By considering critics of research studies which take into consideration the ‘voice of prosecuted people’ before international criminal tribunals, this contribution develops a theoretical argument that would justify the recourse to the penal experience of prosecuted people in order to analyse the rationality and impact of international criminal justice. Our reasoning, based on conceptual landmarks drawn from the social sciences, allows us also to support a specific approach to the legal process as phenomenon. It is therefore not only addressed to sociologists, social psychologists and criminologists, but also to lawyers, who are, considering the foundations of their field, probably the most resistant to our perspective. The article expounds the necessity to establish a new approach: the respondents’ approach.