Implementation of RNA profiling in forensic casework.

Area of Science:

• Forensic Science
• Molecular Biology
• Genetics

Background:

• Cognitive bias poses a significant challenge in forensic casework, potentially compromising the objectivity of results.
• Implementing RNA profiling requires a robust procedure to ensure unbiased interpretation and reliable casework outcomes.

Purpose of the Study:

• To develop and validate a stepwise procedure for unbiased RNA profiling in forensic casework.
• To assess the utility of RNA profiling for body fluid identification and its concordance with DNA analysis.
• To propose a framework for integrating RNA and DNA profiling results in forensic expert reports.

Main Methods:

• A stepwise protocol was designed to blind RNA researchers to case context and standardize result reporting.
• RNA profiling was conducted alongside standard DNA typing in seven mock cases involving various body fluid samples.
• Samples were processed using either presumptive testing with DNA typing or RNA/DNA co-extraction followed by profiling.

Main Results:

• The implemented procedure successfully minimized cognitive bias by separating RNA profiling from case context.
• RNA profiling results consistently agreed with presumptive testing and provided concordant DNA profiles.
• RNA profiling proved particularly valuable for distinguishing menstrual secretion from blood, identifying vaginal mucosa, and detecting skin cells.

Conclusions:

• The developed stepwise procedure ensures unbiased RNA profiling for reliable body fluid identification in forensic casework.
• RNA profiling complements DNA analysis, offering enhanced discriminatory power in specific forensic scenarios.
• Integrating RNA and DNA profiling results through hypothesis evaluation strengthens forensic conclusions and expert reporting.