Chapter II
THE FREEDOMS, RIGHTS AND OBLIGATIONS OF PERSONS AND CITIZENS
PERSONAL FREEDOMS AND RIGHTS
Article 42
1. Only a person who has committed an act prohibited by a statute in force at the moment of commission thereof, and which is subject to a penalty, shall be held criminally responsible. This principle shall not prevent punishment of any act which, at the moment of its commission, constituted an offence within the meaning of international law.
Non-retroactivity
Nullum crimen sine lege
Nulla poena sine lege
EDIT.