When an application for placement under house arrest with electronic surveillance is referred to him or when he is considering imposing such a measure, the investigating judge or the liberty and custody judge or, in the event of an appeal, the president of the investigating chamber may instruct the prison integration and probation service:
1° To ensure the availability of the technical device described in l’article R. 57-11 ou R. 61-22 as well as the technical feasibility of the project;
2° To verify the family, material and social situation of the person under investigation, in particular for the purpose of determining the times and places of assignment.
The referral for the purposes of the verifications mentioned in 1° above is mandatory in the cases provided for in 1° to 3° of article 142-6; however, in the cases provided for in 1° and 2° of this article, the investigating judge may take a specially reasoned decision not to proceed with the referral. This decision, which may not be appealed, may be included in the judge’s order referring the matter to the liberty and custody judge for the purpose of extending pre-trial detention.
In the case provided for by the last paragraph of article 142-6, this referral is made by the president of the investigating chamber.