47 eradicated by determining responsibilities, both general - of the State - and individual - criminal and any other kind of its agents or private individuals.194 In compliance with this obligation, the State must remove all de facto and the de jure obstacles that maintain impunity.195 129. In addition, in cases of forced disappearance, the investigation will have certain specific connotations that arise from the very nature and complexity of the phenomenon investigated; in other words, additionally, the investigation must include the implementation of all necessary measures to determine the fate of the victim and to discover his or her whereabouts.196 The Court has already established that the obligation to investigate facts of this nature subsists as long as the uncertainty about the final fate of the disappeared person remains, because the right of the victim’s next of kin to learn his or her ultimate fate and, if applicable, where their remains are, represents a fair expectation that the State must satisfy using all the means it has available.197 130. In brief, due to the nature and gravity of the facts, and especially if there is a context of systematic human rights violations, States have the obligation to carry out an investigation with the above-mentioned characteristics and to determine criminal responsibilities through the competent judicial authorities, strictly following the requirements of due process established in Article 8 of the American Convention.198 In addition, for the international community, the need to eradicate impunity obliges cooperation between States, which must adopt the necessary measures to avoid leaving these violations in impunity, either by exercising their jurisdiction to apply domestic and international law to prosecute and, as appropriate, punish those responsible, or by collaborating with other States that are doing so or seeking to do so.199 B. Obligation to open an investigation ex officio 131. The Inter-American Commission indicated that, even though the disappearance of the Contreras siblings had been “in the public domain since at least March 1993, when the Report of the Truth Commission that refers to them was issued,” it was not until March 16, 2000, that the State launched a criminal investigation into what happened, a fact that, in itself, implied “a disregard of the State obligation to initiate and pursue investigations ex officio, included in the obligation to provide effective remedies to the victims of [the] violations.” The Commission did not identify or specify in which part of the report or its attachments that reference appeared. For its part, the State expressly acknowledged this fact. 132. The evidence reveals that the report issued by the Truth Commission in 1993 (supra 194 Cf. Case of Goiburú et al., supra note 107, para. 131; Case of Chitay Nech et al., supra note 98, para. 199, and Case of Radilla Pacheco, supra note 25, para. 212 195 Cf. Case of La Cantuta, supra note 184, para. 226; Case of Chitay Nech et al., supra note 98, para. 199, and Case of Radilla Pacheco, supra note 25, para. 212. 196 Cf. Case of Ticona Estrada et al. v. Bolivia. Merits, reparations and costs. Judgment of November 27, 2008. Series C No. 191, para. 80; Case of Ibsen Cárdenas and Ibsen Peña, supra note 100, para. 152, and Case of Radilla Pacheco, supra note 25, para. 191. 197 Cf. Case of Velásquez Rodríguez. Judgment of July 29, 1988. Series C Godínez Cruz. Judgment of January 20, 1989. Series C No. 5, para. 191. No 4, para. 181, and Case of 198 Cf. Case of Huilca Tecse v. Peru. Merits, reparations and costs. Judgment of March 3, 2005. Series C No. 121, para. 106; Case of Vera Vera et al., supra note 193, para. 93, and Case of Ibsen Cárdenas and Ibsen Peña, supra note 100, para. 158. 199 Case of Goiburú et al., supra note 107, para. 131; Case of Anzualdo Castro, supra note 109, para. 125, and Case of La Cantuta, supra note 184, para. 160.