CCPR/C/GC/35 in accordance with domestic law. Consideration for parole or other forms of early release must be in accordance with the law56 and such release must not be denied on grounds that are arbitrary within the meaning of article 9. If such release is granted upon conditions and later the release is revoked because of an alleged breach of the conditions, then the revocation must also be carried out in accordance with law and must not be arbitrary and, in particular, not disproportionate to the seriousness of the breach. A prediction of the prisoner’s future behaviour may be a relevant factor in deciding whether to grant early release.57 21. When a criminal sentence includes a punitive period followed by a non-punitive period intended to protect the safety of other individuals,58 then once the punitive term of imprisonment has been served, to avoid arbitrariness, the additional detention must be justified by compelling reasons arising from the gravity of the crimes committed and the likelihood of the detainee’s committing similar crimes in the future. States should only use such detention as a last resort and regular periodic reviews by an independent body must be assured to decide whether continued detention is justified.59 State parties must exercise caution and provide appropriate guarantees in evaluating future dangers. 60 The conditions in such detention must be distinct from the conditions for convicted prisoners serving a punitive sentence and must be aimed at the detainee’s rehabilitation and reintegration into society.61 If a prisoner has fully served the sentence imposed at the time of conviction, articles 9 and 15 prohibit a retroactive increase in sentence and a State party may not circumvent that prohibition by imposing a detention that is equivalent to penal imprisonment under the label of civil detention. 62 22. The third sentence of paragraph 1 of article 9 provides that no one shall be deprived of liberty except on such grounds and in accordance with such procedure as are established by law. Any substantive grounds for arrest or detention must be prescribed by law and should be defined with sufficient precision to avoid overly broad or arbitrary interpretation or application.63 Deprivation of liberty without such legal authorization is unlawful.64 Continued detention despite an operative (exécutoire) judicial order of release or a valid amnesty is also unlawful.65 23. Article 9 requires that procedures for carrying out legally authorized deprivation of liberty should also be established by law and States parties should ensure compliance with their legally prescribed procedures. Article 9 further requires compliance with domestic rules that define the procedure for arrest by identifying the officials authorized to arrest 66 or 56 57 58 59 60 61 62 63 64 65 66 1388/2005, De Léon Castro v. Spain, para. 9.3. 1492/2006, Van der Plaat v. New Zealand, para. 6.3. In different legal systems, such detention may be known as “rétention de sûreté”, “Sicherungsverwahrung” or, in English, “preventive detention”; see 1090/2002, Rameka v. New Zealand. Ibid., para. 7.3. See concluding observations: Germany (CCPR/C/DEU/CO/6, 2012), para. 14. 1512/2006, Dean v. New Zealand, para. 7.5. 1629/2007, Fardon v. Australia, para. 7.4. See concluding observations: Philippines (CCPR/CO/79/PHL, 2003), para. 14 (vagrancy law vague), Mauritius (CCPR/CO/83/MUS, 2005), para. 12 (terrorism law), Russian Federation (CCPR/C/RUS/CO/6, 2009), para. 24 (“extremist activity”), and Honduras (CCPR/C/HND/CO/1, 2006), para. 13 (“unlawful association”). 702/1996, McLawrence v. Jamaica, para. 5.5: “the principle of legality is violated if an individual is arrested or detained on grounds which are not clearly established in domestic legislation”. 856/1999, Chambala v. Zambia, para. 7.3; 138/1981, Mpandanjila et al. v. Zaire, para. 10. 1461/2006, 1462/2006, 1476/2006, 1477/2006, Maksudov et al. v. Kyrgyzstan, para. 12.2. 7