Mummification in a forensic context: an observational study of taphonomic changes and the post-mortem interval in an indoor setting

Abstract

The objective of this study was to evaluate the presence of mummification in an indoor setting, with an emphasis on the forensic perspective. A dataset of 102 forensic autopsy cases was assessed for distribution of desiccation of skin and soft tissue (i.e., subcutaneous fat and musculature) and for moist decompositional (i.e., putrefactive) changes. Further, possible correlation with the post-mortem interval (PMI) was evaluated, as well as the effects of clothing coverage of the body. The results indicated that yellow to orange parchment-like desiccated skin was found at significantly shorter PMIs than reddish brown to black leathery desiccated skin, even when soft tissue desiccation was included in the comparative analysis. Clothing appeared to have a significant decelerating effect on the extent of desiccation on the legs, but findings in regard to whole body or torso/arms were inconclusive. A large variation in PMIs was evident as regards fully desiccated skin (PMI 18-217 days), indicating difficulties in PMI estimation due to a variable repressive effect on the decompositional process per se in an indoor setting. For the specific case in forensic practice, no definite conclusion can be drawn from the observed desiccation changes to the PMI. One way forward might be creating a systematic and standardized method for describing different desiccation types, as well as other cooccurring decompositional changes and how they relate to the PMI, as a foundation for a future quantification model.

Keywords: Desiccation; Forensic taphonomy; Human remains; Mummification; Post-mortem interval estimation.

Fig. 1

Body template used for calculation of body surface affected by desiccation or moist decomposition. Modified after Lund and Browder [31] for assessment of desiccated skin. The anatomical regions (32 in total) were assessed separately and then added together

Fig. 2

Histogram of percentual estimation of body surface in the 102 forensic autopsy cases; a) affected by desiccation, b) affected by moist decomposition, and c) unaffected, grouped by post-mortem interval (PMI). Each of the 48 bars represents one unique PMI value. If multiple cases had the same PMI value, the mean percentual estimation of affected body surface for that PMI was calculated. The x-axis is shown as a categorical scale

Fig. 3

Bar chart showing percentage of cases exhibiting each type of desiccation observed within the dataset. Cases with “leathery desiccation” could host another desiccation process at the same time, but cases with “Exclusively leathery and parchment-like desiccation” did not exhibit any soft tissue desiccation. No cases with only soft tissue desiccation were observed in the dataset

Fig. 4

Distribution of the different desiccation changes expressed as percentages of total number of cases. Ventral and dorsal side combined and represented in one frontal body chart. Details can be found in Fig. S2 to S4

Fig. 5

Scatter plot showing distribution of post-mortem interval (PMI) relative to the type of desiccation the cases exhibited, e.g., “Leathery ± soft tissue desiccation” shows the cases that exhibited leathery desiccation on the body surface, with or without underlying soft tissue desiccation