International audience Dangerousness as a legal concept has certainly been integrated into the criminal law and criminal justice systems. This concept appears to be a topical issue within criminal policies whose main purpose is to ensure the protection of society. Nevertheless, the unpredictable nature of dangerousness has caused controversy among both legal professionals and clinical experts. Due to the lack of a specific definition of dangerousness as a legal concept and the interaction of psychiatric and criminological conceptions of dangerousness, the assessment of the concept turns out to be unreliable and consequently impairs the capacity of the legal system in treating it efficiently. Facing these difficulties, the legislator has however expressed his will to fight against dangerousness by implementing excessive security measures that threaten individual rights and whose compliance with the rules of due process of law remains questionable.