The COMBI project, formally titled “Computer‑based forensic motion analysis for the identification of persons,” was carried out from 1 January 2021 to 30 April 2023 under the funding reference 13N15642. The sub‑project “Legal and Ethical Frameworks” was led by the University of Cologne, with the University of Mittweida responsible for the technical development of the digital skeleton (RIG) and the Police Department Göttingen providing an operational perspective on police use. The project was funded by the German Research Foundation (DFG) and aimed to create a legally compliant, ethically sound biometric identification method that could be integrated into the German criminal procedure law (StPO).

Technically, the core innovation is the RIG, a digital skeleton extracted from video recordings that serves as a passive biometric feature. Unlike facial recognition, which can fail when a suspect’s face is obscured or masked—error rates of up to 50 % have been reported—the RIG relies on anthropometric body measurements that remain visible even when the face is concealed. The RIG is derived from the video data and then matched against a database of known skeletons, enabling quantitative person assignment. The project demonstrated that the RIG can be used as an intelligent, image‑based forensic comparison tool, providing a reliable basis for evidence in criminal proceedings. While the report does not provide explicit numerical performance metrics for the RIG, it emphasizes that the method’s passive nature and reliance on body shape make it robust against common obfuscation tactics that defeat facial recognition systems.

The legal‑ethical analysis was structured into five categories. First, the constitutionality of processing video recordings and the application of the COMBI method was examined, ensuring compliance with fundamental rights. Second, the research was evaluated against principles of applied machine and safety ethics, as well as practical, ethics‑based regulatory concepts. Third, the legal conformity of data protection and criminal procedure law was assessed. Fourth, conditions for standardising the development and application of the COMBI method were formulated, with a discussion of how these conditions affect the evidential value of RIG comparisons. Finally, the integration of the method into the StPO was considered, including the necessary legal adjustments to make the RIG a recognized forensic tool.

The project’s findings confirm that the RIG can be legally and ethically integrated into the German criminal justice system. The analysis concluded that the method satisfies constitutional requirements, aligns with data protection regulations, and can be incorporated into the StPO with appropriate amendments. The study also identified the need for ongoing oversight to maintain compliance as technology and legal standards evolve.

In terms of collaboration, the University of Cologne coordinated the legal and ethical oversight, ensuring that the method met high ethical standards and legal requirements. The University of Mittweida developed the RIG technology and conducted the technical validation. The Police Department Göttingen evaluated the method’s practicality for law enforcement, providing insights into operational deployment. The project’s duration of just over two years allowed for a comprehensive assessment of both technical performance and legal integration, culminating in a set of recommendations for embedding the COMBI method into routine forensic practice.