A judicial investigation (information judiciaire, or instruction judiciaire) is an inquiry led by an investigating judge (juge d'instruction) and closely regulated by the Code of Criminal Procedure.
It is mandatory for felonies (murder, premeditated murder…) and optional for misdemeanours (drug trafficking, organised fraud, procuring…). It generally concerns the most serious or most complex cases.
People against whom there is serious or corroborating evidence of having committed an offence are formally placed under investigation (mise en examen). This status makes it possible to ask the investigating judge to carry out investigative steps, and also to ask the investigating chamber to annul the proceedings on the grounds of procedural defects.
A judicial investigation involves standard steps taken by the investigating judge, such as questioning, during which the lawyer is present after having been able to consult the case file — access that makes it possible to build a coherent and effective defense.
The lawyer may submit observations to the judge on the legal characterisation of the alleged offences, or request the return of seized property or funds.
A person under investigation may be subject to a security measure: judicial supervision (contrôle judiciaire) or pre-trial detention. Judicial supervision may come with obligations and prohibitions listed in Article 138 of the Code of Criminal Procedure, and the lawyer may request that they be temporarily lifted or modified.
Pre-trial detention must meet the criteria set out in Article 144 of the Code of Criminal Procedure. It cannot be ordered by the investigating judge: only the Liberty and Custody Judge (Juge des Libertés et de la Détention) can order it, after an adversarial hearing at which the lawyer presents arguments.
The length of pre-trial detention (or of the committal order) varies according to the alleged offence. At any time, the lawyer of a person held in pre-trial detention may file an application for release.
Handling a judicial investigation requires thorough knowledge of the Code of Criminal Procedure and of the case law of the Court of Cassation, as well as particular responsiveness and a strategic view of everything at stake in the case.
