39 176. In this regard, the Commission observes that there were a number of irregularities in the collection and preservation of evidence in the instant case. For example: i) the removal of the bodies conducted by the military judge and prosecutor occurred one day after the events and there is no information in the case file to indicate that the crime scene was secured at that time; ii) at least two experts were compelled by the military authorities to sign the report of removal of the bodies even though they were not present at the time; iii) the military judge order that autopsies be performed in a facility that was not equipped for the procedure, namely the National Police hospital, whose staff was not accustomed to performing such procedures; iv) personnel not directly involved in the autopsies were forbidden entry and the professionals involved were not allowed to take photos or videos; v) paraffin tests and ballistics tests to compare the weapons used in the operation were not performed; vi) dental exams were not performed; vi) there was no analysis of the distance from which the bullets found in the bodies were shot; vii) only three of the fourteen bodies were identified, one of them as that of Eduardo Nicolás Cruz Sánchez; viii) the remains of the fourteen MRTA members were buried in secrecy. 177. Those irregularities were confirmed when, in 2001, the Public Prosecutor’s Office requested an analysis of the partial reference autopsies performed on April 23, 1997, to determine the cause of death of the MRTA members. Upon finding that there was insufficient information to do this, the Public Prosecutor’s Office ordered the exhumation of the bodies and the preparation of new reports. Significantly, during the proceedings in the military jurisdiction, it was noted that: The most rigorous and complete expert examinations relating to the thanatological studies of the bodies […] took place more than four years after the events occurred, which means, for example that signs such as powder burns [signo de Benassi] used to determine the proximity of the firearm when it was shot […] are not found […] 178. As indicated by the proven facts and the preceding paragraphs, the State did not preserve the necessary evidentiary material, nor did it act with due diligence in conducting inquiries critical to determining the necessity and proportionality of the use of force employed by the state agents who participated in the operation in which Eduardo Nicolás Cruz Sánchez, Herma Luz Meléndez Cueva and Salomón Peceros Pedraza lost their lives. In the Commission’s view, this clearly demonstrates the failure not only to preserve the related evidence, but also to conduct inquiries essential for an investigation into the events. Opening of investigations into the events 179. The IACHR notes that, after the events occurred, the State neglected to open an ex officio investigation. It was not until after more than three years had transpired that the Public Prosecutor’s Office opened an investigation pursuant to a criminal complaint lodged by the relatives of two of the dead MRTA members. The Commission observes that no investigation of an administrative nature was opened either. In this regard, the Commission recalls that as soon as the State becomes aware that its Security Forces have used firearms and that this has resulted in the death of a person or harm to his personal integrity, it has the obligation to open, ex officio and without delay, a serious independent, impartial and effective investigation. This is derived from the obligation of States to “see that their security forces, which are entitled to use legitimate force, respect the right to life of the individuals 184 under their jurisdiction.” 180. As has been proven, the Public Prosecutor’s Office opened an investigation in May 2002 against 15 commandos of the Operation, the alleged direct perpetrators, and against the presumed 184 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.81; Inter-Am. Ct. H.R., Case of Montero Aranguren et al (Detention Center of Catia) v. Venezuela. Judgment of July 5, 2006. Series C No. 150, para. 66. See also Inter-Am. Ct. H.R., Case of the Miguel Castro Castro Prison v. Peru. Judgment of November 25, 2006. Series C No. 160, para. 238, and Inter-Am. Ct. H.R., Case of Servellón García et al v. Honduras. Judgment of September 21, 2006. Series C No. 152, para. 102.