31 101. In light of this obligation, once the authorities have knowledge of the event, they should initiate a serious, impartial and effective investigation, ex oficio and without delay.75 This investigation should be undertaken utilizing all the legal means available and should be oriented toward the determination of the truth. 102. In addition, this Tribunal Court has also referred to the right of the next of kin of the alleged victims to know what happened and to know who was responsible for the respective events. On the matter, this Court has also stated that: From Article 8 of the Convention it is evident that the victims of human rights violations, or their next of kin should have substantial possibilities to be heard and to act in the respective proceedings, both to clarify the facts and punish those responsible, and to seek due reparation.76 103. The next of kin of the alleged victims have the right to expect, and the States the obligation to ensure, that what befell the alleged victims will be investigated effectively by the State authorities; that proceedings will be filed against those allegedly responsible for the unlawful acts; and, if applicable, the pertinent penalties will be imposed, and the losses suffered by the next of kin repaired.77 104. It is important to note that the obligation to investigate does not derive solely from the Treaty norms of International Law binding upon the States Parties, but also from the domestic legislation that makes reference to the duty to investigate certain unlawful conducts, and from the norms that allow the victims or their family members to present a complaint such that they may participate in the criminal proceedings in order to establish the truth of the events. 105. The Salvadoran Code of Criminal Procedure in force at the time of the events stipulated in Article 50 that “[t]hose entitled to levy an accusation for crimes and misdemeanors that give rise to a proceeding by its own motion, shall be those who are the holders of the right infringed or endangered, their legal representatives, spouse and relatives within the fourth degree of consanguinity or second of affinity, older than twenty years old […]”. Also, Article 86 of the Code of Criminal Procedure established that “[t]he public criminal action will be initiated and monitored by the Public Ministry or by the judge’s own motion, notwithstanding the right to file an accusation according to the law”. 106. In addition, Article 125 of this Code of Criminal Procedure provided that: “Any person older than twenty years old that considers himself aggrieved by a crime that can be prosecuted ex officio, or who without considering himself aggrieved has knowledge of a crime, may file a complaint before the competent judge […].” 75 Cf. Case of the Gómez Paquiyauri Brothers v. Perú. Merits, Reparations and Costs. Judgment of July 8, 2004. Series C No. 110, para. 146; Case of Cantoral Huamani and García Santa Cruz, supra note 10, para. 130; and Case of Zambrano Vélez et al., supra note 10, para. 119. 76 Cf. Case of “Street Children” (Villagrán Morales et al.), supra note 69, para. 227; Case of the Serrano Cruz Sisters v. El Salvador. Merits, Reparations and Costs. Judgment of March 1, 2005. Series C No. 120, para. 63; and Case of the 19 Tradesmen v. Colombia. Merits, Reparations and Costs. Judgment of July 5, 2004. Series C No. 109, para. 186. 77 Cf. Case of Bulacio v. Argentina. Preliminary Objections, Merits, Reparations and Costs. Judgment of September 18, 2003. Series C No. 100, para. 114; Case of the Miguel Castro Castro Prison, supra note 34, para. 382; and Case of Zambrano Vélez et al., supra note 10, para. 115.