75 pattern of human rights violations at the time, in order to to ensure that the pertinent proceedings and investigations are conducted taking into consideration the complexity of these facts and the context in which they occurred, avoiding omissions in gathering evidence and in following up on logical lines of investigation; (b) Determine the intellectual actors and perpetrators of the detention and subsequent forced disappearance of Messrs. Rainer Ibsen Cárdenas and José Luis Ibsen Peña. In addition, since this case involves serious human rights violations, and considering the nature of the facts, the State may not apply amnesty laws or argue statute of limitations, non-retroactivity of the criminal law, res judicata, or the non bis in idem principle or any other similar mechanism that excludes responsibility, in order to exempt itself from this obligation, and (c) Ensure that the competent authorities conduct the corresponding investigations ex officio and, to this end, that they have and use all necessary logistic and scientific resources for gathering and processing evidence and, in particular, have the powers to access the pertinent documentation and information to investigate the facts denounced and to carry out promptly those essential actions and inquiries to clarify what happened to Rainer Ibsen Cárdenas and José Luis Ibsen Peña; that those who take part in the investigation, including the victims’ next of kin, witnesses and judicial authorities, have appropriate guarantees for their safety and abstain from acts that obstruct the advance of the investigative proceedings. 238. Lastly, based on its case law,266 the Court consideres that the State must ensure the victim’s next of kin full access and capacity to act at all stages of the investigation and prosecution of those responsible, in accordance with domestic law and the provisions of the American Convention. In addition, the results of the corresponding proceedings must be publicized so that Bolivian society may know the facts of this case, as well as those responsible.267 C. Measures of satisfaction, rehabilitation and guarantees of non-repetition C.1 Determination of the whereabouts of José Luis Ibsen Peña 239. The Inter-American Commission indicated that the State “should initiate an exhaustive search to discover the whereabouts of José Luis Ibsen Peña, followed by the identification of his remains and their return to his family, if applicable.” 240. On this point, the representatives asked the Court to order the State to implement the necessary measures culminating in the return of the remains of José Luis Ibsen Peña to his family. 266 Cf. Case of the Caracazo v. Venezuela. Reparations and Costs. Judgment of August 29, 2002. Series C No. 95, para. 118; Case of Radilla Pacheco v. Mexico, supra note 8, paras. 247 and 334, and Case of Chitay Nech et al. v. Guatemala, supra note 6, para. 237. 267 Cf. Case of the Caracazo v. Venezuela. Reparations and Costs, supra note 266, para. 118; Case of Chitay Nech et al. v. Guatemala, supra note 6, para. 237, and Case of Manuel Cepeda Vargas v. Colombia, supra note 6, para. 217.