corresponding proceedings must be publicized so the Guatemalan society may know the facts that are the purpose of the instant case, as well as those responsible for them.334 259. As it has in other cases,335 the Court assesses positively the publication of the report of the CEH, Guatemala: Memoria del Silencio, which includes the case of the Río Negro massacres, as an effort that has contributed to the search for and determination of the truth concerning an historical period in Guatemala. Despite this, the Court considers it pertinent to clarify that the “historical truth” included in that report does not fulfill or substitute for the State’s obligation to establish the truth and ensure the judicial determination of individual or State responsibilities through the pertinent proceedings.336 260. In addition, regarding the State’s observation during the public hearing that Rosalina Tuyuc, expert witness in this case, has not wanted to hand over documentation regarding the presumed rape of several women of the Río Negro community, so that the National Reparation Program can be activated, the Court finds it pertinent to indicate that the monitoring, denunciation and educational activities carried out by human rights defenders make an essential contribution to the observance of human rights, since they act as guarantors against impunity.337 However, the Court reiterates, as it has already in this Judgment (supra paras. 193, 194, 196, 228 and 236), that the investigation into the facts that occurred during the five massacres of the instant case is an obligation that must be complied with ex officio by the State, and that the said investigation should not depend on the procedural actions of private individuals and, especially, merely on the evidence that the can provide. 261. The investigation of the facts is a legal obligation that corresponds to the State, so that each procedural measure that it takes must reflect the commitment assumed by Guatemala in order to eradicate the impunity for the facts, an obligation of guarantee resulting from Article 1(1) of the American Convention. To comply with this obligation, the State must combat this impunity by all legal means available, because impunity “encourages the chronic repetition of the human rights violations and the complete defenselessness of the victims and their next of kin.”338 The State must also “organize the entire government apparatus and, in general, all the structures through which the exercise of public power is expressed so that they are able to legally ensure the free and full exercise of human rights.”339 262. Furthermore, this Court has established in its case law that when a State is a party to international treaties such as the American Convention on Human Rights, the InterAmerican Convention on the Forced Disappearance of Persons, the Inter-American Convention to Prevent and Punish Torture, and the Inter-American Convention on the Prevention, Punishment and Eradication of Violence Against Women, the said treaties are 334 Cf. Case of El Caracazo v. Venezuela. Reparations and costs, supra, para. 118, and Case of González Medina and family members v. Dominican Republic, supra, para. 286. 335 Cf. Case of the Dos Erres Massacre v. Guatemala, supra, para. 232, and Case of Chitay Nech et al. v. Guatemala, supra, para. 234. 336 Cf. Case of Almonacid Arellano et al. v. Chile, supra, para. 150, and Case of Chitay Nech et al. v. Guatemala, supra, para. 234. 337 Cf. Case of Valle Jaramillo et al. v. Colombia, supra, para. 88, and Case of Fleury et al. v. Haiti, supra, para. 80. 338 Case of the “White Van” (Paniagua Morales et al.) v. Guatemala. Merits, supra, para. 173, and Case of Chitay Nech et al. v. Guatemala, supra, para. 236. 339 Case of Velásquez Rodríguez v. Honduras. Merits, supra, para. 166, and Case of Torres Millacura et al. v. Argentina, supra, para. 98. 90