One of the trickier components of a forensic anthropologists’ job is to provide an estimate of the postmortem interval (PMI), which reflects the amount of time between an individual’s death and the discovery of their remains. For example, when investigating unidentified human remains, PMI estimates can be key for finding potential matches from missing persons lists. Even in the courtroom, a PMI serves as crucial evidence in affirming or contradicting a suspect’s alibi.
One of the most widely used methods for estimating PMI in forensic anthropology was published by Megyesi and colleagues in 2005. This method scores the condition of the remains on various anatomical-specific scales based on the extent of decomposition, resulting in an equation for calculating the accumulated degree days (ADD) necessary for this amount of decomposition to have occurred. ADD is then be compared with local weather data to provide a PMI to investigators. However, a recent validation study has found this equation to be inaccurate and unpredictable. Although other approaches to PMI estimation exist, the accuracy of PMI estimation appears to vary based on the environment, the method utilized, and the experience of the observer.
Oostra and colleagues recently unveiled a new human taphonomic research facility in Amsterdam that hopes to address such issues (Figure 1). This facility, called the Amsterdam Research Initiative for Sub-surface Taphonomy and Anthropology (ARISTA), is the first of its kind in Europe and paves the way for future centers of international research. Taphonomy encompasses an area of paleontology that studies the way things decay or fossilize, but in a forensic context refers to the study of factors that affect the body between death and recovery. The existence of ARISTA is directly tied to the multiple Dutch University body donation programs. Oostra et al. point out in their article that the Dutch Burial and Cremation Act legally includes body donation as 1 of 3 final dispositions for human remains, alongside burial and cremation. Prior to ARISTA, scientific body donation meant consenting for dissection at a medical school, where body donations provide important experience and anatomical knowledge for medical students. However, in 2013, multiple Dutch governmental departments agreed that, with donor consent and ethical guidelines in place, scientific body donation for decomposition research was allowed.
Before human taphonomic research facilities, animal remains were commonly used as a substitute for human remains in decomposition studies. However there are critical differences between human and non-human organisms’ decomposition rates. As Oostra and colleagues note, the profiles of volatile organic compounds, or chemicals that naturally vaporize into a gas, that are released during decomposition differ between species. Also, individual circumstances surrounding medical history, intoxication, and other personal variables may change decomposition patterns. Even body size may impact decomposition rates! Oostra and colleagues highlight the great number of possible interactions that occur between biological, geological, hydrological, and other factors throughout decomposition that can create case-specific decomposition patterns. In short, the use of human, not animal, remains for decomposition research is paramount if practitioners hope to increase the precision of current PMI estimation methods.
Although the ARISTA is the first of its kind in Europe, this facility follows in the footsteps of multiple human decomposition research facilities within the United States and across the globe. These so-called “body farms” have famously studied forensic taphonomy for years throughout the United States. Of these, the 26-acre Forensic Anthropology Research Facility (FARF) at the Forensic Anthropology Center at Texas State in San Marcos, Texas is currently the largest in the world (Figure 2). Similar to ARISTA, FARF functions with the help of the Texas State University Willed Body Donation Program. However, while donors at the ARISTA are exclusively buried in shallow graves, the size of FARF means that donors can be placed in a variety of situations, where they are photographed and observed by anthropology students. Donors may be buried, placed under animal-scavenger-proof barriers, or uncovered for scavenger-specific research.
For example, research at FARF has used motion sensing cameras to observe and better understand the effects of vulture scavenging on human remains. Undergraduate and graduate students at Texas State University volunteer with the Body Donation Program, through which they assist with ongoing decomposition research, clean skeletal remains in wet laboratories, and curate skeletal remains for further research. In addition, the Forensic Anthropology Center at Texas State provides realistic, hands-on courses for forensic investigators. Thus, willed body donors at FARF effectively help train the next generations of forensic anthropologists while continuing to educate working professionals.
The first inhumation took place at the ARISTA in March of 2018, and the facility officially opened in November of the same year. Oostra and colleagues’ publication on the logistics and benefits of a human decomposition facility aims to set the precedent in Europe for similar initiatives. Although a well-established practice in the United States, the addition of more research facilities will improve current PMI studies and methods. Human taphonomic research facilities are critical resources for forensic scientists that are made possible through the generosity of willed body donors. They act as incredible bridges for the dead to give back to the living, and for the living to learn from, and ultimately better serve, the dead.
|Title||Amsterdam Research Initiative for Sub-surface Taphonomy and Anthropology (ARISTA) – A taphonomic research facility in the Netherlands for the study of human remains|
|Authors||Roelof-Jan Oostra, Tamara Gelderman, W.J. Mike Groen, H. Gepke Uiterdijk, Erik L.H. Cammeraat, Tristan Krap, Leah S. Wilk, Mark Lüschen, W. Elly Morriën, Frans Wobben, Wilma L.J.M. Duijst, Maurice C.G. Aalders|
|Journal||Forensic Science International|
|Citation||R-J Oostra; T Gelderman; WJM Groen; HG Uiterdijk; ELH Cammeraat; T Krap; LS Wilk; M Lüschen; WE Morriën; F Wobben; WLJM Duijst; MCG Aalders; Amsterdam Research Initiative for Sub-surface Taphonomy and Anthropology (ARISTA) – A taphonomic research facility in the Netherlands for the study of human remains. Forensic Science International, 2020, 317. DOI: 10.1016/j/forsciint.2020.110483|