46 204. When the authorities realized that the MRTA members had been killed by state officials who had used force by means of firearms, the State had the obligation to activate ex officio “and without delay, mechanisms to carry out an appropriate control and verification of the legality of the use of force, 209 through a serious, independent, impartial and effective investigation of the facts at the domestic level.” In the instant case, the Commission notes that the events occurred in April 1997 and, as of the date of this report, fourteen years after the events occurred, a legal ruling has not been handed down by the regular court system in relation to them. 205. The IACHR takes the view that in order to establish whether an investigation has been conducted promptly, it is necessary to take into consideration a series of factors, such as the time that has transpired since the crime was committed, whether the investigation has progressed beyond the 210 preliminary phase, the steps taken by the authorities, and the complexity of the matter. Moreover, the Commission recalls that the Inter-American Court has specified that a prolonged delay may, in itself, constitute a violation of judicial guarantees, and it therefore falls to the State to explain and prove why it 211 has required more time than would be reasonable to deliver final judgment in a specific case, something that it has failed to do in the instant case. 206. Therefore, under the terms of Article 8(1) of the Convention, the Commission will take into consideration, in light of the specific circumstances of the case, the three elements that it has taken into account in its consistent jurisprudence: a) the complexity of the matter, b) the conduct of the judicial 212 authorities, and c) the procedural activities of the interested party. 207. In this regard, the Commission considers that while the instant case might pose a certain degree of complexity in terms of the number of persons dead and accused, it must be recalled that fourteen years after the events, and ten after the case was opened, the latter remains in the oral phase of the trial and no verdict has been delivered. Moreover, as has been proven, the authorities obstructed the performance of a timely and complete autopsy, neglected to open an ex officio investigation for over three years, waited five years to file charges, and have failed to pronounce in a timely manner on different matters. 208. As an example, Vladimiro Montesinos, Nicolás de Bari Hermoza Ríos and Roberto Edmundo Huamán Acurra were ordered released on grounds that the judicial authority had failed to rule on their liability in a timely manner, and therefore “the ordinary period of detention […] had inexorably expired […] and remained in that state for eight months before being returned on July 7, 2004.” Similarly, the lack of a timely ruling on the liability of the accused Fernando Vianderas Ottone, Martín Solari de la Fuente and Herbert Danilo Ángeles led to their acquittal. What is more, nearly four years have transpired since the oral trial began and it has still not been concluded. It is also important to underscore that Mr. Alberto Fujimori was not charged until 2007, and there has been no progress in that case. 209. Finally, in terms of the procedural activity of the interested parties, the Commission notes that, since a death is involved, in other words a crime of public action, the State has the duty to conduct an ex officio investigation, without the need for the participation of the interested parties. Independently of this, the records show that relatives of Eduardo Nicolás Cruz Sánchez and Herma Luz Meléndez Cueva 209 Inter-Am. Ct. H.R., Case of Zambrano Vélez et al v. Ecuador. Merits, Reparations and Costs. Judgment of July 4, 2007. Series C No. 166, para. 122. 210 211 IACHR, Report No. 130/99, Víctor Manuel Oropeza (Mexico), Petition 11.740, paras. 30-32. Inter-Am. Ct. H.R., Case of Ricardo Canese v. Paraguay. Judgment of August 31, 2004. Series C No. 111, para. 142. 212 IACHR, Report on the Merits No. 77/02, Waldemar Gerónimo Pinheiro and José Víctor dos Santos (Case 11.506), December 27, 2002, para. 76. See also Inter-Am. Ct. H.R., Case of López Álvarez v. Honduras. Judgment of February 1, 2006. Series C No. 141, para. 132; Inter-Am. Ct. H.R., Case of García Asto and Ramírez Rojas v. Peru. Judgment of November 25, 2005. Series C No. 137, para. 166; and Inter-Am. Ct. H.R., Case of Acosta Calderón v. Ecuador. Judgment of June 24, 2005. Series C No. 129, para. 105; U.N. doc. CCPR/C/GC/32 of August 23, 2007, Human Rights Committee, General Comment Nº 32, para.35.