Taphonomy in Forensic Investigations

• Rise in taphonomy in forensic investigations

  •Greater scene attendance

  •More involvement of FA in interpretation of evidence beyond biological parameters

  •Requires an understanding of the roles of other specialists

  •Limited by research focussed on larger time periods e.g. milenia rather than the short term i.e. days, weeks, months, years or decades

  •Some cross over despite time differences
• Biggest difference between Taphonomy and Forensic Taphonomy

  •Related to the time period of interest

  •Short time line

  •Interest in soft tissue decomposition in addition to skeletal

  •Understanding of various processes

  
• Differences between taphonomy and forensic taphonomy

  •Accuracy

  •Taphonomic calculations can be relatively innacurate in archaeology

  •Accuracy is imperative in forensic investigations

  •E.g. Post-Mortem Interval

  •Radiocarbon dating versus Entomology or Hensge’s nomogram

  •Precision

  •Precision in estimations of biological characteristics

  •Age and Stature
• Taphonomic information in forensic investigations

  •Analysis of taphonomy should give us:

  •Scientifically grounded estimates of post-mortem interval based on:

  •Decompositional factors

  •Entomological evidence

  •Biochemical methods

  •Associated physical evidence modification

  •Reconstruction of the original position and orientation of the body

  •Characteristics of the role played by human intervention by excluding those factors attributable to all other agents.

  
• Taphonomic Agents/Factors

  •Hugely complex

  •Numerous factors/agents

  •Interactions between factors/agents

  •The body as an agent

  •Changes over time

  •Variance in effect depending on decompositional state

  •The FA must have an understanding of the sequence of factors and their relationships to each other and the body
• Taphonomic Factors

  •Although complex, factors can be grouped.

  •Environmental Factors

  •Abiotic

  •Biotic

  •Cultural Factors

  •Mortuary activities

  •Cultural modifications

  •Individual factors

  •Those related to the individual themselves

  •E.g. Body Mass

  
• Importance of a taphonomic understanding

  •An understanding of taphonomy allows us to:

  •Estimate post-mortem interval

  •Differentiate between primary and secondary deposition sites

  •Provide a correct interpretation of damage to bone

  •Maximise recovery of remains whether buried or on the surface

  •Explain the position or damage observed as human or non-human intervention

  •Taphonomy has to be interpreted to reveal evidence of forensic importance

  •Taphonomic information can be of forensic significance
• Time periods of interest

  •During the medico-legal investigation, the FA is interested in a number of time periods:

  •Ante-mortem

  •Before death

  •Peri-mortem

  •The period at or around the time of death/deposition

  •Post-mortem

  •From deposition to recovery

  •Post-recovery

  •From recovery to analysis
• Taphonomy

  Presumes an approach which includes:

  •Biological

  •Cultural

  •Environmental influences

  Archaeologists recognised the relationship between understanding taphonomic processes and interpreting human modifications of organic materials
• Haglund and Sorg 1997

  ‘‘use of taphonomic models, approaches, and analysis in forensic contexts to estimate the time since death, reconstruct the circumstances before and after deposition, and discriminate the products of human behaviour from those created by the earth’s biological, physical, chemical, and geological subsystems’’
• Most taphonomic studies have been into events that cover millennia-rather than days, weeks, months, years or decades at the most…However, there are cross over points between the historical and the modern, despite their differences:

  •Determination of factors which cause destruction or damage to bone

  •Understanding how remains can move/change/be altered over time

  •Recognising and understanding human vs non-human causes of bone modification
• Biggest Differences between Historical (traditional) Taphonomy and Modern (forensic) Taphonomy

  Due to the time line-forensic investigation is ALSO interested in soft tissue-

  •Changes,

  •Decomposition,

  •Modification

  •Disarticulation

  •Dispersal

  •Accumulations

  As with any aspect of “forensic” work, forensic taphonomy also requires consideration of accuracy and precision
• Taphonomy should give us

  1. scientifically grounded estimates of postmortem interval (time-since-death), based on decompositional factors (primarily soft tissue, but in later stages may include bone modification factors), entomological evidence, chemical methods, and associated physical evidence modification;

  2) reconstructions of the original position and orientation of the body;

  3) characterizations of the role played by human intervention (as

  a taphonomic agent) on the remains, through the process

  of ‘‘stripping away’’ all other ‘‘natural’’ agents affecting the remains.
• What factors must be considered (not exhaustive)?

  Human Activity:

  •Dispersal

  •Accumulation

  •Treatment of bodyThe Body:

  The Body: The presence of the body affects the surrounding environment

  Environment:

  •Water

  •Marine

  •Fluvial

  •Stagnant

  •Salinity

  •Tidal

  •Land

  •Surface

  •Buried
• What factors must be considered (not exhaustive)?

  Abiotic Factors:

  •Temperature

  •Chemical

  •Coverings inc. clothing

  Biotic Factors:

  •Scavenging

  •Accumulation

  •Dispersal

  •Insect Activity

  •Human intervention