Journal of Forensic Sciences - 2021 - Alfsdotter - Outdoor human decomposition in Sweden A retrospective quantitative

Study Overview

  • Title: Outdoor human decomposition in Sweden: A retrospective quantitative study of forensic-taphonomic changes and postmortem interval in terrestrial and aquatic settings.

  • Authors: Clara Alfsdotter, Anja Petaros

  • **Key Findings: **

    • Analyzed 94 cases: 43 terrestrial, 51 aquatic.

    • Median postmortem interval (PMI) = 48 days.

    • Significant differences in decomposition patterns observed between terrestrial and aquatic environments.

    • Terrestrial decomposition:

      • Includes partial saponification/desiccation; complete skeletonization occurring after 2+ years.

    • Aquatic decomposition:

      • Slower due to extensive saponification, especially post 1-year PMI.

Key Findings

  • Accumulated Degree-Days (ADD):

    • Universal equations for estimating ADD showed poor performance.

    • 80% variance in terrestrial decomposition can be explained by ADD, whereas aquatic cases showed only 43% fit.

  • Saponification:

    • Recommendation to include saponification progression in scoring systems specifically for cold to temperate climates.

Methodology

  • Study Design: Retrospective analysis through autopsy reports, photos, and supporting documents from the NBFM digital database, covering cases from 2010 to 2020.

  • Sample Selection: Criteria included cases with outdoor recovery and PMI of six days or longer; excluded were cases involving minors, open investigations, and insufficient documentation.

  • Scoring System: Utilized established methods for terrestrial (TBS) and aquatic (TADS) cases; observations made through photographic documentation and autopsy reports.

Results Summary

  • Desiccation and Skeletonization Patterns:

    • Surface cases displayed skeletonization as early as 6 days postmortem.

    • Aquatic cases predominantly showed saponification rather than skeletonization, with partial or complete skeletonization observed at longer PMIs.

Implications and Future Research

  • Highlights need to adapt existing models for a colder climate context, especially refining ADD calculations for aquatic environments.

  • Future studies should focus on creating updated scoring methods that adequately integrate features like saponification to improve PMI estimations in Swedish conditions.

  • Advocacy for broader quantitative studies in the realm of forensic taphonomy to deepen understanding of environmental impacts on human decomposition.