Evaluating the utility of time-lapse imaging in the estimation of post-mortem interval: An Australian case study

Alyson Wilson; Stanley Serafin; Dilan Seckiner; Rachel Berry; Xanthé Mallett

doi:10.1016/j.fsisyn.2019.08.003

Evaluating the utility of time-lapse imaging in the estimation of post-mortem interval: An Australian case study

Forensic Sci Int Synerg. 2019 Aug 17:1:204-210. doi: 10.1016/j.fsisyn.2019.08.003. eCollection 2019.

Authors

Alyson Wilson¹, Stanley Serafin², Dilan Seckiner³, Rachel Berry⁴, Xanthé Mallett^{5

6}

Affiliations

¹ School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Queensland, 4700, Australia.
² School of Medical Sciences, University of New South Wales, Sydney, New South Wales, 2052, Australia.
³ Centre for Forensic Science, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia.
⁴ School of Community Health, Charles Sturt University, Port Macquarie, New South Wales, 2444, Australia.
⁵ School of Humanities and Social Science, University of Newcastle, Callaghan, New South Wales, 2308, Australia.
⁶ Honorary Associate in Centre for Forensic Science, University of Technology, Sydney, Australia.

Abstract

Estimating post-mortem interval is an important aspect in forensic investigations. The aim of this study was to investigate if time-lapse imaging can be used to improve estimates of post-mortem interval using Megyesi et al.'s [1] method for a human donor decomposing in an Australian environment. To achieve this, time-lapse images were taken every 30 min over a 6-month period. The Megyesi et al. [1] total body score (TBS) system was used to quantify the level of decomposition of the donor for each image. Linear regression was performed to determine if observing decomposition more than once a day leads to increased accuracy in predicting PMI (post-mortem interval). Decomposition initially progressed quickly and then plateaued at 1004 hours PMI, with a TBS of 24. Individual timestamps were created from the time-lapse images taken each day at 08:00 hrs, 11:00 hrs, 14:00 hrs, 15:00 hrs, and 17:00 hrs. All timestamps produced R² values > 0.80, indicating that the Megyesi et al. [1] method accurately predicts PMI for this donor. The 08:00 hrs timestamp had the highest value R² = 0.886, whilst the combined timestamp (which included the scores from all five images for each 24-hour period) R² = 0.823 was the lowest. This study supports the validity of Megyesi et al.'s [1] TBS model to estimate PMI. Two other interesting findings were that the results suggest that scoring TBS multiple times per day does not improve estimates of PMI, however scoring TBS at daybreak produces more accurate results than scoring TBS later in the day. This may be an important consideration in forensic scenarios.

Keywords: Australian facility for taphonomic experimental research; Forensic anthropology; Taphonomy; Time-death interval.