Parliamentary commissions of inquiry have been a major event on LCP and Public-Sénat since the channels were created 20 years ago. These long filmed interrogation sessions have even produced some of the best audiences for both channels. Some scenes have become cult, such as the exchange of words between Senator Philippe Bas and Alexandre Benalla or the interrogation of Fabrice Burgaud, the young investigating judge in the Outreau affair, trying to justify sending thirteen innocent people to prison. During his first intervention in the Senate in July 2020, the new Minister of Justice Eric Dupond-Moretti explained that he would draw inspiration from the work of the Outreau commission of inquiry, in which he had participated, and on which he testifies in the documentary. Provided for by the Constitution of the Fifth Republic, these commissions have acquired a new status over the past two decades, through the impact of their live broadcast. A look back at four commissions that have particularly left their mark. The first coincided with the very birth of the two parliamentary channels, in 2000; it investigated Mad Cow disease, a major food scandal in France and Europe. The second commission, in 2006, indicted the judicial system, following the catastrophe of the Outreau pedophilia trial. The third, in 2012, saw the summoning of several members of the Hollande government, regarding the account hidden in Switzerland by the Minister of the Budget Jérôme Cahuzac. The fourth, in 2018, went all the way to the Élysée, following the escapades of Alexandre Benalla, Emmanuel Macron's bodyguard. Four cases that have captivated public opinion and caused tensions at the highest level of the State. But were these commissions of inquiry really independent? Did they advance the truth? What sanctions were taken? And were the recommendations made by the elected officials in their final report followed up? In this documentary "Investigations in Parliament", journalist and director Stéphane Haumant interviewed the main players in these key moments of public life: parliamentarians, witnesses heard and journalists. They recount the key moments and reveal what goes on behind the scenes. Among the personalities interviewed: MPs and senators Muriel Jourda, André Vallini, Philippe Houillon, Georges Fenech, Charles de Courson, Danniel Fasquelle and Alain Claeys; Abbé Wiel ("acquitted" of Outreau), former lawyer Eric Dupond-Moretti, journalists Florence Aubenas, Ariane Chemin, Sophie Coignard, Gérard Leclerc, Fabrice Arfi, Daniel Schneidermann and Thomas Snegaroff. A dive into the heart of the democratic machine, which sheds light on twenty years of evolution in our society. Director: Stéphane Haumant