To verify whether or not the conditions of detention violate the applicant’s dignity, the judge may:
1° Visit the place of detention;
2° Order an expert report entrusted to an expert registered on the lists of judicial experts or who has taken an oath in accordance with the article 160 ;
3° Request a bailiff to carry out any useful observations, photographs, filming and sound recordings within the prison, under conditions that respect the security requirements of the prison ;
4° Proceed with the hearing, if necessary by means of audiovisual telecommunication, of the applicant’s fellow inmates, prison staff or the head of the prison;
5° Proceed with the hearing of the applicant, even if the applicant has not asked to be heard by the judge pursuant to Article R. 249-35, in the presence, where appropriate, of his lawyer, if necessary by means of audiovisual telecommunication.
The judge may also consult any report describing the conditions of detention in question and resulting from a visit by an independent national or international body.