Fast DNA reports for investigative leads in casework practice: An automated workflow for mixture analysis using...

Area of Science:

• Forensic Science
• Computational Biology
• Genetics

Background:

• Automated DNA analysis software streamlines forensic casework.
• Previous versions focused on single-source or major contributor DNA profiles.
• Advancements are needed to handle complex mixture DNA profiles.

Purpose of the Study:

• To extend the Fast DNA Identification Line (Fast ID Line) software to automatically analyze and report on mixture DNA profiles with up to four contributors.
• To enhance the software with advanced analytical rules, machine learning for contributor estimation, and probabilistic genotyping for database searching.
• To establish suitability criteria for automated DNA profile analysis and reporting.

Main Methods:

• Development of Fast ID Line v2.0 with extended profile analysis rules.
• Integration of a machine learning model for estimating the number of contributors in DNA mixtures.
• Implementation of a probabilistic genotyping model for efficient criminal DNA database searching.
• End-to-end testing using casework data to evaluate performance.

Main Results:

• Fast ID Line v2.0 delivered over 80% of DNA reports within three working days.
• The software retrieved 1.9-fold more candidates from database searches compared to v1.0.
• 72% of automatically reported candidates were also identified through manual casework analysis.
• Automated reports are utilized by law enforcement for intelligence-led investigations.

Conclusions:

• The Fast ID Line v2.0 significantly enhances the speed and efficiency of DNA mixture analysis.
• Automated reporting provides timely investigative leads, enabling faster law enforcement action.
• The software reduces the workload for DNA experts, requiring confirmation checks in most cases and saving valuable time.