Various cases illustrate loopholes and conflicts which have developed. For example, accused offenders can demand immediate release from preventive detention on grounds of procedural irregularities because their records were not placed at the disposal or their attorneys and the transacton recorded by the clerk of the court within 2 days of arrest. Any minor variation or delay in the formalities may be used by the accused to gain liberty. Futhermore, the arrest order continues in effect at all stages of the procedures unless rescinded by the examining judge, the advisory court, the court of arraignment, or the court of judgment, depending on the stage of proceedings, but the order is only valid for the specific acts for which it was issued. Consequently, an individual cannot be detained if the suspicions on which the writ of arrest was founded prove false, even though other crimes with irrefutable proof are uncovered. The complexities and historical development of the legal situation as well as the authorities' responsibilities at the various stages of proceedings are outlined. Modification of the articles of the code of criminal examination which bear directly on provisions related to preventive detention is recommended. Referral of offenders held in detention to correctional court should only be permitted in the case of crimes with penalties of more than 3 months. The advisory court responsible for the referral to correctional court may also be allowed to order release. The suspected offender should be held in detention if the court of judgment sentences him to imprisonment without probation for any crime even if he is acquitted or only placed on probation or fined for the offenses named in the writ of arrest. Extensive notes are supplied. --in French.