Article 407 of the French Code of Criminal Procedure
In the event that the accused, the civil party or the witness does not sufficiently speak the French language, or if it is necessary to translate a document submitted to the debates, the president shall appoint an interpreter ex officio, who must be at least twenty-one years of age, and shall make him/her take an oath to assist justice in his/her honour and conscience. The public prosecutor, the accused and…