32 126. The Court has also said that “as a result of the protection granted by Articles 8 and 25 of the Convention, the States are obliged to provide effective judicial recourses to the victims of human 158 rights violations that must be substantiated according to the rules of due process of law.” 127. Regarding the duty of conducting an investigation with due diligence, the Inter-American Court has ruled that this means that inquiries must be pursued through all legal means available and 159 must be oriented toward the determination of the truth. The Court has further ruled that the State has the duty of ensuring that all steps necessary to learn the truth about what happened and for those 160 161 responsible to be punished are carried out, involving all institutions of the State in that undertaking. The Court has also said that the authorities must adopt all reasonable measures to guarantee the 162 necessary evidence in order to carry out the investigation. 128. Although the obligation of investigating is an obligation of means and not of results, it must be undertaken by the State as its own legal duty, and not as a mere formality preordained to be 163 ineffective, or as a step taken by private interests that depends upon the procedural initiative of victims 164 or their families or upon the offer of proof by private parties. 129. Regarding the State’s obligation of investigating complaints alleging forced disappearances, the Court has said that “faced with the particular gravity of such offenses and the nature of the rights harmed, the prohibition of the forced disappearance of persons and the corresponding 165 obligation to investigate and punish those responsible has attained the status of jus cogens.” Thus, whenever there is a reason to believe that a person has been subjected to forced disappearance, an …continuation Judgment of July 8, 2004, Series C No. 110, para. 146; I/A Court H. R., Case of Cantoral Huamaní and García Santa Cruz v. Peru, Preliminary Objection, Merits, Reparations, and Costs, Judgment of July 10, 2007, Series C No. 167, para. 130. 157 I/A Court H. R., Case of Bulacio v. Argentina, Judgment of September 18, 2003, Series C No. 100, para. 114; Case of the La Rochela Massacre v. Colombia, Judgment of May 11, 2007, Series C No. 163, para. 146; and Case of the Miguel Castro Castro Prison v. Peru, Judgment of November 25, 2006, Series C No. 160, para. 382. 158 I/A Court H. R., Case of Cantoral Huamaní and García Santa Cruz v. Peru, Preliminary Objection, Merits, Reparations, and Costs, Judgment of July 10, 2007, Series C No. 167, para. 124; Case of the La Rochela Massacre v. Colombia, Judgment of May 11, 2007, Series C No. 163, para. 145; Case of the Miguel Castro Castro Prison v. Peru, Judgment of November 25, 2006, Series C No. 160, para. 381; and Case of the Dismissed Congressional Employees (Aguado Alfaro et al.) v. Peru, Judgment of November 24, 2006, Series C No. 158, para. 106. 159 I/A Court H. R., Case of García Prieto et al. v. El Salvador, Preliminary Objection, Merits, Reparations, and Costs, Judgment of November 20, 2007, Series C No. 168, para. 101. 160 I/A Court H. R., Case of Bulacio v. Argentina, Judgment of September 18, 2003, Series C No. 100, para. 114; Case of the La Rochela Massacre v. Colombia, Judgment of May 11, 2007, Series C No. 163, para. 146; and Case of the Miguel Castro Castro Prison v. Peru, Judgment of November 25, 2006, Series C No. 160, para. 382. 161 I/A Court H. R., Case of Cantoral Huamaní and García Santa Cruz v. Peru, Preliminary Objection, Merits, Reparations, and Costs, Judgment of July 10, 2007, Series C No. 167, para. 130; Case of the Massacre of Pueblo Bello v. Colombia, Judgment of January 31, 2006, Series C No. 140, para. 120; and Case of Huilca Tecse, Judgment of March 3, 2005, Series C No. 121, para. 66. 162 I/A Court H. R., Case of Zambrano Vélez et al. v. Ecuador, Merits, Reparations, and Costs, Judgment of July 4, 2007, Series C No. 166, para. 122. 163 I/A Court H. R., Case of Velásquez Rodríguez v. Honduras, Judgment of July 29, 1988, Series C No. 4, para. 177; Case of Cantoral Huamaní and García Santa Cruz v. Peru, Preliminary Objection, Merits, Reparations, and Costs, Judgment of July 10, 2007, Series C No. 167, para. 131; and Case of Zambrano Vélez et al. v. Ecuador, Merits, Reparations, and Costs, Judgment of July 4, 2007, Series C No. 166, para. 120. 164 I/A Court H. R., Case of Velásquez Rodríguez v. Honduras, Judgment of July 29, 1988, Series C No. 4, para. 177; and Case of Zambrano Vélez et al. v. Ecuador, Merits, Reparations, and Costs, Judgment of July 4, 2007, Series C No. 166, para. 120. 165 I/A Court H. R., Case of Goiburú et al. v. Paraguay, Judgment on Merits, Reparations, and Costs, Judgment of September 22, 2006, Series C No. 153, para. 84; Case of Anzualdo Castro v. Peru, Judgment of September 22, 2009, Series C No. 202, para. 59; and Case of Radilla Pacheco v. Mexico, Preliminary Objections, Merits, Reparations, and Costs, Judgment of November 23, 2009, Series C No. 209, para. 139.