The Cake Theft Mystery and Forensic Taphonomy

1. Warm-Up • During a recent police investigation, Chief Inspector Stone was interviewing five local villains to try and identify who stole Mrs Archer's cake from the mid-summer fair. Below is a summary of their statements: Arnold:  it wasn't Edward         it was BrianBrian:   it wasn't Charlie         it wasn't EdwardCharlie: it was Edward         it wasn't ArnoldDerek:   it was Charlie         it was BrianEdward:  it was Derek         it wasn't Arnold • It was well known that each suspect told exactly one lie. Can you determine who stole the cake?

2. Forensic Taphonomy

3. Forensic Taphonomy • Forensic taphonomy is the study of the history of the body since death. • Taphonomy is derived from Greek taphos (burial) and nomos (laws). • Taphonomy is important because it may assist in; • Estimating the time since death by observing postmortem changes • Identification of the individual • Ability to determine cause and manner of death

4. Categories of Trauma • Mechanical – sharp or blunt • Thermal – hyperthermia or hypothermia • Chemical – drgus or poisins, CO kills by asphxyation • Electrical – causes ventricular fibrilation • Asphyxial – low Oxygen

5. Eccymosis Ligature Marks Petechia

6. Mechanical Sharp Blunt • Knives, Swords, Axes • Firearms • Handgun • Shotgun • Nonfirearms

7. Blunt force Hesitation

8. Double edge Slash wound Single edge

9. Entrance wounds • Close • Contact wound – skin blackens • Red discoloration due to released CO (few inches) • Larger lacerations on head wounds • Intermediate • Less gas effects • Stippling/tattooing from unburned powder • Distance • Circular defect • Abraded rim on skin

10. Contact Wound Shotgun Close Intermediate Close Handgun

11. Distance wound Intermediate – Stippling/tattooing

12. Exit Wounds • Not always larger • Small slit shaped • Slow speed - few side lacerations • High speed – many side lacerations “bunny ears” • Shored exit – due to clothes, easily confused with distance entrance but abrasions are wider than entrance

13. With lacerations Shored exit versus entrance wound Without lacerations

14. Trauma Terms to Know • Hematoma – “goose eggs”, tumor of blood • Contusion – leaves patten of weapon when blood leaks out of cells • Laceration – blunt force wound • Incised wound – sharp force wound • Stab – longer length than width wound • Exsanguination- bleed out • Perforating – gun wound with entrance and exit • Penetrating – gun wound with no exit

15. What is Forensic Taphonomy • Taphonomy is the study of the processes that affect the decomposition, dispersal, erosion, burial, and re-exposure of organisms after, at, and even before death. • Forensic Taphonomy is a subfield of forensic anthropology.

16. Biotaphonomy • Biotaphonomy examines the remains themselves and asks how decomposition and destruction of the hard and soft tissue was brought about. • Biotaphonomic variables can be subdivided • Environmental factors • Individual factors • Cultural factors

17. Geotaphonomy • Geotaphonomy is the study of how someone who buries a body, and how the body itself affects the surrounding geological and botanical environment.

18. Contributions of Methods and Theory • Forensic taphonomy requires interdisciplinary input from biologists, archeologists, anthropologists, entomologists, botanists and geologists, among others. • Forensic anthropologists are primary facilitators of taphonomy into forensics

19. Contributions of Methods and Theory • Archaeological techniques of recognition, search, recovery, and documentation of findings are critical in taphonomy • Other techniques, such as 3-D mapping, stratigraphy, botanical and entomological collection, conservation, and exhumation are used.

20. Taphonomic Factors • Forensic Taphonomic history includes: • Actual death • Interval of bone exposure through soft tissue modification • Potential interval of bone modification • Point of discovery and collection

21. Taphonomic Factors • Of particular interest in medicolegal death investigation is: • Perimortem interval, • Boundary between soft tissue modification and bone exposure, • Interval in which bone is exposed to modifying agents (weather, water, soil, animals, etc)

22. Taphonomic Factors • Perimortem interval- discriminating antimortem from postmortem injuries to bone is difficult • Antimortem/Perimortem injuries include ability to define moisture and grease content of bone, i.e.; greenstick, or spiral fractures • Postmortem fractures include clean brittle breaks, parallel or cross fracture of long axis of bones • Moisture loss occurs over time

23. Taphonomic Factors • Several factors affect estimates of postmortem interval: • Determining triggering event • Cultural factors • Environmental factors • Carcass temperature and loss of blood • Atmospheric conditions • Location of deposition of body – water, underground, on top of ground

24. Taphonomic Factors • Animals and human remains • Most commonly found scavengers of human remains are: • Carnivores • Rodents • Insects • Microbes

25. Taphonomic Factors • Dogs and rodents are primary scavengers of remains • Dogs and cats leave v-shaped defects in soft tissue • Clawing, digging or tugging at remains can also alter appearance • Rodents leave tightly circumscribed and even margins, dual teeth marks • Scavengers also leave behind hair, tracks and feces

26. Taphonomic Factors • Plants and human remains: • Seasonal shedding of leaves or needles can cover remains • Roots can cause mechanical damage • Fungi can secrete acid • Microenvironmental changes can be caused by rootlet proximity to bones and subsequent moisture conservation and microbial activity

27. Human Remains in Water Environments • Water presents a myriad of problems with death investigations: • Type of water body (ocean, river, lake) • Disarticulation in water and problems with original location of water • Temperature, depth, and current of water all affect body decomposition, as does seasonal weather

28. Buried Remains • Major problem by burial is locating grave • Methods to determine grave location include: • Witness statements • Visual clues • Cadaver dogs • Trenching and probing • Area photography • Remote sensing

29. Buried Remains • Buried bodies normally decompose slower than bodies on surface due to: • Less exposure to scavengers and insects • Temperature fluctuates less the deeper the body is in grave • Less exposure to weather • Compaction of soil • Differences in pH due to decaying matter • Moisture level

30. The Body FarmThe research farm, known as The Body Farm, was established in 1981 by Bill Bass, a professor of forensic anthropology. http://video.nationalgeographic.com/video/player/science/health-human-body-sci/human-body/body-farm-sci.html

31. THE BODY FARM • PRIMARYGOAL: To understand the processes & timetable of postmortem decay, primarily to improve determining the "timesincedeath” • The Body Farm is a simulation of various crime scenes using real human bodies. • Started in 1970-80’s to study ForensicAnthropology (the study of human decomposition after death).

32. THE BODY FARM • Used by Law Enforcement, Medical Examiners, Entomologists, Cadaver Dogs, Anthropologists & FBI for Crime Scene Training. • The BF uses unclaimed cadavers & volunteers (who donate their body to science after death) • Only 2 Facilities in the U.S. • Univ. of Tennessee (original) • Western Carolina University • Texas State University • Sam Houston State University

33. Types of Research How does the decomp rate compare in: • sunshine vs shade? • In cool weather vs hot weather? • In a shallow grave vs on the ground? • In water? • Inside a car? • What effect do other variables have—humidity, insect activity, clothing, body weight, and so on?

34. Why is TSD so important? • 1st question at most murder scenes: "How long has this person been dead?“ • It's crucial to know when the crime was committed. • it can help narrow the search for a suspect or • it can help rule out potential suspects who had alibis at the time the victim was killed.