12. The Court also recalls that, in the Judgment,10 the State was ordered to remove all the de facto and de jure obstacles that maintained impunity in this case, and to conduct and conclude the pertinent investigations and proceedings ex officio, within a reasonable time, in order to establish the complete truth about the facts. To this end, the State must take into account the systematic pattern of human rights violations that existed at the time of the facts so that the pertinent investigations and proceedings are conducted taking into consideration the complexity of the events and of the context in which they occurred, avoiding omissions in the collection of evidence and in following up on logical lines of investigation.11 In addition, since grave human rights violations are involved, the State may not apply amnesty laws or argue prescription, non-retroactivity of the criminal law, res judicata, or the principle of non bis in idem, or any other similar mechanism that eliminates responsibility, in order to exempt itself from this obligation.12 13. Furthermore, the State must ensure that the persons who take part in the investigation, including the victims’ next of kin, witnesses, and agents of justice, have appropriate guarantees for their safety, and that the victims’ next of kin have full access and legal standing at all stages of the investigation and prosecution of those responsible, pursuant to domestic law and the norms of the American Convention. In addition, the results of the corresponding proceedings must be publicized so that Bolivian society may be made aware of the facts that are the purpose of this case, as well as of those responsible.13 B) Obligation to continue an effective search for the whereabouts of José Luis Ibsen Peña (ninth operative paragraph of the Judgment) 14. The State advised that it was “currently expediting the processing of information and taking steps to ensure technical cooperation for the effective search for the whereabouts of José Luis Ibsen Peña” through the Inter-institutional Council for the Clarification of Forced Disappearances (hereinafter “CIEDEF”), which “was attached to the Vice Ministry of Justice and Fundamental Rights, headed by the Ministry of Justice.14 In a note dated September 30, 2011, Bolivia advised that “this State portfolio […] had advised that, in an official request of January 31, 2011, made by the Prosecutor for this matter, […] the Institute of Forensic Investigations was asked to make an anthropological and genetic examination of the remains collected in August 2006 in the “La Cuchilla” Cemetery in Santa Cruz. Accordingly, on September 12, 2011, an expert in forensic genetics was sworn in to this end. However, when the technical examination had been performed, “the possibility of these remains […] belonging to the biological father of Tito lbsen Castro was excluded.” Nevertheless, the State indicated that it had “continue[d] taking steps to identify other places in which the                                                              10 Cf. Case of Ibsen Cárdenas and Ibsen Peña v. Bolivia. Judgment of the Inter-American Court of Human Rights of September 1, 2010. Series C No. 217, paras. 237 and 238. 11 In addition, the State must ensure that, to this end, the competent authorities have available and use all the necessary logistic and scientific resources to collect and process evidence and, in particular, that they have the authority to access pertinent documentation and information to investigate the reported facts and promptly to take those measures and make those inquiries that are essential in order to clarify what happened to Rainer Ibsen Cárdenas and José Luis Ibsen Peña. Cf. Case of Ibsen Cárdenas and Ibsen Peña v. Bolivia. Judgment of the InterAmerican Court of Human Rights of September 1, 2010. Series C No. 217, para. 237.c. 12 Cf. Case of Gelman v. Uruguay. Judgment of the Inter-American Court of Human Rights of February 24, 2011. Series C No. 221, para. 254, and Case of Barrios Altos v. Peru. Merits. Judgment of March 14, 2001. Series C No. 75, para. 41. 13 Cf. Case of Ibsen Cárdenas and Ibsen Peña v. Bolivia. Judgment of the Inter-American Court of Human Rights of September 1, 2010. Series C No. 217, paras. 237.c and 238. 14 Cf. Supreme Decree No. 27089 of June 18, 2003 (file on monitoring compliance, tome II, folio 1029). 6