In the evening of July 13, 1793, Jean Paul Marat was assassinated by a young woman from Girondin called Charlotte Corday. Although historians tend to focus on Corday’s stabbing of Marat itself, studying her subsequent arrest allows one to raise other interesting questions. One of the questions is why was the crowd not allowed to execute summary justice and tear Corday apart on the spot? Here it is necessary to study the specific spatial and social context of the event: the quartier des Cordeliers and the sans-culotte house where Marat resided, as well as the heightened political awareness of the time, and finally the collective action of a series of groups and individuals. Crucial to the unfolding of events were of course not only Marat’s own immediate companions but also the “€œgardes nationaux”, the commissioner, the political élites and the ordinary citizens at the crime scene that evening. A study of these key players will enable us to explain why recourse to retribution by immediate violence was not undertaken and why a political and judicial solution was preferred.