84 to investigate cases of violations of certain substantive right must be protected or ensured285. The duty to investigate “becomes particularly compelling and important in view of the seriousness of the crimes committed and the nature of the rights wronged”286, since the corresponding duty to investigate and punish those responsible has become jus cogens287. In cases of extrajudicial execution, forced disappearance, torture and other serious human rights violations, the Tribunal has considered that the realization of a prompt, serious, impartial and effective investigation ex officio, is a fundamental element and a condition for the protection of certain rights that are affected or annulled by these situations, such as the right to personal liberty, humane treatment and life288. It is considered in the instant case that impunity will not be eliminated unless it is accompanied by the determination of the general responsibility - of the State- and individuals- and the specific criminal responsibility of its agents or of individuals, which are complementary289. Considering the nature and seriousness of the facts in these cases, even in such situations of systematic human rights violation, the customary international and treaty law impose on State parties the obligation, among others, to conduct an investigation following the above mentioned characteristics, in accordance with the requirements of due process. Failure to conduct an investigation of these characteristics, in such situations, would entail the State’s international responsibility290. 299. The obligation to investigate “does not derive solely from the treaty norms of International Law binding upon the States Parties, but also from the domestic legislation that makes reference to the duty to investigate certain unlawful conducts”291. In such cases, the States Parties must establish, pursuant to the procedures and the relevant organs created by its constitutions and norms292, which unlawful conducts shall the State investigate ex officio and determine the specific way in which the criminal procedure shall be exercised at the domestic level, as well as the rules that allow aggrieved parties to report or exercise the criminal action and, if appropriate, participate during the investigation and criminal proceeding. In order to demonstrate that certain remedy, such as a criminal investigation, is appropriate, the State shall need to verify whether such domestic remedy is suitable to address an infringement of a legal right293. 285 Cf. Case of the Pueblo Bello Massacre V. Colombia, supra note 68, para. 142; Case of Heliodoro Portugal V. Panamá, supra note 20, para. 115; Case of Zambrano Vélez et al. V. Ecuador, supra note 32, para. 110. 286 Case of La Cantuta V. Perú, supra note 72, para. 157. Cf. Case of Goiburú et al. V. Paraguay, supra note 48, para. 128. 287 For example, in La Cantuta, it was determined that “the prohibition against the forced disappearance of people and the corresponding duty to investigate and punish those responsible has become jus cogens” Cf. Case of La Cantuta V. Perú, supra note 72, para. 157. 288 Cf. Case of the Pueblo Bello Massacre V. Colombia, supra note 68, para. 145; Case of Heliodoro Portugal V. Panamá, supra note 20, para. 115; and Case of La Cantuta V. Perú, supra note 72, para. 289 Cf. Cf. Case of Goiburú et al. V. Paraguay, supra note 48, para. 88. 290 Cf. Case of Velásquez Rodríguez, supra note 33, para. 166 and 176; Case of Godínez Cruz. Merits, supra note 100, para. 175; Case of Cantoral Huamaní and García Santa Cruz V. Perú, supra note 75, para. 102; Case of Miguel Castro-Castro Prison V. Perú, supra note 36, para. 119; Case of Ximenes Lopez V. Brazil, Merits, Reparations and Costs. Judgment of July 4, 2006. Series C No. 149, para. 147; Case of the Ituango Massacres, supra note 23, para. 297. 291 Case of García Prieto et al. V. El Salvador, supra note 48. para 104. 292 Cf. The Word “Laws” in Article 30 of the American Convention on Human Rights. Advisory Opinion OC6/86 of May 9, 1986, Series A Nº6, para. 32. 293 Cf. Case of Velásquez Rodríguez V. Honduras. Merits, supra note 33, para. 64.