The study presents an edition of a previously unknown manuscript by Vojta Náprstek from 1847, the original of which is deposited in the Vienna University Archive. It is a detailed description of Náprstek’s arrest and stay in custody in the year 1847; during his second year studying law in Vienna. This is an authentic testimony of Vojta Náprstek that he wrote as a defence after the police had warned the university about the incident. The document represents one of a few pieces of proof of Náprstek’s first clashes with the Austrian police. At the same time it allows a new, more sober interpretation of this event, than the one that used to be presented especially in older litetarure.