Forensic Pathology

1. Forensic Pathology Ms. Faulconer and Dr. Walker

2. Terminology Write bold ! • Autopsy – The postmortem evaluation of a human body • Postmortem – “after death” • “Autos” – self, “Optos” – seen (Greek) • Necropsy – The postmortem evaluation of an animal • “nekros”- corpse (Greek)

3. Pathology Write all ! • Field of medicine related to diagnosis of disease • Forensic pathology - Focuses on determining the cause of death by examining a corpse • Requires an M. D. degree plus residency in pathology (total time after high school > 12 years) • Most pathologists do not see patients (at least not live ones)

4. What makes a good pathologist? • A talent for and interest in science. This should include not only biology, but physics, chemistry, and the social sciences (anthropology and psychology). For the bread-and-butter technical part of your work, you should especially have a good grasp of spatial relationships. (geometry, anyone?) • Good communication skills. You will not only be interacting with law officers, but you'll be trying to convince judges and juries that your findings are valid. • Strong stomach. You'll be routinely dealing with dismembered and/or rotting bodies. From a pure visceral standpoint there is no job more disgusting than forensic pathology.

5. What makes a good pathologist? • Thick skin. You will be periodically raked over the coals by the local media, who apparently cannot to resist the urge to armchair-quarterback your work. You will also make many enemies among the citizenry. For instance, when you determine that Daddy killed himself, and he wasn't poisoned by that blond bimbo who was only interested in his money, you are going to have some very angry children buzzing around you. • The mind of a detective. You will have to constantly be on guard against being fooled by malefactors smarter and more focused than you. You will have to have some insight into the heart and mind of a criminal.

6. Autopsy Write all ! • Internal and External Examination of the body after death • Document disease/injuries • Determine time since death (PMI) • Determine cause/manner of death • Cause: specific reason person died (e.g. gunshot wound to the head) • Manner: Categories (homicide, accident, suicide, natural, undetermined)

7. Autopsy Write all ! • Internal and External Examination of the body after death • Determine mechanism of death • Physiological reason for death (shock, blood loss, asphyxia) • Establish identity

8. Steps Write all ! • 1st - External Examination • height/weight • Photography • UV exam (fluids) • 2nd - Toxicology • Nail scrapings • Fluid samples • Analysis (GC/MS) • 3rd - Internal Examination • Head (circular saw) • Chest (Y incision) • Abdomen * Inspect organs and weigh

9. Steps of an Autopsy • First step: Examination of the exterior of the body • Records are made of height, weight, and any visible characteristics • Photographs are taken from every possible angle and the body is examined by UV light (find UV active fluids)

10. Steps of an Autopsy • Second step • Blood, hair, urine, and oral swab samples are taken • Nail scrapings are collected and the body is X-rayed • Samples may be analyzed by GC-MS (toxicology screening)

11. Steps of an Autopsy • Third Step • The pathologist makes a Y incision with a scapel; from each shoulder to midchest, then from midchest to pelvis. • An incision is made across the skull from ear to ear. The skin is pulled back and the bone is cut with a vibrating saw.

12. Steps of an Autopsy • Third Step • The brain and major organs (heart, liver, kidneys, spleen) are removed, weighed, tissue samples taken and analyzed. • Stomach contents may be analyzed if present. • The neck and windpipe are examined for abnormalities. • After the examination, the organs are put back in the body and the body is sewn back together (for burial).

16. Macroscopic Analysis Write all ! • CO poisoning • Cherry red coloring • Defense Wounds • Wounds on palms from holding up hands when attacked

17. Macroscopic Analysis Write all ! • Organs • Polycystic kidneys (top right) • Tuberculosis (lungs) (low right) • Stroke aka infarction (below)

18. Microscopic Analysis Write bold ! • Fat Embolism • Long bone trauma • Burns • Severe soft tissue trauma • Shaken Baby Synd. • Torn axons

19. PMI Write all ! • Post-Mortem Interval • The time elapsed since death • Can be determine scientifically & non-scientifically • Traditional Methods: • Algor Mortis • Livor Mortis • Rigor Mortis • Nontraditional methods: • Entomology

20. Algor Mortis Write all ! • Cooling of the body • Body temperature = 37 Celsius (98.6 Farenheit) • Basic Formula for Time of Death: • Body cools one degree/hour after death • 37 – Body Temperature Postmortem = Hours after death • Temperature measured by liver or rectum

21. Write all ! Factors Affecting Algor Mortis • Indoors/Outdoors • Clothing or lack thereof • Multiple layers slow cooling • If naked, cooling is faster • If outdoors • Weather conditions • Cold, wind, moisture accelerate body cooling

22. Livor Mortis Write all ! • Discoloration due to blood settling • Lividity= degree of discoloration

23. Livor Mortis Write bold ! • Once the heart stops pumping blood will pool in the area of the body closest to the ground. • Begins to appear 6-10 hours after death and is fixed after 24 hours • May not be fixed if the body is moved within the first 12 hours after death • A forensic pathologist can use this information to determine whether the body has been moved and to get some idea of TOD.

