The DNAxs software suite: A three-year retrospective study on the development, architecture, testing and implementation in forensic casework

In forensic DNA casework software tools aid in the data management and efficient, with low risk for error, interpretation and comparison of DNA profiling data. The need for such software has grown with increased numbers of genetic markers, more sensitive analysis methods and growing numbers of crime scene samples send for DNA analysis. To that end, the DNA eXpert System, DNAxs, was developed. This study describes how the expert system was realized and how it evolved during the first three years after the initial implementation. Insight is given in the software architecture, its modular design enabling to communicate with various software systems and how this system was implemented in a casework setting. The importance of quality aspects are highlighted, such as (automated) software testing at various levels. The code coverage is presented as well as the numbers of software bugs that were discovered. These bugs were more severe in earlier software versions than in the more recent versions and did not affect the interpretation of DNA results. The usefulness of the overall software suite and automated steps in DNA profile interpretation were evaluated based on its usage in forensic DNA casework during the first three years after its implementation at the developing laboratory. Because of automated profile comparisons, cases with larger numbers of profiles can be handled, are less prone to error and are extremely less time consuming. The implementation of an integrated quantitative probabilistic genotyping module into DNAxs enabled a more efficient workflow as no longer data files have to be exported and imported into different software. Extensive automated software tests and an audit trail serve as quality aspects for the usage of DNAxs. In times of the pandemic this software was found even more valuable than ever thought as it enabled working from home and it proved robust when used with many simultaneous users. The DNAxs software is regarded future proof and many new features and applications are envisioned.