32. Blood CharacteristicsPlasma is the fluid portion of the blood (55%)Cells (45%)Erythrocytes are red blood cells. They are responsible for oxygen distribution.Leukocytes are the white blood cells; they are responsible for “cleaning” the system of foreign invaders.Thrombocytes are platelets responsible for blood clotting. Serum is the liquid that separates from the blood when a clot is formed.
33. Animal BloodLarger nucleic red blood cellsFrog bloodHuman versus Animal BloodHuman BloodRed blood cells are most numerous; 5 to 6 million per mm3White blood cells are larger and less numerous; 5,000 to 10,000 per mm3Platelets are tiny, cellular fragments; 350,000 to 500,000 per mm3
34. Blood Types
35. Blood Typing TerminologyABO blood groups—based on having A, B, both, or no antigens on red blood cellsRh factor—may be present on red blood cells; positive if present and negative if notAntigen—a substance that can stimulate the body to make antibodies. Certain antigens (proteins) found in the plasma of the red blood cell’s membrane account for blood type.Antibody—a substance that reacts with an antigenAgglutination—clumping of red blood cells; will result if blood types with different antigens are mixed
36. Blood TypingBlood type A has antigen A on the surface of the cell and will agglutinate with blood type B.Blood type B has antigen B on the surface of the cell and will agglutinate with blood type A.Blood type AB has antigens A and B on the surface of the cells will not agglutinate if type AB receives any other typeWill agglutinate if donated to any other typeBlood type O has neither antigen A nor B will not agglutinate if donated to any typeWill agglutinate if type O receives any other type
37. AgglutinationBlood Clotting due to mixing of blood typesWhy you must be careful when receiving bloodThe picture on the left shows blood agglutination. -Would happen if Type A mixes with Type B -Would happen if any other type is donated to O -Would happen if AB donates to any other typesThe picture on the right shows no signs of agglutination -Would happen if A mixes with A -Would happen if B mixes with B -Would happen if O is donated to anything -Would happen if AB receives anything
38. TypeAntigenAntibodyCan GiveBlood ToCan GetBlood FromABABOABA and BNeitherA nor BBANeitherA nor BA and B A, ABO, AB, ABO, BABA, B, O, ABA, B, O, ABOBlood Types and Donation
39. Population Distribution of Blood Types in the U.S. TypePercentOABAB4540114
40. Rh Factor-Another antigen that can be present + CANNOT donate to – – CAN donate to +
41. Putting it All TogetherO- is the universal donorAB+ is the universal acceptor
42. Genotypes for blood typeALLELECODES FORIAType A BloodIBType B BloodiType O BloodType O is the recessive blood type, which is why it gets a lowercase (i).
43. Genotypes & Phenotypes of BloodGenotypePhenotypeIAIA Type A - HomozygousIAi Type A - HeterozygousIAIB Type AB - HeterozygousIBIB Type B - HomozygousIBi Type B - Heterozygousii Type O – Homozygous recessive
44. Example Problem:Dad is homozygous for Type A blood. Mom is heterozygous for Type B blood. Do a Punnett Square to find out the offspring.IAIBIAiIAIBIAiIAIAIB iChild Genotypes and Phenotypes IAIB Type AB (50%) IAi Type A (50%)
45. DNA Analysis
46. General DNA InformationDouble helix—two coiled DNA strandsIn humans, the order of these bases is 99.9% the same.Four basesAdenineCytosineGuanineThymine
47. DNA Base Pair MatchingBases always pair A to T and G to COriginal DNA Strand: AATCAGTCGComplimentary Strand: TTAGTCAGCYou Try it!Original: TCCGATTCAAGComplimentary Strand: __________________
48. NuclearIn all nucleated cellsInherited 50% from each parentMitochondrialIn all cellsInherited ONLY FROM MOTHERTypes of DNA
49. 49Where Is DNA Found?Nuclear DNA is found in all nucleated body cells—white blood cellsSemenSalivaUrinehair rootTeethBoneTissueCheek cells are the most common site for DNA samplingRed blood cells have no nuclei = no nuclear DNADNA obtained from blood comes from white blood cells
50. DNA Typing DNA typing is a method in which DNA is converted into a series of bands that ultimately distinguish each individual. Only .1% of DNA differs from one person to the next. -Scientists use these regions to generate a DNA profile of an individual.
51. Uses of DNA ProfilingTo identify potential suspectsTo exonerate individualsTo identify crime and casualty victimsTo establish paternityTo match organ donors
52. DNA TYPING “Fingerprinting”PCR—Polymerase Chain Reaction
53. PCR—Polymerase Chain ReactionPCR is a technique used for making copies of a defined segment of a DNA molecule. This can be valuable when the amount of evidence is minimal. Millions of copies of DNA can be made from a single speck of blood.
54. Intro to Gel Electrophoresis
55. ElectrophoresisA technique used to separate DNA fragments.An electrical current is moved through a gel substance causing molecules to sort by size.The smaller, lighter molecules will move the furthest on the gel.
56. ElectrophoresisStep 1: Pipette the DNA. Step 2: Load DNA into the gel wells.Step 3: Run the gel. Step 4: Observe and compare bands of DNA.
57. Three Possible OutcomesMatch—The DNA profile appears the same. Lab will determine the frequency.Exclusion—The comparison shows profile differences that can only be explained by the two samples originating from different sources.Inconclusive—The data does not support a conclusion as to whether the profiles match.
58. Reading Results Practice
59. Who Should be arrested?
60. FBI’s CODIS DNA DatabaseCombined DNA Index SystemUsed for linking serial crimes and unsolved cases with repeat offendersLaunched October 1998Links all 50 states
61. Blood Spatter Analysis
62. Blood Spatter EvidenceA field of forensic investigation that deals with:Physical properties of blood Patterns produced under different conditions as a result of various forces being applied to the blood. Considered circumstantial and class evidenceBlood, as a fluid, follows the laws of physics.
63. Blood Droplet CharacteristicsA blood droplet remains spherical in space until it collides with a surface.Once a blood droplet impacts a surface, a bloodstain is formed.Droplets falling from the same height, hitting the same surface at the same angle, will produce stains with the same basic shape.
64. Questions Answered by Blood Spatter InterpretationThe distance between the target surface and the origin of the bloodThe point(s) of origin of the bloodMovement and direction of a person or an objectThe number of blows causing the bloodshed Type and direction of impact The position of the victim and/or object during bloodshedMovement of the victim and/or object after bloodshed
65. Conditions Affecting Shape of Blood DropletDirectionAngle of impactVelocity at which the blood droplet left its originHeight from where blood dropped
66.
67. Blood Stain Patterns-Velocity
68. Bloodstain Patterns-DirectionThe pointed end of the bloodstain faces the direction of travel.If there is more than one drop, you can determine point of origin (where direction lines intersect)
69. Higher drop point = larger spatterDiameter increasesBloodstain Patterns-Height
70. Bloodstain Patterns-Angle of ImpactThe shape of a blood drop:Round—if it falls straight down at a 90-degree angleElliptical—blood droplets elongate as the angle decreases from 90 to 0 degrees; the angle can be determined by the following formula: WidthLength
71. The more acute the angle of impact, the more elongated the stain.90-degree angles are perfectly round drops80-degree angles take on a more elliptical shape.At about 30 degrees and below the stain will begin to produce a tail.Bloodstain Patterns-Angle of Impact
72. Bloodstain Patterns-Angle of ImpactPRACTICE 1) Measure width and length 2) Divide the length by the width 3) take the sin-1 of that numberTry with the above blood drops to see if your work matches the actual angle of impact WidthLength