An Improved Equation for TBS and ADD: Establishing a Reliable Postmortem Interval Framework for Casework and Experimental Studies

Document Type

Article

Source of Publication

Journal of Forensic Sciences

Publication Date

1-1-2016

Abstract

© 2016 American Academy of Forensic Sciences. Megyesi et al.'s (J Forensic Sci, 2005, 50, 618) paper was important to forensic anthropology as it introduced a quantitative framework for estimating time since death in human cadavers, based upon physical appearance by way of scoring on a novel scale. However, errors concerning rounding, temperature scale, and incorrect use of a statistical regression model render their predictive formula unusable. Based upon only their more reliable data, a more appropriate regression model to predict accumulated degree days (ADD) from total body score (TBS) is presented. The new model is also a superior fit (r2 = 0.91) and produces markedly narrower confidence intervals than the original, which also allowed impossible, negative ADD values. Explanations of the shortcomings in the original analysis and calculations are presented, which it is hoped will help forensic scientists avoid making similar mistakes.

ISSN

0022-1198

Publisher

Blackwell Publishing Inc.

Volume

61

First Page

201

Last Page

207

Disciplines

Life Sciences

Keywords

Accumulated degree days, Decomposition, Forensic science, Forensic taphonomy, Inverse prediction, Regression models, Statistical models

Scopus ID

84939865461

Indexed in Scopus

yes

Open Access

no

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