24. Rigor Mortis Write bold ! • Stiffening of the muscles of the body. • Occurs due to buildup of lactic acid in the muscles postmortem, inability of muscles to pump calcium out of the cell • Rigor starts in the small muscles of the face and progresses to the neck , upper extremities, trunk and lower extremities

25. Rigor Mortis Write all ! • Rigor Mortis is usually complete after 36 hours and muscles permanently relax • Rigor mortis is unreliable by itself • Affected by • Drug use • Exertion prior to death

26. Write all ! Petechial Hemmhoraging • Pinpoint red mark that is a sign of manual strangulation, hanging, or smothering • Occurs when blood leaks from capillaries in eyes • Occurs in eyes and on eyelids

28. Forensic Entomology Write all ! • Typically requires a Ph. D. in Entomology, followed by additional training in forensic applications.

29. Circle Of Life… Write all ! • Bacteria colonize corpses first • Tolerant of acidic conditions postmortem • Already present in body before death • Activity neutralizes tissues

30. Circle Of Life Write bold ! • Flies show up next • Bacterial activity neutralizes and moistens flesh, which can then be eaten by flies • Flies lay eggs, life cycles continue until moist flesh is consumed

31. Circle of Life Write all ! • Beetles/Mites • Some species eat fly larvae, so they’ll show up where the flies are • Can consume drier flesh • Hide beetles – can consume keratin, present in hair and nails

32. Circle Of Life Write all ! • Wasps • Lay eggs inside and eat fly pupae

33. What can bugs tell us? Write bold ! • Urban species in a rural environment or vice versa can indicate that the body has been moved from one setting to another. • Skuttle flies – reproduce underground • Blow flies – reproduce above ground • The presence of Skuttle fly larva on a body found on the surface may indicate a previous burial. Likewise blowfly larvae on a buried body may indicate burial after some time on the surface.

34. What can bugs tell us? Write all ! • Lack of insect activity can indicate storage at freezing temperatures or enclosure in an air tight container • Sealing a body in a plastic garbage bag, a vehicle, a rug and/or burning it does not deter colonization

35. Forensic Anthropology http://library.thinkquest.org/04oct/00206/images/5_60_skull.JPG

36. Anthropology Write bold • The study of humans and it consists of several sub-fields:  • Physical anthropology — the study of the primate order, past and present, such as primate biology, skeletal biology, and human adaptation • Cultural and linguistic anthropology — the study of the aspects of human society and language, past and present • Archaeology — the study of past cultures via material remains and artifacts

37. Write bold Forensic Anthropology • Draws predominantly from the field of physical anthropology • Osteology – the study of bones • Most are Ph. D’s who work primarily as professors • “In those cases in which soft tissue has been degraded by time, temperature, environment or other external forces, the only tissue remaining more or less intact is bone.”  http://www.trutv.com/library/crime/criminal_mind/forensics/anthropology/1.html

38. Forensic Anthropologist Write all ! • Called into a crime scene when: • Remains are found during archeological excavation • Remains are badly burned or decomposed • Skeletonized remains are found

39. Identifying Factors Write all ! • Provide law enforcement with a biological profile of the deceased • Age • Sex • Ancestry • Stature (Height, body type) • Previous trauma (injuries) • Potential Cause of Death • This helps narrow down the possible identity of the decedent.

40. Write all ! Age Determination • Older adults can have the following: • Calcium and other mineral deposits • Changes in the pelvis or evidence of bone diseases like arthritis • Bones become less dense with age • Other clues come from the developmental stages in the teeth and from worn areas in enamel.

41. Write all ! Age Determination • Looking at the teeth can reveal the age if the remains belong to a child or adolescent. • Human teeth break through in a predictable pattern and offer a fairly reliable estimate between five months and 21 years. • Baby teeth (20) vs. permanent teeth (32) • Presence or absence of wisdom teeth (usually > 15 y.o.)

43. Age Determination Write all ! • The young • The epiphyseal union -- areas of the femur that gradually fuse as a person ages -- can help estimate young ages if the teeth are missing.

44. Physical Characteristics Write all ! • Height Determination • Rule of thumb: Height = 5 x Humerus length • Formulas for height based on other major bones as well (spine, tibia, and femur).

45. Ethnicity Write all ! • Ethnicity can be determined from variations in the facial structure, especially the nose and eye sockets.  • In people of African and Asian descent, the nose ridge is broader than in Caucasians. http://www.internetlooks.com/nasalbonecharacteristicstypical.jpg

47. Physical Characteristics Write all ! • Gender Determination: Pelvis • Female pelvic girdle is wider than a man’s. Female pelvis Male pelvis

48. What can they figure out? Write all ! • In skeletal trauma analysis, some forensic anthropologists can accurately determine: • Degree of force (sharp, blunt, ballistic) • Cuts from a knife • Bullet holes • Fracture from blunt object • Evidence of poisoning • When the blow occurred (before, near, or after T.O.D.)

49. Write all ! Determining Postmortem Interval • Postmortem Interval – Determining time since death • As bodies decompose, they leak five fatty acids -- the breakdown products of muscle and fat -- into the ground. • Concentration and identity of acids • Can reveal time since death • Can reveal how long the body has been in a location

50. Determining Postmortem Interval • The first technique traces the ratio of the five fatty acids in comparison to each other -- a method that works as long as there is soft tissue (skin and organs) on the body. • If not, another technique tracks the ratios of seven inorganic compounds, such as sodium and calcium, which leach into the soil from the bones. • If a body is too badly decomposed for those techniques, scientists rely mostly on bones.