6 4. That, as previously held by this Court, the obligation to comply with the rulings of the Court conforms to a basic principle of the law on the international responsibility of States, according to which States are required to comply with their international treaty obligations in good faith (pacta sunt servanda) and, as provided for in Article 27 of the Vienna Convention on the Law of Treaties of 1969, States may not invoke their internal law to avoid established international responsibility.2 5. That the States Party to the Convention are required to guarantee compliance with its provisions and their effects (effet utile) at the level of their domestic law. This principle applies not only to the substantive provisions of human rights treaties (i.e., those dealing with the rights thereby protected), but also to procedural rules, such as those concerning compliance with the judgments of the Court. Such obligations are to be interpreted and enforced in a manner such that the protected guarantee is truly practical and effective, taking into account the special nature of human rights treaties.3 * * * 6. That, after assessing compliance with the Judgment, the Court in the instant case has noticed that, in relation with the removal of obstacles which have prevented those responsible for Myrna Mack-Chang's extra-legal execution from being punished, the State authorities have made headway towards imposing criminal liability upon the two authors of Myrna Mack-Chang's extra-legal execution. 7. In this regard, the Court is aware that on February 12, 1993, the Third Trial Court in Criminal Matters sentenced Mr. Noel de Jesús-Beteta to 25 years in prison for the murder of Myrna Mack. In addition, the Criminal Division of the Guatemalan Supreme Court of Justice by Judgment of January 14, 2004 issued by the Fourth Appellate Division, found Mr. Juan Valencia Osorio guilty of the murder of Myrna Mack-Chang and was consequently sentenced to thirty years in prison and the suspension of his political rights for the length of the sentence (Cf. para. 134.22 of the Judgment of November 25, 2003 and Considering clause No. 7 in the Court's Order of September 12, 2005, respectively). 8. After analyzing the investigations carried out at the domestic level, the convictions imposed and the proven facts in the Judgment, as well as the comments submitted by the representatives and the Commission, which demand merely that 2 Cfr. International Responsibility for the Promulgation and Aplication of Laws in Violation of the Convention (Arts. 1 and 2 of the American Convention on Human Rights). Consultive Opinion OC-14/94 of December 9, 1994. Series A No. 14, para. 35; Case of Baena-Ricardo et al v. Panama. Monitoring Compliance with Judgment. Order of the Inter-American Court of Human Rights of November 22, 2002, Considering paragraph 3; Case of García-Asto and Ramírez-Rojas, supra Note 1, Considering 6; and Case of Molina-Theissen v. Guatemala. Monitoring Compliance with Judgment. Order of the Inter-American Court of Human Rights of July 10, 2007, Considering paragraph 3. 3 Cfr. Case of Ivcher-Bronstein v. Peru. Compliance. Judgment of September 24, 1999. Series C No. 54, para. 37; Case of Gómez-Palomino v. Peru. Monitoring Compliance with Judgment. Order of October 18, 2007, Considering paragraph 4; and Case of García-Asto and Ramírez-Rojas, supra Note 1, Considering paragraph 7.