Forensic Taphonomy

1
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

2
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

3
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.

4
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

5
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)

6
Taphonomic Factors

• Perimortem interval- discriminating antemortem
  from postmortem injuries to bone is difficult
• Antemortem 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

7
Taphonomic Factors

• Postmortem Interval
• Estimating can be as imprecise as estimates of
  perimortem interval
• Observations from death to recovery must be
  specified
• Certain processes lend themselves to
  partitioning, including decomposition, carnivore
  disarticulation, and weathering

8
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

9
Taphonomic Factors

• Animals and human remains
• Most commonly found scavengers of human remains
  are
• Carnivores
• Rodents
• Insects
• Microbes

10
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
• Scavengers also leave behind hair, tracks and
  feces

11
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

12
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

13
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

14
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