L'Orchestre rouge (1967) was even more successful.
In 1969 Perrault published a spy novel, Le dossier 51.
In 1978, Gilles Perrault published Le Pull-over rouge, a novel in which he criticized the method of investigation done by the French police around the 1974 death of an 8-year-old girl.
Christian Ranucci, a French citizen, was executed by guillotine for the murder on 28 July 1976.
Perrault's case, calling Ranucci's guilt into question, held a great influence in the debate upon capital punishment in France.
It has reportedly had a notable impact upon a part of public opinion, having sold over 1 million copies.
Perrault was condemned twice, however, for his claims and papers about this case: in 1989 for having talked in a TV program of "abuse of authority" about the policemen in charge of the investigation (fined 30,000 francs to each person defamed at first instance, 40,000 on appeal in 1990, then 70,000 francs to each of the five plaintiffs on cassation in 1992, as well as the presenter); and in 2008 he and his publisher Fayard were found guilty of defamation toward the Marseille police in the book L'Ombre de Christian Ranucci (fined 5,000 euros and his editor an equal sum, a decision confirmed on appeal in 2009 and granted 10,000 euros in damages to each of the four policemen defamed).In 1980, he created the TV Series Julien Fontanes, magistrat with Jean Cosmos.
In 1990 Perrault published Notre ami le roi (Our Friend the King, 1993) about the regime and human rights abuses of Hassan II, at the time king of Morocco, who had until then been reported positively because of his close relations with the Western world.