4 6. That the States Parties to the Convention are required to guarantee compliance with the provisions thereof and their effects (effet utile) at the domestic level. This principle is applicable not only with regard to the substantive provisions of human rights treaties (i.e. those dealing with the protected rights) but also with regard to procedural rules, such as those concerning compliance with the decisions of the Court. These obligations are to be interpreted and enforced in a manner such that the protected guarantee is truly practical and effective, bearing in mind the special nature of human rights treaties.4 7. That the Court considers that the hearing held to monitor compliance with the obligations that remain unfulfilled has been very useful. * * * 8. That, as regards the investigation, identification and punishment of the perpetrators and masterminds of the extrajudicial execution of Messrs. Carpio Nicolle, Villacorta Fajardo, Ávila Guzmán and Rivas González, as well as the serious injuries to Sydney Shaw Díaz (first operative paragraph of the Judgment), the State informed the Court that domestic authorities were able to find “a female eyewitness who says she recognized one of the individuals that participated in these incidents”; “interviews have been conducted with some other people [...] who suffered attacks in the same place where Mr. Jorge Carpio and others were murdered,” and that the Attorney General’s Office “is locating the National Civil Police officers employed in that jurisdiction at the time of the incidents in order to identify any other matters that could assist the investigation.” 9. That the representatives stated that impunity “is the State’s answer to this case.” They added that “even though Jorge Carpio was a prominent figure in Guatemalan society, four years after the Judgment was entered in this case, there has been no significant progress in the investigation into his extrajudicial execution and that of Alejandro Ávila Guzmán, Juan Vicente Villacorta Fajardo and Rigoberto Rivas González, as well as into the injuries caused to Shaw Díaz [...].” Furthermore, they stated that “the State’s report basically consists of a list of isolated actions and fails to indicate when they were taken or the line of investigation being pursued.” They added that, at the private hearing, the agent of the State simply mentioned that there had been “significant progress” and “further developments.” 10. That the Commission pointed out that “without undermining the significance of the investigative measures described [...], the Commission must express its concern over the fact that four years have elapsed since the entry of the Judgment, fifteen and a half years since [the] murder[s] and we are still in the same place we were when this case was brought before the Commission [and] before the Court.” The Commission added that “it is regrettable that in a case in which the State, during the hearing held before the Inter-American Court, publicly acknowledged its international responsibility, precisely due to lack of due diligence in the investigation process. That is, it is Considering clause No. 5; Case of the Dismissed Congressional Employees (Aguado-Alfaro et al.) v. Peru, supra note 2, Considering clause No. 4. 4 Cf. Case of Ivcher-Bronstein v. Peru. Competence. Judgment of September 24, 1999. Series C No. 54, para. 37; Case of the Sawhoyamaxa Indigenous Community v. Paraguay, supra note 2, Considering clause No. 6, and Case of Chaparro-Álvarez and Lapo-Íñiguez v. Ecuador. Monitoring Compliance with Judgment. Order of the Court of April 29, 2009, Considering clause No. 6.