How reliable is the charred body scale? An interobserver reliability study on scoring burned remains

Area of Science:

• Forensic Science
• Anthropology
• Postmortem Interval Estimation

Background:

• Accurate assessment of decomposition in burned remains is crucial for forensic investigations.
• Existing methods like the charred body scale require evaluation for reliability across different burn severities.
• The Crow Glassman Scale (CGS) categorizes burn severity from epidermal blistering (CGS level 1) to cremation (CGS level 5).

Purpose of the Study:

• To evaluate the interobserver reliability of the charred body scale across different burn levels.
• To determine if the charred body scale is a reliable tool for quantifying decomposition in burned remains.
• To identify potential limitations of the charred body scale in forensic casework.

Main Methods:

• Fifty-one photographic files of burned pig remains, subjected to CGS levels 1-3, were scored by nine participants using the charred body scale.
• Participants treated each photograph as a unique forensic case with unknown initial burn level and decomposition stage.
• Interobserver reliability was assessed using individual and average absolute agreement intraclass correlations.

Main Results:

• The charred body scale demonstrated reliability for burned remains classified as CGS level 1.
• Reliability significantly decreased for remains burned to CGS levels 2 and 3.
• Scoring errors were noted at higher burn levels, suggesting limitations in the scale's applicability.

Conclusions:

• The charred body scale is a reliable tool for assessing decomposition in burned remains only at lower burn levels (CGS 1).
• Higher burn levels (CGS 2-3) introduce significant interobserver error, compromising the scale's reliability.
• A universal scoring method accounting for multiple burn levels within a single case is recommended for forensic applications.