C. Investigation, determination, prosecution and punishment, as appropriate, of all those responsible for the facts that are the subject of this judgment c.1 Full investigation and eventual prosecution and punishment of all the masterminds and perpetrators of the massacre 140. The Commission asked the Court to order the State to establish and disseminate the “historical truth” of the events and recommended that the domestic proceedings should continue in order to ensure the effective investigation, capture, prosecution and eventual punishment of those responsible for the alleged human rights violations and to conduct the investigations in an impartial and effective manner and within a reasonable time in order to clarify the events fully, identify the masterminds and perpetrators, and impose the appropriate punishments in accordance with the applicable international standards. 141. Similarly, the representatives asked the Court to order the State to investigate, prosecute and punish all those responsible for the human rights violations committed in this case. 142. In its brief with final arguments, the State indicated its “commitment to individualize, identify and punish those who perpetrated the events of April 28 and 29, 1982.” 143. Bearing in mind its case law,227 the Court establishes that the State must remove all the de facto and de jure obstacles that maintain impunity in this case and open, continue, promote and/or reopen the necessary investigations to individualize, prosecute and punish, as appropriate, those responsible for the human rights violations that are the subject of this case, and establish the truth of the facts, all within a reasonable time, taking into account that more than 39 years have passed since they occurred. In particular, the State must ensure that the following criteria are met: a) Considering the severity of the facts, it may not apply amnesty laws or the statute of limitations, or allege measures intended to exempt responsibility, or take refuge behind arguments such as State secrets or the confidentiality of the information, all of which are actually a pretext for impeding the investigation; b) It must investigate, ex officio and effectively the facts of this case, taking into account the systematic pattern of gross and mass human rights violations that existed at the time in which these occurred. In particular, it must investigate effectively the forced disappearances and forced displacements, the extrajudicial executions, and other human rights violations that were perpetrated, as well as reports that crimes against humanity were committed; c) It must determine the identity of the presumed masterminds of the events. Due diligence in the investigation signifies that all state authorities are obliged to collaborate in the collection of evidence; therefore, they must provide the judge of the case with all the required information and refrain from actions that obstruct the course of the investigation, and d) It must ensure that the different organs of the system of justice involved in the case have the human, material, technical and scientific resources they require to perform their tasks in a satisfactory, independent and impartial manner, and that those who take part in the Cf. Case of Velásquez Rodríguez v. Honduras. Merits, para. 174, Case of the Río Negro Massacres v. Guatemala, supra, para. 257, Case of the Massacres of El Mozote and neighboring places v. El Salvador. Merits, supra, para. 319. 227 43