46 kind of facts to be repeated.184 Hence the importance that the State adopt all necessary measures to investigate and, as appropriate, punish those responsible; to establish the truth of what happened; to discover the whereabouts of the victims and inform their next of kin, and, as appropriate, to provide fair and adequate reparation. 127. The obligation to investigate human rights violations is one of the positive measures that States must adopt in order to guarantee the rights recognized in the Convention.185 Hence, since its first judgment, this Court has emphasized the importance of the State’s obligation to investigate and punish human rights violations,186 an obligation that acquires particular significance given the seriousness of the crimes committed and the nature of the rights harmed,187 as in this case that concerns the forced disappearance of children in the context of a systematic pattern of serious human rights violations. For this reason, these rights cannot be eliminated or conditioned by any kind of domestic legal provisions or acts. 128. This Court has already considered that, when a forced disappearance has occurred, it must be considered and treated as an illegal act whose consequences can include imposing punishments on those who commit, instigate, conceal, or in any way participate in its perpetration.188 Consequently, the Court has considered that a criminal investigation should be launched whenever there are reasons to suspect that a person has been subjected to forced disappearance.189 This obligation does not depend on a complaint being filed, as in cases of forced disappearance, international law and the general obligation to guarantee rights impose the obligation to investigate the case ex officio, without delay, and in a serious, impartial and effective manner. Thus the investigation does not depend on the procedural initiative of the victim or his next of kin or on the provision of probative elements by private individuals.190 This is a fundamental and determinant element for the protection of the rights affected by these situations.191 Consequently, the investigation must be conducted using all legal means available and aimed at determining the truth, and pursuing, capturing, bringing to trial, and eventually punishing all the masterminds and perpetrators of the facts, especially when State agents are or could be involved.192 Also, impunity193 must be 184 Cf. Case of Velásquez Rodríguez, supra note 23, para. 158; Case of Heliodoro Portugal, supra note 112, para. 116, and Case of La Cantuta v. Peru. Merits, reparations and costs. Judgment of November 29, 2006. Series C No. 162, para. 115. 185 Cf. Case of Velásquez Rodríguez, supra note 23, para. 166; Case of Gelman, supra note 16, para. 184, and Case of Gomes Lund et al. (Guerrilha do Araguaia), supra note 97, para. 138. 186 Cf. Case of Velásquez Rodríguez, supra note 23, para. 166. 187 Cf. Case of La Cantuta, supra note 184, para. 157; Case of Gelman, supra note 16, para. 183, and Case of Gomes Lund et al. (Guerrilha do Araguaia), supra note 97, para. 137. 188 Cf. Case of Velásquez Rodríguez, supra note 23, para. 175. 189 Cf. Case of Heliodoro Portugal, supra note 112, para. 65; Case of Gelman, supra note 16, para. 186, and Case of Gomes Lund et al. (Guerrilha do Araguaia), supra note 97, para. 108. 190 Cf. Case of Velásquez Rodríguez, supra note 23, para. 177; Case of Gelman, supra note 16, para. 186, and Case of Gomes Lund et al. (Guerrilha do Araguaia), supra note 97, para. 108. 191 Cf. Case of the Pueblo Bello Massacre v. Colombia. Merits, reparations and costs. Judgment of January 31, 2006. Series C No. 140, para. 145; Case of Gelman, supra note 16, para. 186, and Case of Gomes Lund et al. (Guerrilha do Araguaia), supra note 97, para. 108. 192 Cf. Case of Velásquez Rodríguez, supra note 23, para. 177; Case of Ibsen Cárdenas and Ibsen Peña, supra note 100, para. 155, and Case of Heliodoro Portugal, supra note 112, para. 144. 193 Impunity has been defined by the Court as the “the total lack of investigation, pursuit, capture, prosecution and conviction of those responsible for violations of the rights protected by the American Convention.” Cf. Case of the “White Van” (Paniagua Morales et al.), supra note 20, para. 173; Case of Vera Vera et al. v. Ecuador. Preliminary objection, merits, reparations and costs. Judgment of May 19, 2011. Series C No. 224, para. 97, and Case of Ibsen Cárdenas and Ibsen Peña, supra note 100, para. 172.