13. Antoine Quentin Fouquier-Tinville
Antoine Quentin Fouquier-Tinville was widely considered to be one of the most sinister figures of the revolution, particularly of the Reign of Terror. Having been trained in law, he was the public prosecutor, appointed by the Revolutionary Tribunal. However, many considered him to have carried out his duties in such a way that they only carried with them the appearance of legality when he was actually executing opponents to a political regime. As such, there was little need to establish actual guilt in the people that he sent to the guillotine.
Towards the end of his career (and life), he prosecuted a group of nuns, who had allegedly acted as fanatics against the state and attempted to foment rebellion and civil war by providing housing to enemies of the revolution. He labeled them criminal assassins, and the judge duly sentenced all of them, as well as those whom they had sheltered. One of the last people that he prosecuted was Robespierre himself, of whom he had previously been an ardent supporter.
When the Thermidorian Reaction began, following the fall of Robespierre, Fouquier-Tinville was tried with other former members of the Revolutionary Tribunal. They were found guilty and executed in May of 1795.