5 Convention on the Law of Treaties of 1969, they cannot, for reasons of internal law, stop assuming the international responsibility already established.3 6. The State Parties to the Convention shall guarantee the fulfillment of the treaty dispositions and its own effects (effet utile) within their respective domestic law. This principle is applied, not only regarding substantive rules of the human rights treaties (namely, the ones that contain dispositions regarding the protected rights), but also in relation with the law of procedure, such as those referred to the fulfillment of the decisions of the Court. These obligations shall be interpreted and applied within their respective domestic law. This principle applies, not only regarding substantive rules of the human rights treaties (namely, those that contain dispositions regarding the protected rights), but also regarding rules of procedure, such as the ones referring to the compliance with the decisions of the Court. These obligations shall be interpreted and applied in a manner that the protected guarantee is truly practical and effective, taking into account the special nature of the human rights treaties.4 1. Regarding the duty to observe the principle of legality and protection from ex post facto laws of the demands of legal due process in the second process against Mrs. De La Cruz Flores (first operative paragraph of the Judgment). 7. Before presenting the information and observations of the parties in the framework of the procedure of supervision of compliance of the present obligations ordered in the Judgment, the Court considers it pertinent to specify some background facts. 8. On November 21, 1996, Mrs. De La Cruz Flores was convicted to 20 years in prison by a “faceless” tribunal for the crime of collaboration with terrorism (hereinafter the “first process”).5 On June 20, 2003, the National Chamber of Terrorism declared null the prosecutorial charge and set it aside without effect in such first process, “without [varying] the legal situation [of the victim].” After said declaration of nullity, a new trial was brought forward (hereinafter the “second process”). On July 8, 2004, a request by the defense of the victim for a variation of the order of detention for one of restricted appearance was declared admissible, and the victim was effectively freed from prison the following days, namely, after eight years, two months and eleven days of being deprived of liberty. 9. In the second process, on July 10, 2006, the National Criminal Chamber issued a judgment in which the victim was convicted as “the author of the ‘crime against the Public Peace-Terrorism-Affiliation against the State,’ imposing upon her the sentence of deprivation of liberty for eight years, two months and eleven days, which was considered fulfilled.” Said judgment was the object of recourses of nullity by the defense of the victim as well as by the Prosecutor in the case, which derived in the Supreme Judgment of the Second Criminal Transitory Chamber of the Supreme Court of November 23, 2009, “which declar[ed] the nullity of the appealed judgment and reform[ing] it to impose 20 years of deprivation of liberty” and ordered “her location and capture.” 3 Cf. International Responsibility for the Promulgation and Enforcement of Laws in Violation of the Convention (Arts. 1 and 2 of the American Convention on Human Rights). Advisory Opinion OC-14/94 of December 9, 1994. Series A No. 14, par. 35; Case of Baena Ricardo et al. supra note 2, Considering fifth, and Case of Vargas Areco, supra note 2, Considering fourth. 4 Cf. Case of Ivcher Bronstein V. Peru. Jurisdiction. Judgment of September 24, 1999. Series C No. 54, par. 37; Case of Baena Ricardo et al., supra note 2, Considering sixth, and Case of Vargas Areco, supra note 2, Considering fifth. 5 Cf. Case of De la Cruz Flores V. Perú. Merits, Reparations and Costs. Judgment of November 18, 2004. Series C No. 115, par. 73.27.