In criminal proceedings jurors often deal with circumstantial evidence. When the charge has not been proved beyond reasonable doubt, most legal systems state that the jury must give the accused the benefit of the doubt and return a verdict of not guilty according to the well-established principle in dubio pro reo. In Scottish law tradition, however, jurors have three-verdicts options, that is guilty, not guilty, and not proven. The verdict of not proven is a very peculiar aspect of the trial by jury in Scotland: this kind of deliberation is the subject of an intense discussion nowadays as well as in the past. The present work focuses on this topic by adopting a historical approach and investigating both the doctrinal debate and a number of case studies. Taking inspiration from a proposal made by Enrico Ferri in 1880, the article also examines the decision-making procedure in the Italian jury system, embracing a perspective which has so far remained unexplored: a comparative analysis of the Scottish experience and the Italian tradition in the nineteenth and early twentieth centuries. The research identifies a number of points of contact between the two jurisdictions, although they were governed by different rules and practices.