Semester of Graduation
Spring 2019
Degree
Master of Arts (MA)
Department
Geography and Anthropology
Document Type
Thesis
Abstract
Forensic anthropologists are often called upon to assess the postmortem interval (PMI; i.e. time since death) of remains in varying states of decomposition and skeletonization. These assessments rely on familiarity with general taphonomic sequences and processes, in addition to experience with how these processes present in local environments and conditions. Assessment using such qualitative methods is a subjective process. Therefore, some researchers have developed formulae whose purpose is to estimate PMI in an objective format. In these instances, the resultant PMI estimation formulae were developed using local data and therefore have the potential for local applicability. Additionally, for some regions, data on local processes are available from studies conducted at outdoor decomposition research facilities. The goal of this study was to examine the application of previously collected taphonomic data on individuals in Louisiana through a retrospective analysis of forensic casework. Furthermore, this study will serve as a method validation of the Total Body Score (Megyesi et al., 2005) and Vass (2011) PMI estimation formulae when applied in southern Louisiana. The hypothesis evaluated in this study was that unique patterns of taphonomic sequences and processes would be observed, even though Louisiana shares a climatic zone with three existing decomposition research facilities. The study sample was selected from the case files of the Louisiana State University Forensic Anthropology and Computer Enhancement Services (LSU FACES) Laboratory. Only individuals with both PMI estimates and independently known actual PMIs were considered (n=79). Results show that actual PMI fell within the range of the estimated PMI for 69 of the 79 cases (87%). Of the 10 that did not, nine cases underestimated actual PMI and one case overestimated PMI. Depositional environment and other variables were further examined to assess relationships between the state of decomposition, actual PMI, and estimated PMI. That is, the sample was separately divided by stage of decomposition, depositional context, presence or absence of clothing, scavenging, and trauma, season, and year of analysis. Regarding the PMI estimation formulae, the equations had differing degrees of success when applied in Louisiana. The diversity in decomposition stages in varying situations and the conditional success of the PMI estimation formulae support the need for further research regarding the characterization of decomposition in Louisiana. The further study of decomposition in Louisiana could be achieved with the development of an outdoor decomposition research facility in this state.
Recommended Citation
Reck, Sophia, "A Retrospective Analysis and Method Validation of Postmortem Interval Estimation in Louisiana" (2019). LSU Master's Theses. 4878.
https://repository.lsu.edu/gradschool_theses/4878
Committee Chair
Ginesse Listi
DOI
10.31390/gradschool_theses.4878