or, in the case of Ana Rosa Castiblanco Torres, that her whereabouts were unknown for 16 years. 300. In 1986, the Special Court concluded that the persons “considered disappeared,” “died on the fourth floor” (supra para. 159). According to the testimony of César Rodríguez Vera, this “result provided the State with grounds for denying the existence of the disappeared for many years.” 468 Added to what it has determined in the pertinent section (supra para. 298), the Court stresses that this theory has been rejected by the criminal courts that have heard the case in first instance in three separate judgments, where it has been concluded that the victims were forcibly disappeared (supra paras. 175, 183, 185 and 186). These decisions were partially confirmed in two of the cases, in which the enforced disappearance of some of the presumed victims has been considered proved and nullity has been declared with regard to the others finding that further investigations were required (supra paras. 177 to 180 and 188). 469 In one of the proceedings, the Superior Court affirmed that “the Colombian State has not complied with its obligation to take all necessary measures to clarify the true situation [of the presumed disappeared victims].” 470 301. In this regard, it is possible to consider that a failure by the State to comply with the obligation of due diligence in a criminal investigation may lead to the lack of sufficient evidence to clarify the events that are being investigated, to identify the possible authors and participants, and to determine the eventual criminal responsibilities at the domestic level. Consequently, an acquittal could be considered a factor when evaluating the State’s responsibility or the scope of this, but does not constitute per se a factor to affirm the State’s lack of international responsibility, in view of the difference in the probative standards or requirements between criminal matters and international human rights law. 471 However, there are no acquittals in this case, but only two nullifications decided in the proceedings. The decisions made in the second instance judgments do not necessarily mean that this Court has insufficient evidence to consider that these persons were victims of forced disappearance, but rather that the investigation has not been conducted properly. 302. Consequently, the Court notes that, in three first instance judgments it was concluded, based on the existing evidence and indications, that what happened to eleven of the presumed victims in this case was a forced disappearance. Even the two second instance judgments delivered to date also considered, based on the existing evidence, that at least some of them had been victims of enforced disappearance and that the same could not be concluded for the others because insufficient evidence existed under the evidentiary standards of the criminal jurisdiction, and they therefore declared the nullification and ordered the continuation of the investigations (supra para. 300). However, they did not reject this possibility or consider that the disappeared persons had died in the Palace of Justice. Throughout the 29 years since the events, most of the evidence and indications that have emerged support the hypothesis of the forced disappearance of these persons. The State has substantiated the hypothesis of their death during the events on the grounds of its own negligence; negligence that has been found so severe that domestic courts and the Truth Commission have considered that it was aimed at concealing the facts. Consequently, 468 Testimony of César Rodríguez Vera during the public hearing on the merits in this case. 469 In the proceedings against the Commander of the Cavalry School, the Court concluded that Carlos Augusto Rodríguez Vera and Irma Franco Pineda were forcibly disappeared (supra para. 177). And in the proceedings against the Commander of the 13th Brigade, the Superior Court concluded that Carlos Augusto Rodríguez Vera, Bernardo Beltrán Hernández, Luz Mary Portela León, David Suspes Celis and Irma Franco Pineda were forcibly disappeared (supra para. 188). 470 Cf. Judgment of the Superior Court of Bogota of January 30, 2012 (evidence file, folio 23283). 471 Cf. Case of Osorio Rivera and family members v. Peru. Preliminary objections, merits, reparations and costs. Judgment of November 26, 2013. Series C No. 274, para. 144. 107