presumed lack of due diligence in the investigation, its lack of effectiveness and impartiality and its failure to fulfill its obligation to investigate within a reasonable time. Finally, the representatives pointed out that the remedies contemplated in the legislative reforms of 2010 and 2011, mentioned by the State, were not available to the family members when the events took place. A.2. Considerations of the Court 20. Article 46(1)(a) of the American Convention establishes that for a petition or complaint filed before the Inter-American Commission to be admissible under Article 44 of the Convention, domestic remedies must have been pursued and exhausted in accordance with generally recognized principles of International Law. 8 However, this is subject to principles of substance and form. In terms of substance, as the Court has determined in its case law since the first contentious case was brought before it, that this not only refers to the formal existence of such remedies, but also to their adequacy and effectiveness, as stated in the exceptions set forth in Article 46(2) of the Convention. 9 In formal terms, an objection to the Court’s jurisdiction, based on a supposed failure to exhaust domestic remedies, must be filed at the appropriate procedural stage, 10 that is, during the early stages of the admissibility proceeding before the Commission, 11 and it should specify precisely which remedies must be exhausted and their effectiveness. For more than two decades, the Court’s interpretation of Article 46(1) (a) of the Convention has been in keeping with international law, 12 according to which, after the appropriate procedural stage the principle of procedural preclusion comes into operation. 13 21. First, the Court notes that, during the admissibility proceeding before the Commission, the State followed two different lines of argument regarding the failure to exhaust domestic remedies. On the one hand, in the first two briefs submitted to the Commission, it argued that “the remedies of the domestic jurisdiction have not yet been exhausted, and the investigation by the Public Prosecution Service is still pending conclusion”; therefore, the petition “bec[ame] inadmissible.” 14 On the other hand, Guatemala submitted a third brief in which it stated that “[e]ven though the domestic remedies of the legal process have not yet been exhausted, the State, upon recognizing that there has not been substantial progress, cannot deny the petition of family [A.].” 15 This argument did not include an expression of its willingness to find a possible solution under the terms of Article 49 of the Convention. Subsequently, the State submitted five briefs in which it reiterated its position 16 and, specifically, in two of them 17 indicated that : In view of the fact that this case is currently in the admissibility phase, the State of Guatemala reiterates the position expressed […], in the sense that, despite the fact that the domestic remedies of the criminal proceedings have not yet been exhausted, it does not oppose the petition of the family [A], without prejudice to any position that it may adopt in future regarding the merits of the petition. 22. In this regard, the Court confirms that the initial petition consisted of an account of the facts, which included information concerning the alleged victims, the nature or origin of the supposed violation and those responsible for it; consequently, it was based on this body of facts that the State said it did not oppose the petition. Therefore, even though the 8 Cf. Case of Velásquez Rodríguez v. Honduras. Preliminary Objections. Judgment of June 26, 1987. Series C No. 1, para. 85, and Case of Brewer Carías v. Venezuela, supra, para. 83. 9 Cf. Case of Velásquez Rodríguez v. Honduras. Merits. Judgment of July 29, 1988. Series C No. 4, para. 63, and Case of Brewer Carías v. Venezuela, supra, para. 83 10 Cf. Case of Velásquez Rodríguez v. Honduras. Preliminary Objections, supra, para. 88, and Case of Brewer Carías v. Venezuela, supra, para. 37. 11 Cf. Case of Herrera Ulloa v. Costa Rica. Preliminary Objections, Merits, Reparations and Costs. Judgment of July 2, 2004. Series C No. 107, para. 81, and Case of Brewer Carías v. Venezuela, supra, para. 37. 12 Cf. Case of Reverón Trujillo v. Venezuela. Preliminary Objection, Merits, Reparations and Costs. Judgment of June 30, 2009. Series C No. 197, para. 22, and Case of Brewer Carías v. Venezuela, supra, para. 84. 13 Cf. Case of Mémoli v. Argentina. Preliminary Objections, Merits, Reparations and Costs. Judgment of August 22, 2013. Series C No. 265, para. 47, and Case of Brewer Carías v. Venezuela, supra, para. 37. 14 Cf. Briefs of the State of Guatemala of June 20 and October 2, 2006 (File of the proceedings before the Commission, pages 433 and 400). 15 Cf. Brief of the State of Guatemala of July 23, 2008 (File of the proceedings before the Commission, page 379). 16 Cf. Briefs of the State of Guatemala of November 14, March 27, April 14, July 28 and November 3, 2009 (File of the proceedings before the Commission, pages 358, 331, 321, 287 and 263). 17 Cf. Briefs of the State of Guatemala of April 14 and July 28, 2009 (File of the proceedings before the Commission, pages 321 and 287). 9