3. No sentence or security measure may be applied unless it is expressly sanctioned by a pre-existing law. 4. No one may be the object of a sentence or security measure that is more severe than those provided for at the moment of the conduct in question, or at that at which the prerequisites for the application of such a measure were fulfilled, while criminal laws whose content is more favourable to the accused person shall be applied retroactively. 5. No one may be tried more than once for commission of the same crime. 6. Citizens who are unjustly convicted have the right to the review of their sentences and to compensation for the damages they have suffered, as laid down by law. Article 30 (Limits on sentences and security measures) 1. No sentence or security measure that deprives or restricts freedom may be perpetual in nature or have an unlimited or undefined duration. 2. In cases of danger based on a serious psychic abnormality in which therapy in an open environment is impossible, security measures that deprive or restrict freedom may be successively extended for as long as the psychic state in question is maintained, but always by judicial decision. 3. Criminal liability is not transferable. 4. No sentence shall automatically involve the loss of any civil, professional or political right. 5. Convicted persons who are the object of a sentence or security measure that deprives them of their freedom retain their fundamental rights, save for the limitations that are inherent to the purpose of their convictions and to the specific requirements imposed by the execution of the respective sentences. Article 31 (Habeas corpus) 1. Habeas corpus is available to counter misuse of power in the form of illegal arrest, imprisonment or detention. Application for it must be made to the competent court. 2. Application for a habeas corpus order may be made by the person so arrested, imprisoned or detained, or by any citizen in possession of his political rights. 3. Within a time limit of eight days of an application for habeas corpus, the judge shall rule thereon in a hearing that shall be subject to the adversarial principle. Article 32 (Safeguards in criminal procedure) 1. Criminal procedure shall ensure all the safeguards of the defence, including the right to appeal. 2. Every accused person is presumed innocent until the sentence in which he was convicted has transited in rem judicatam, and must be tried as quickly as is compatible with the safeguards of the defence.