should initiate a serious, impartial and effective investigation, ex oficio,282 which should be carried out within a reasonable time.283 As established by the Commission: The judicial investigation must be undertaken in good faith and must be diligent, exhaustive and impartial and geared to exploring all possible lines of investigation that make it possible to identify the perpetrators of the crime, so that they can be tried and punished.284 196. On the content of the duty to investigate with “due diligence”, the Inter-American Court has established that the investigation should be undertaken utilizing all legal means available and should be oriented toward the determination of the truth.285 The Court has also stated that the State must ensure the right of the victim or his or her next of kin to learn the truth about what happened and for those responsible to be punished,286 and involving every State institution .287 The IACHR recalls that the obligation to investigate and punish every act that entails a violation of the rights protected by the Convention requires that not only the direct perpetrators of human rights violations be punished, but also the masterminds.288 197. The Court has also stated that the competent authorities adopt all reasonable measures to guarantee the necessary probative material in order to carry out the investigation.289 198. Even when the obligation to investigate is an obligation of means, rather than results, it must be carried out in all seriousness and not as a mere formality predestined to be unsuccessful or ineffective,290 or as a mere reaction to private interests, which would depend on the procedural initiative of the victims or their family members or on the submission of evidentiary elements by private individuals.291 199. Under the aforementioned precedents, the Commission will analyze if in the instant cases the State of Colombia carried out a serious and diligent investigation within a reasonable time, on the facts 282 I/A Court H.R., Case of García Prieto et al. v. El Salvador. Preliminary Objections, Merits, Reparations, and Costs. Judgment of November 20, 2007. Series C No. 168, para. 101; I/A Court H.R., Case of the Gómez Paquiyauri Brothers v. Peru. Merits, Reparations and Costs. Judgment of July 8, 2004. Series C No. 110, para. 146; and 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. 283 I/A Court H.R., Case of Bulacio v. Argentina. Merits, Reparations and Costs. Judgment of September 18, 2003. Series C No. 100, para. 114; I/A Court H.R., Case of the Rochela Massacre v. Colombia. Merits, Reparations and Costs. Judgment of May 11, 2007. Series C No. 163, para. 146; and I/A Court H.R., Case of the Miguel Castro Castro Prison v. Peru. Merits, Reparations and Costs. Judgment of November 25, 2006. Series C No. 160, para. 382. 284 IACHR, Report No. 37/00, Case 11.481, Monsignor Oscar Arnulfo Romero y Galdámez, El Salvador, April 13, 2000, para. 80. I/A Court H.R., Case of García Prieto et al. v. El Salvador. Preliminary Objections, Merits, Reparations, and Costs. Judgment of November 20, 2007. Series C No. 168, para. 101. 285 286 I/A Court H.R., Case of Bulacio v. Argentina. Merits, Reparations and Costs. Judgment of September 18, 2003. Series C No. 100, para. 114; I/A Court H.R., Case of the Rochela Massacre v. Colombia. Merits, Reparations and Costs. Judgment of May 11, 2007. Series C No. 163, para. 146; and I/A Court H.R., Case of the Miguel Castro Castro Prison v. Peru. Merits, Reparations and Costs. Judgment of November 25, 2006. Series C No. 160, para. 382. 287 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; I/A Court H.R., Case of the Pueblo Bello Massacre v. Colombia. Merits, Reparations and Costs. Judgment of January 31, 2006. Series C No. 140, para. 120; and I/A Court H.R., Case of Huilca Tecse v. Peru. Merits, Reparations and Costs. Judgment of March 3, 2005. Series C No. 121, para. 66. 288 IACHR, Report on the Situation of Human Rights Defenders in the Americas, OEA/Ser.L/V/II.124. Doc. 5 rev.1, 7 March 2006, para. 109. 289 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. 290 I/A Court H.R., Case of Velásquez Rodríguez v. Honduras. Merits. Judgment of July 29, 1988. Series C No. 4, para. 177; 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. 131; and 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. 120. 291 I/A Court H.R., Case of Velásquez Rodríguez v. Honduras. Merits. Judgment of July 29, 1988. Series C No. 4, para. 177; and 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. 120.