Taphonomy

Forensic Taphonomy

  • Taphonomy, from the Greek words taphos (burial) and nomos (laws), is the study of the history of a body after death. It focuses on the postmortem environments and interprets the factors that influence the preservation and degradation of human remains.


    Forensic taphonomy is interdisciplinary, drawing on techniques from various fields, including:

  • Biological & Geological sciences

  • Archeology

  • Marine biology

  • Anthropology

  • Entomology

  • Botany

  • Geology

  • Pathology


  • Uses of Forensic Taphonomy:

  • Identification of human remains

  • Determining the cause and manner of death

  • Estimating the postmortem interval (time since death)

  • Locating clandestine graves


    Types of Forensic Taphonomy:

  • Biotaphonomy: Examines the decomposition and destruction of hard and soft tissues. [2]

  • Geotaphonomy: Examines the burial procedure and how the body affects the geological and botanical environment. [2]

Taphonomic Profile

  • A taphonomic profile includes the perimortem and postmortem history, and the circumstances of death.

  • Components of a taphonomic profile:

  • Perimortem and postmortem injuries

  • Time since death (postmortem interval)

  • Assailant, victim, or general mortuary behaviors

  • Location of death

  • Original position of the body and any subsequent movement

  • Forces that caused scattering (human or natural)

  • Predictions of additional or missing remains locations


  • Perimortem Interval: The event of death, and soon after death. Encompasses the events from the time of death to bone exposure through soft tissue loss, body starts to release chemicals. It may be difficult to distinguish perimortem bone injury from antemortem or postmortem injury, as the time since death may overlap with the perimortem period. [4] Bone fracture characteristics can help differentiate:

  • Antemortem: Before death, when the person was alive and how they were healing.

  • Perimortem: Moisture and grease content.

  • Postmortem: Clean, brittle breaks


  • Postmortem Interval: Covers bone modification from the time of soft tissue loss to recovery and curation. Determining a precise postmortem interval is complex and requires substantial information, including:

  • *Temperature - of remains, how surrounding environment changes overtime.

  • Remains

  • Atmospheric conditions

  • Triggering events (e.g., bone weathering due to atmospheric exposure)

Perimortem and Postmortem focuses on:

  • Time between and after death before remains where recovered.

  • The event/circumstances of the death.

Examples of how human remains effect plants, animals and insects:


Factors Affecting Decomposition

  • Biotaphonomy - environmental factors

  • External variables: climate, animals

  • Individual factors: age at death, body size

  • Cultural factors: embalming, autopsy procedures, induced trauma


  • Geotaphonomy - how is the space change due to the dead body.

  • Phenomena of Interest:

  • Soil disturbance

  • Compaction, aeration, mixing of soil layers

  • Tool marks and footprints at the burial site

  • Disrupted plant growth

  • Altered water drainage

  • Changes in soil pH


  • Human Remains and Their Effects on:

  • Water Environments: Decomposition, disarticulation, and movement of remains depend on the water body. Oceanographic models can help determine the origin of the remains.


  • Buried Remains: Grave sites are difficult to locate, and decomposition occurs more slowly due to factors like: [7, 8]

  • Depth of the grave

  • Temperature

  • Soil compaction

  • Fewer scavengers

Role of Other Disciplines

  • Forensic Anthropology:

  • Applies the study of humans to modern legal or public concerns. [9, 10]

  • Focuses on collecting and analyzing human skeletal remains to identify victims and reconstruct events surrounding their deaths. [10]

  • Forensic Odontology: [11]

  • Uses dental remains to identify individuals by comparing them to antemortem or postmortem records. [11]

  • Plays a crucial role in mass disasters or when other identifying features are absent. [11]

  • Forensic Entomology: [12]

  • Studies insects to aid legal investigations. [12]

  • Focuses on insect succession and species found at a crime scene to determine: [13, 14]

  • Timing of events

  • Postmortem interval

  • Cause of death

  • Possible body movement

Postmortem Changes

  • Postmortem Interval (PMI): The estimated time since death. Usually a range of dates/time for example: 2-3 days. The most important factor of determining PMI will always be TEMPERATURE.

    Investigators note factors at the crime scene to estimate PMI, including temperature, clothing or covering, and the presence of: [8, 15]

  • Algor mortis: Cooling of the body. [8]

  • Livor mortis: Blood pooling in the lowest body parts. [15]

  • Rigor mortis: Stiffening of the body. [15]


  • *Stages of Death:

  • Pallor Mortis: Loss of color to the skin. Paleness due to lack of circulation, occurring 15-25 minutes after death and of limited use for PMI estimation. [16]

  • Algor Mortis: The cooling of the body. The body cools at approximately 1 degree Celsius per hour under moderate conditions, though environmental factors and clothing can influence the rate. [16]

  • Rigor Mortis: The stiffening of the body. Muscles contract and joints stiffen 2-5 hours after death, peaking at 12-24 hours and disappearing after 2-3 days. Heat and strenuous activity before death can accelerate rigor mortis.

  • Livor Mortis: The pooling of the blood. Blood settles due to gravity, causing purplish discoloration. It sets in an hour after death, peaks in 3-4 hours, and can indicate if the body has been moved.

    Putrefaction: Skin slippage, skin slips from the bone. Decomposition of proteins, tissues, and liquefaction of organs. [19]

  • Decomposition: Exposure of bones begin.

  • Skeletonization: Completely skeletonized, no tissue. Bones become exposed, soft tissue disappears (3 weeks to years), and bones dissolve from soil acids (20 years at pH less than 7, 100 years at pH 7). [19]


  • *Stages of Decomposition:

    Autolysis

  • Fresh - Soon after death. Chemical breakdown begins, that start to build up.

  • Bloat - The build up of gasses inside remains. Discoloration.(attract flies)

  • Active Decay - Insects begin to open orifices or wounds to decompose remains. (longest stage, maggot activity)

  • Advanced Decay - Exposure of bone, still some soft tissue.

  • Dry/Remains - Fully skeletonized.

Importance of Forensic Pathology

  • Forensic pathologists are medical doctors who study diseases and trauma contributing to death. [20] They conduct autopsies to determine the cause and manner of death, playing a crucial role in investigations. [20, 21]