Related Rule
France
Practice Relating to Rule 101. The Principle of Legality
In 2003, in the Aussaresses case, France’s Criminal Law Chamber of the Court of Cassation held:
Finding on the appeal lodged by the Movement against Racism and for Friendship between Peoples Mouvement contre le Racisme et pour l’Amitié entre les Peuples – MRAP], civil party,
Against the decision of the investigating chamber of the Court of Appeal of Paris of 14 December 2001, which confirmed the order of the investigating judge, refusing to hold an investigation upon its criminal complaint against an unnamed person for a count of crimes against humanity;
Whereas it follows from the decision attacked and from the documents of the proceedings that the Movement against Racism and for Friendship between Peoples, constituting itself as civil party, brought a criminal complaint against unnamed person for crimes against humanity, because of torture and summary executions which, in a book published on 3 May 2001, General Paul X … revealed having carried out or having ordered to be carried out against the civilian population, in Algeria between 1955 and 1957, while he was an intelligence officer in the service of the French army;
Whereas, to confirm the order, the investigating chamber upholds, in the grounds under appeal, that, impossible to be prosecuted under the classification of crimes against humanity, the denounced acts fall under the provisions of Law Nr. 68-697 of 31 July 1968 on amnesty;
Whereas by pronouncing thus, the judges have justified their decision;
Whereas the provisions of the law of 26 December 1964 and those of the Statute of the International Military Tribunal at Nuremberg, annexed to the London Charter of 8 August 1945, only concern the acts committed on behalf of the European Axis countries;
Whereas, furthermore, the principles of legality of crimes and penalties and of non-retroactivity of a more severe criminal law, set out by Article 8 of the Declaration of the [1789] Declaration of the Rights of Man and of the Citizen, Article 7-1 of the European Convention on Human Rights, Article 15-1 of the International Covenant on Civil and Political Rights, 111-3 and 112-1 of the Penal Code, are an obstacle to the application of Articles 211-1 to 212-3 of that Code, repressing crimes against humanity, to acts committed before their entry into force, 1 March 1994;
Whereas international custom cannot make up for the absence of a criminalizing text, under the classification of crimes against humanity, the acts denounced by the civil party;
From which follows that the appeal must be rejected. 
France, Court of Cassation, Aussaresses case, Appeal Nr. 02-80719, Judgment, 17 June 2003.
On the same day, the Court of Cassation, on the same grounds, rejected an appeal lodged by the International Federation for Human Rights [Fédération International des Ligues des Droits de l’Homme – FIDH] against a decision of the investigating chamber of the Court of Appeal of Paris relating to the same facts. 
France, Court of Cassation, Aussaresses case, Appeal Nr. 02-83986, Judgment, 17 June 2003.