Evaluative sub-source and activity level reporting in Austria, Germany and Switzerland

Area of Science:

• Forensic genetics
• DNA analysis
• Legal applications

Background:

• Courtroom DNA questions are shifting from "Whose DNA?" (sub-source) to "How did it get there?" (activity level).
• Research on DNA transfer, persistence, prevalence, and recovery (TPPR) supports activity level assessments.
• The actual use of activity level reporting (ALR) in casework remains unclear.

Purpose of the Study:

• To investigate the practical relevance of activity level reporting (ALR) in forensic genetics casework in German-speaking countries.
• To determine if the scientific community's interest in ALR reflects actual casework demands.
• To assess trends in evaluative sub-source level reporting (ESSLR) and likelihood ratio (LR) calculations.

Main Methods:

• An online survey was conducted over three months in spring 2024.
• Fourteen institutes in Switzerland, Austria, and Germany participated.
• The survey assessed the perceived usefulness, knowledge, and frequency of ALR and ESSLR in casework.

Main Results:

• Participants believe ALR is useful but report limited knowledge and infrequent requests in practice.
• No significant increase in ALR reporting was observed over the last ten years.
• Most institutions use binary/semi-continuous software; LR calculations for single/major profiles and mixtures remained constant.

Conclusions:

• The perceived shift towards activity level reporting in forensic genetics has not yet occurred in German-speaking countries.
• Casework demands for ALR are currently low, despite growing academic interest.
• Evaluative sub-source level reporting remains prevalent, with stable likelihood ratio calculations.