Article 148-8 of the French Code of Criminal Procedure
Where the person under investigation intends to refer the matter to the Investigating Chamber pursuant to the provisions of Articles 140, third paragraph, 148, sixth paragraph, or 148-4, his request is made, in the forms provided for by articles 148-6 and 148-7, to the clerk of the relevant investigating chamber or to the head of the prison, who will ensure that it is forwarded. Where the president of the investigating…