The introduction of fingerprinting around 1900 changed crime scene investigations radically. Police experts within the records departments experimented with techniques and chemicals to find a way of making fingerprints visible and fileable. This strengthened the role of material evidence, and police work saw a professionalisation in two ways: On the one hand, the police records departments launched an expanding system of identification based on biometric techniques, since the most important part of the identification procedure was to classify and to archive the traces in a way to enable distinct correlations between traces and offender. On the other hand, police experts represented dactyloscopy as an identification technique in public as they prepared and presented expert testimonies in court, where they had to establish fingerprinting as evidence without doubt. Franz Eichberg, the head of the Viennese records department in the 1920s, was welcomed in court by mistrust: “Mr authorised expert today you won't be in luck with your dactyloscopy, as our jurymen are not ready yet for your dactyloscopy.”