Histological quantification of decomposed human livers: a potential aid for estimation of the post-mortem interval?

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ORIGINAL ARTICLE

Histological quantification of decomposed human livers: a potential aid for estimation of the post-mortem interval? Ann-Sofie Ceciliason 1

&

M. Gunnar Andersson 2

&

Sofia Nyberg 3 & Håkan Sandler 1,3

Received: 2 June 2020 / Accepted: 12 November 2020 # The Author(s) 2020

Abstract The objective of this study was to determine if a novel scoring-based model for histological quantification of decomposed human livers could improve the precision of post-mortem interval (PMI) estimation for bodies from an indoor setting. The hepatic decomposition score (HDS) system created consists of five liver scores (HDS markers): cell nuclei and cell structure of hepatocytes, bile ducts, portal triad, and architecture. A total of 236 forensic autopsy cases were divided into a training dataset (n = 158) and a validation dataset (n = 78). All cases were also scored using the total body score (TBS) method. We specified a stochastic relationship between the log-transformed accumulated degree-days (log10ADD) and the taphonomic findings, using a multivariate regression model to compute the likelihood function. Three models were applied, based on (i) five HDS markers, (ii) three partial body scores (head, trunk, limbs), or (iii) a combination of the two. The predicted log10ADD was compared with the true log10ADD for each case. The fitted models performed equally well in the training dataset and the validation dataset. The model comprising both scoring methods had somewhat better precision than either method separately. Our results indicated that the HDS system was statistically robust. Combining the HDS markers with the partial body scores resulted in a better representation of the decomposition process and might improve PMI estimation of decomposed human remains. Keywords Forensic taphonomy . Post-mortem interval estimation . Hepatic decomposition score . Total body score

Introduction Estimation of the post-mortem interval (PMI) is one of the most complicated tasks in forensic practice. A more reliable PMI estimate would be of great value in forensic investigations, where it could for instance help to elucidate the course of events, as well as to evaluate suspects’ alibis based on their whereabouts during the timespan of a suspected crime. Consequently, there is a constant desire to identify good predictors of the PMI that would yield a more accurate estimate or at least assign a narrower time interval. In decomposed * Ann-Sofie Ceciliason [email protected] 1

Forensic Medicine, Department of Surgical Sciences, Uppsala University Hospital, Uppsala University, SE-751 85 Uppsala, Sweden

2

Department of Chemistry, Environment and Feed Hygiene, The National Veterinary Institute, SE-751 89 Uppsala, Sweden

3

Department of Forensic Medicine, The National Board of Forensic Medicine, Box 1024, SE-751 40 Uppsala, Sweden

human remains, the PMI is especially difficult to estimate with certainty due to the complexity of the decomposition process. The indoor decomposition of human remains has not been studie